JET ENGINE
1. Duplex ball bearings takes a) axial axial and and radia radiall axis axis effic efficien iently tly b) b) axia axiall loa load d onl only y c) fail fail safe safe load loadin ing g d) – 2. The fig shows a modern turbofan engine, the purpose at the vertex device is a) to diss dissipa ipate te the the heat heat from from the the fan fan cowl cowl b) to streaml streamline ine the the airflow airflow over over the the wing surface surface c) to reduce reduce the turbulance turbulance of airfl airflow ow over the wind wind during during low speeds speeds of flight flight d) to reduce reduce the turbulance turbulance of airfl airflow ow over the wind wind during during high speeds speeds of flight flight 3. A modern turbotantengine fitted a/c flying from Delhi to Madras. The temperature at Delhi is 15°C, while in Madrasis 28°C. to achieve the same power at Madras. a) throttle throttle should should be adjusted adjusted fwd fwd when approaching approaching at Madras b) throttle throttle should should be retarded retarded when approaching approaching madras c) no adjustme adjustment nt is necessary necessary throughout throughout the flight flight d) throttle throttle can be adjusted adjusted either either fwd fwd or retarded retarded to keep keep the Ni rpm constant constant 4. Match the following: a) X-40 steel b) Rene 84 Co c) 6-2-42 Ni d) A286 Ti 5. Fig. a) b) c) d)
pres pressu sure re is is high high in in tube tube A pressu pressure re is high high in in tube tube B pres pressu sure re is is same same thr throu ough gh there will will be rise in in pressure pressure in tube tube B due to to turbulance turbulance
6. In flight CSD oil temp light comes ‘ON’ and the pilot disconnected the CSD. Then it can be connected back a) only only on grou ground nd b) b) only only in flig flight ht c) eith either er on on groun ground d or in in flig flight ht d) automatical automatically ly connect connected ed after after oil oil temp temp is reduced 7. Starter has two holes, for a) alignm gnment ent b) b) breat breathe herr sum sump p ven ventt c) – d) –
8. For the same torque, starter is heavier than starter generator, a) starte starterr generato generatorr has two separ separate ate windi windings ngs 9. In Bryton Cycie DE shows…Fig a) Expa Expans nsio ion n thru thru’’ nozz nozzle le 10. Ni-metalic sensing is fitted on a) pres pressu sure re regul regulat atin ing g valve valve b) FCOC FCOC (fuel (fuel contro controll oil oil cooler cooler)) c) Min Min fl flow val valve d) – 11. A) In FCU, variation in temperatures is compensated by Bi-mettalic disc (or) 12. If the metal found in the chip detector gives white light while wh ile burning, it confirms the presence of a) steel b) Mg c) Cr d) – 13. Exhaust nozzle area is changed due to heat after long operation, it will cause a) the thrus thrustt to reduce reduce for for the amount amount of of fuel flow flow b) the thrust thrust will increase increase with with the increas increasee in EGT EGT c) no appriciabl appriciablee change in thrust thrust or EGT EGT as the area area is same same for that that temperature temperature d) the thrust thrust will will increase increase due to increas increasee of fuel flow flow due to more more airflow airflow through through inlet 14. CODEP means a) coba cobalt lt coa coati ting ng b) coatin coating g given given to LPT blades blades c) coating coating given to improv improvee the corrosion corrosion resist resistance ance in elevated elevated temp temp of turbine turbine blades d) fuel fuel addi additi tive ve 15. Mark the correct statement a) compre compresso ssors rs are are loaded loaded in in front front stage stagess b) compressor compressorss are are loaded loaded more at rear rear stages c) compre compresso ssorr are are equall equally y loade loaded d d) – 16. Kevlar is used in fan casing fabrication. Al foil presence in kevlar a) prev preven entt stre stress ss b) acts acts as a light lighteni ening ng arres arrester ter c) used used in light light freq frequen uency cy oper operati ation on d) –
17. BSI of HPT is done thorough the holes given. During insp the HPT shaft is rotated by a) remove remove starter starter and and rotate rotate through through the the starter starter engagement engagement gears gears b) drive pad pad is given given for this purpose purpose in the AGB sectio section n of these engines engines c) after removing removing the combus combustion tion chamber chamber only, BSI can can be done done d) 7/8” socket socket and spanner spanner attached attached in the hand cracking cracking pad 18. During water methanol injection at which place will increase the temperature a) comp compre ress ssor or inle inlett b) diffuser c) comp compre ress ssor or and and dif diffu fuse ser r d) – 19. Pressurising valve setting at low spring tension causes (or) adjustment of P&D valve on FCU is lower than the normal n ormal then.. a) hot start b) b) hung hung star tart c) – 20. Fog. Of Thrust reverser…identify the component a) bloc blocke kerr door door b) b) drag drag plat platee c) T/R unlock unlock pop-ou pop-outt indi indicat cator or 21. Fig… Identify the bolt used in Hot Section a) A is is use used d in in hot hot sect sectio ion n b) b) B is used used in in hot hot sect sectio ion n c) B or C are are used used in in hot hot sect sectio ion n d) None None of the the abo above ve 22. Fig. Impeller tip speed of centrifugal compressor limits the performance o f the compressor, this is because.. a) tip tip spee speed d reach reachin ing g mach mach no no b) b) exce excess ssiv ivee comp compre ress ssio ion n c) – 23. Fig. Of Magnetic sea a) A is is mag magne neti ticc rin ring g b) b) B is is magn magnet etic ic ring ring c) C is is mag magne neti ticc rin ring g 24. Mark the correct statement regarding usage u sage of the Helical gears used in Turbo Prop gear box a) helical helical gears gears are are easy easy to to manufactu manufacture re and economical economical b) helical helical gears takes more more loads loads because because they they are straigh straightt
25. Dilution of air/fucl air/fucl mix takes takes place in a) ? b) b) inner inner swri swrill vane vaness c) oute outerr swr swril il vane vaness 26. If electronic control box is not fitted on APU, then.. a) load control control valve can can be adjust adjusted ed after after shutdown shutdown of APU b) surge bleed valve operat operates es on when when no load load control control valve c) – 27. APU event marker indicates a) No of APU APU shu shutd tdow own n b) b) No of APU APU sta start rtss c) Over Over temp temper erat atur uree d) Start Starting ing includ including ing hung hung start start 28. The purpose of feedback cable used in Thrust Reverser is a) to prevent prevent fwd fwd thrust thrust selectio selection, n, if they they are in in deployed deployed condition condition b) to bring bring back the thrust thrust lever lever to idle idle in case, the the doors move move opposition opposition to selection in either fwd or reverse c) both both a & b are are corr correc ectt d) – 29. In Hyd. Mechanical Torquemeter torque is senced and transmitted by a) – b) – 30. FCU M.S.B.V. (?) high pressure symbol causes…? a) – b) – 31. For subsonic jet the inlet must have… a) – b) – 32. Fire extinguisher test provides… a) – b) – 33. Compressor fitted with layer turbot in… a) – b) – 34. Compressor blade dia… a) – b) –
35. Thermal efficiency of piston engine is higher than the jet engine is due d ue to… a) – b) – 36. JPT crosses limits due to a) – b) – 37. Inlet of the hyd pump is blocked, then… a) – b) – 38. Efficient combustion cooling is… a) – b) – 39. Trimmer resister on EGT indication system ensures a) a const constant ant res resis ista tance nce val value ue b) increa increase se / decrea decrease se in resist resistanc ancee c) adjust adjust BPT as per requir requireme ements nts 40. In turbo shaft engine above 400 knots of speed increases (25000 ft altitude??) a) before before sonic sonic comp compres ressio sion n is low b) compress compress ratio ratio increases increases above sonic sonic veloci velocity ty c) – 41. Back up to NTS a) TSS b) b) Prop rop brak brakee c) Safe Safety ty coup coupli ling ng 42. Fig. Identify the component a) Fuel pump b) Oil pum pump 43. Fig. Identify the correct cockpit indication d iagram. a) – b) – 44. Fig. Find out the stall angle… a) – b) – 45. Match the following: a) torque cam Turbine rotor b) torque hange compressor
c) snoub d) lock taps
turbine stator combustion chamber
46. After the engine tight up, u p, starter did not cuts off. The probable cause will be a) starte starterr cut cut off off circu circuit it is is fault faulty y b) starte starterr drive drive spring spring is weak c) starte starterr bleed bleed valve valve did did not not clos closee d) eith either er a or b is corre correct ct 47. Rotary air-oil separator is used in a) MGB to drain drain the the oil pack pack sump sump b) AGB to drai drain n the the oil oil back back to sump sump c) Bearin Bearing g sump to to remove remove air air from the the oil drai drained ned d) Located Located in the MGB near near the vent vent outlet, outlet, throws the the oil outward outward to drain drain back in to the sump and allow pressurizing air. 48. Hot shift and cold shift of modern engine is determined by a) CIT CIT senso sensorr probe probe con condi diti tion on b) TIT sensor sensor probe probe conditi condition on c) Throttle Throttle lever lever angle angle and its positi position on in conjunc conjunction tion with with MEC d) ITI sens sensor or and and CIT sens sensor or condi conditi tion. on. 49. Engine anti-icing system consists of ducting and a) heats heats up fwd fwd and rearwa rearward rd simul simultan tanieo ieousl usly y b) heats up fwd fwd and rearward rearward in in cyclic cyclic operati operation on c) consists consists of dual butterf butterfly ly valve, which which regulates regulates the hot bleet bleet air in relation relation with with a timer circuit. d) Can be be used used both both flight flight and ground ground operation. operation. 50. LOP fight illuminated during flight. What are the other parameters in connection with it, the pilot has to check inside the cockpit indicators. a) EGT and and RPM RPM indicat indicator or for the engine malfunction malfunctions. s. b) Ni rpm rpm gauge gauge and oil oil temper temperatu ature re gauge. gauge. c) Filte Filterr cloggi clogging ng ligh lightt and and EGT EGT d) No indicat indicator or to check, but to to cut off the engine engine 51. Igniter, plugs should not be touched with bare hand because a) high radioact radioactive ive material material are used used and it will will cause cause radiation radiation through through the body b) tips are are made up up of tungsten tungsten carbid carbid and it will will get damaged damaged c) – d) – 1. Blade is an angle formed by a line perpendicular to the propeller shaft and line formed by the (a) (a) Rela Relati tive ve wind wind (b) (b) Appa Appare rent nt wind wind (c) (c) Chor Chord d of the the bla blade de (d) (d) Blad Bladee fac facee
2. Thrust produced by a rotating propeller is a result of (a) Prope Propelle llerr slipp slippage age (b) An area area of low pressur pressuree behind the the propelle propeller r (c) An area of decreased decreased pressure immediately immediately in front of the pressure blades (d) The angle of relative relative wind and rotational velocity velocity wind and and rotational velocity velocity of the propeller propeller 3. Propeller blade station number increase from (a) Huh to tip tip (b) (b) Tip Tip to to hul hulee (c) Leadi Leading ng edge edge to to aft aft edge edge (d) Aft Aft edge edge of lead leading ing edge edge 4. It should have high specific gravity (a) (a) Low Low pan pan poin pointt 5. Velocity index should be high. High freezing point – at a cold atm the water contents in the fuel in having tendency to form in a ice crystal 6. It should be filtered to jet engine (a) It should should have low carbon carbon content content after after burning burning the the fuel 7. In twin spool engine, with constant N2, compressor inlet temperature is decreasing then (a) (a) N2 chan change gess (b) Fuel Fuel flow flow incr increas eases es (c) (c) N1 decr decrea ease sess (d) The ratio N1 is maintained constant N2 8. The thrust developed by high bypass ratio engine is (a) (a) Indi Indica cate ted d by by EGT EGT (b) (b) Indi Indica cate ted d by by N2 N2 (c) Propo Proporti rtiona onall fan fan speed speed (d) Not affected affected by ambie ambient nt conditi conditions ons
9. Perceived noise decibel (PNDB) level is low in case of (a) Pure jets without without noise noise suppressor suppressor (b) Straight Straight jet jet with with noise noise suppre suppressor ssor (c) (c) Low Low by by pas passs jet jetss (d) High by by pass jets jets with with acousti acousticc panel panel 10. Ignitor plug spark is due to (a) (a) High High freq freque uenc ncy y (b) High High inpu inputt curr current ent (c) Discharg Dischargee (storage) (storage) capacitor capacitor (d) (d) DC volt voltag agee 11. In a ‘hot tank’ oil system (a) Oil Oil cooler cooler is not not provi provided ded (b) Oil is is stored stored in in a separa separate te tank tank (c) Oil Oil is at high high temp temp in in the tank tank
(d) De-aerat De-aerator or effect effect is very very slow 12. If jet velocity and mass flow is constant for a jet engine then thrust (a) Is maximum maximum when when aircra aircraft ft speed speed is minim minimum um (b) Is maximum maximum when when aircraf aircraftt speed is maxim maximum um (c) Is more when when jet velocity velocity and and inlet velocit velocity y are equal equal (d) Is alway alwayss cons constan tantt 13. Wa Water ter injectio injection n syste systems ms are provides provides for the jet engine engine for the thrust thrust augmen augmentat tation ion the thrust thrust augmentation for water injection can be caused and by two methods. (a) By adding adding or injecting injecting water water at the the compressor compressor inlet inlet (b) By adding adding or injecting injecting water water at the the differ differ section section Fig shown that a water tank made up of aluminum or sheet metal allows the water flow a regulating It then panes to the pressure regulating V/o of the diffuse and compressor inlet thought which water injection in done by providing two manifolds at the diffuse and compressor manifold. A water heater is provided for the water to not formed ice in cold atm or cold weather condition A drain a/v provided to drain full water tank after are it is generally use of after getting sufficient thrust by water injection Water injection system used when aircraft an going to take off
14. In a compressor space between surge line and working lines called (a) Safety Safety margin margin on surge surge margin margin (b) Stable Stable zone zone unsta unstable ble zone zone (c) (c) Unst Unstab able le zone zone (d) (d) Stag Stagge gerr zone zone 15. Hottest zone in turbine engine is (a) Compre Compresso ssorr outlet outlet (b) Turbi urbine ne st (c) 1 stage NGV (d) (d) Exha Exhaus ustt nozz nozzle le 16. In a high by pass engine NGV’s are eliminated (a) (a) To redu reduce ced d nois noisee (b) (b) To redu reduce ce weig weight ht (c) To increa increase se effici efficienc ency y (d) To satisf satisfy y 1 and 2 abov abovee For maximum thrust The thrust augmentation is achieved a the compressor inlet by injecting water at the compressor inlet which increases mass airflow and their by thrust Thrust augmentation is achieved a the diffuser section by injecting water at the diffuser section and which als the diffuser section and decreases the temperature of the diffuser section which gives high deme man airflow high affect to maximum 17. Brayton cycle is (a) Consta Constant nt temper temperatu ature re cycle cycle
(b) Consta Constant nt volum volumee cycle cycle (c) Constant Constant pressure pressure and and constant constant temperat temperature ure cycle cycle 18. NGV’s of turbine are usually (a) Hollow (b) Solid (c) (c) Air Air cool cooled ed (d) As per per (1) (1) & (2) above above 19. Most common defects in combustion chamber is (a) (a) Crac Crack k and and burn burnin ing g (b) Scori oring (c) Pittin tting g (d) (d) Blis Bliste teri ring ng
20. Jet engine ignition system. Jet engine ignition system is a high intensity and dual capacitor discharge type are used The two system are used for the ignition system (a) Low voltag voltagee A.C or D.C D.C type type ignition ignition system system (b) High voltage voltage capacit capacitor or discharge discharge type ignitio ignition n system system 21. High voltage capacitor discharge type ignition system FIGURE SHOWN HIGH VOLTAGE CAPACITOR DISHCARGE TYPE CUT (A.G) A 115 A.C is provided bu E.S.I. but to the primary coil of the transformer A to reduce the noise level a filter cut is provided at the primary After paning 115V at the primary a seen way coil induces a voltage of about 2000V approximately which paner through solid rectifier A through resistance to the dual capacitor or storage capacitor which store the electrically charger In the next cycle a 20000 is paned through rectifier B this resistance 22. Combustion chamber used in a modern jet engines are (a) (a) Can Can ann annul ular ar typ typee (b) (b) Annu Annula larr typ typee (c) Can type (d) As stated stated in 1 and and 2 23. Exhaust nozzle is (a) No neces necessar sary y for jet jet engine enginess (b) Made Made up of tita titaniu nium m alloy alloy (c) Made Made up of of alumi aluminum num allo alloy y (d) A must must for jet engine engine 24. Internal energy of a perfect gas is (a) A functio function n of temper temperatu ature re only only (b) A functi function on of press pressure ure only only (c) (c) Alwa Always ys con const stan antt (d) A function function of temperatu temperature re and pressu pressure re 25. The turbo jet engines (a) Can be used used in thermal thermal power stations as prime stations stations as primer primer movers (b) Are more more effici efficient ent at lower lower altitudes altitudes (c) Work Work on Newto Newton’s n’s third third law law of motion motion (d) (2) and and (3) (3) above above are corr correct ect
26. Compression process in axial compressor is (a) (a) Isot Isothe herm rmal al (b) (b) Adia Adiaba bati ticc (c) Isob sobaric aric (d) (d) Isom Isomet etri ricc 27. Compressor pressure ratio of an engine compressor depends upon (a) (a) Ambi Ambien entt press pressur uree (b) Ambient Ambient temper temperatur aturee and ambient ambient pressur pressuree (c) Speed Speed and ambi ambient ent pres pressur suree (d) Speed Speed mass airflo airflow w and ambient ambient tempe temperatu rature re The energy stored in a dual capacitor and storage charger at a fule charge level and then tenses the tube this caused charger when fully developed it induces in the primary winding of the transformer (TRIGGER), which is of up to app 2000 V This induces a appx of 20,000V to the secondary of the tram former winding and which gives high intensity current flow thr ignite plug which gives spark A bleeder resistance are provided for troiger capacitor to give protection for excess voltage Two igniter plug are used for capacitor discharge type cht for alternate operations 28. The fuel nozzles used in modern gas turbine engines (a) Are Are alwa always ys of of dual dual type type (b) Are identic identical al for engine engine with same same power power rating rating (c) Are welde welded d to the the combusti combustion on chambe chamber r (d) Is the last compon component ent in the the fuel fuel system system 29. Anti – icing system used on jet aircrafts (a) Is fully fully automa automatic tic (b) Is to be be used only only to to melt melt the ice ice formed formed (c) Never Never makes makes use of electr electrical ical heaters heaters (d) Need not be be used used thought thought the the flight flight 30. How many igniters are usually used on a turbine engine having nine burner cans? (a) One (b) Two (c) Three (d) Nine 31. The material used for jet engine is following main fine types (a) Titani tanium um (b) Aluminum Aluminum or Aluminum Aluminum alloy (c) (c) Nick Nickel el bar baree allo alloy y (d) Nicke Nickell chrom chromee alloy alloy (e) Steel Steel or or stainl stainless ess steel steel Titanium are high resistant to 1000 & corrosion and are used for fan blades and sometime for compressor vanes Aluminum or aluminum alloy are used for jet engine for its light weight characteristics it is high resistant to corrosion heat Nickel- chrome alloy’s re used fore turbine blades, which stands for high temperature Steel or stainless steel alloy are used for rota vane or staten vane in an axial flow type jet
32. In an axial flow turbine engine, compressor bled air is sometimes used to aid in the cooling of (a) Oil (b) IGV (c) (c) Fuel Fuel cool cooler er (d) Turbi urbine ne 33. Which of the following turbine fuel filters has the greatest filtering action? (a) Micron (b) (b) Wire ire mes mesh h (c) (c) Wa Wafe ferr scre screen en (d) Stacke Stacked d charco charcoal al 34. For starting a turbine engine (a) D.C D.C motor motor is neve neverr used used (b) Very very very low cranking cranking speeds speeds are requir required ed (c) Igniti Ignition on is is neces necessar sary y (d) Statemen Statements ts 2 and 3 are corre correct ct 35. Mechanical integrity of the turbine as well as engine operating conditions of the engine can be checked by (a) Engine Engine oil pressu pressure re (b) Exhaus Exhaustt gas temper temperatu ature re (c) Engine Engine oil oil temp temper eratu ature re (d) Engine Engine pres pressur suree ratio ratio 36. Which parameter will determine engine power? (a) EGT EGT and and vibrat vibration ion mete meter r (b) RPM RPM and and oil oil press pressure ure (c) RPM RPM and and fuel fuel pressu pressure re (d) (d) EPR EPR OR OR RPM RPM 37. Mark the correct statement (a) Thrust Thrust rever reverse se reduce reducess landing landing roll (b) Oil pressure pressure for for jet engine engine is always always regulate regulated d (c) VSV’ VSV’ are not not provided provided on on modern modern jet engine engine (d) By providin providing g fire fire wall wall in the engine engine cowl compar compartme tment nt engine engine fire detectio detection n elemen elementt can be eliminated
JET ENGINE JUNE – 2002
1. EGT measuring thermocouples are connected in (a) Series (b) (b) Para Parall llel el (c) (c) Seri Series es para parall llel el 2. Angle of attack of a propeller is (a) Angle Angle between between chord chord line and and plane of rotations rotations (b) Angle Angle between between chord line line and relativ relativee wind direction direction (c) Angle Angle between between chord line and longitu longitudinal dinal axis axis the aircraft aircraft 3. Mark the correct statement (a) Geometri Geometricc pitch is the distance distance travele traveled d by propeller propeller in one rotations rotations
(b) Effective pitch pitch is the the actual distance traveled traveled by the propeller in on rotations (c) Slip is is the difference between between geometric geometric pitch pitch and effective pitch (d) (d) All All of the the abov abovee 4. Mark the correct statement regarding propeller tracking (a) Propeller tracking is is determining determining tip position relative to others propeller propeller (b) Static Static balancing balancing of prope propeller ller (c) Dynamic Dynamic balancing balancing of propeller propeller (d) (d) All All of the the abov abovee 5. Mark the correct statement (a) In alpha alpha range range blade angle angle is contro controlled lled by gover governor nor 6. Compressor blades are attached with disc (a) Dove ove ta tail (b) Fir tree with various various locki locking ng (c) --------------------------------------------(d) (d) as abo above ve (a) (a) & (b) (b) 7. Reduced cooling air requirements by 50 percent and decreased wt. By 20% is in which system (a) (a) Airf Airfli lim m cool coolin ing g (b) Trans Transpir pirati ation on coolin cooling g (c) Imperg Impergeme ement nt coolin cooling g (d) Finw inwall 8. Mark correct statement regarding gas turbine igniter (a) Gap is more engine engine to reciproca reciprocating ting because because operating operating provisio provision n (b) As (a) (a) and and less less fouling fouling problem problem (c) As (b) and high high ener energy gy (d) (d) As (c) (c) and and Condition lever (propeller lever) controls – free power turbine (Nf) Power lever (Throttle) (Throttle) controls - FCU & has generator generator turbine (N8) If instruction indicating high / rise then compressor combination If instruction indicating low / decrease then turbine de effectors 9. Shrouding of turbine blades (a) (a) Redu Reduce cess tip tip los losss (b) As (a) (a) prevent prevent excessive excessive vibration vibration (c) As (b) (b) and and preven preventt twist twisting ing (d) As (c) and operat operatee cool as extra extra mass in tip at reduce reduced d speed 10. Mark correct statement (a) Thrust Thrust reverse reverse is is used in the fan dischar discharge ge (b) 50% rever reverse se thrust thrust provide provided d 35 to to 50% (c) Core engine engine exhaust exhaust is used used for forward forward thrust thrust (d) (d) All All the the abov abovee 11. Wet thrust rating is (a) Wa Water ter injec injectio tion n is on (b) Cooli Cooling ng perio period d of engin enginee (c) Wa Water ter injec injectio tion n off off (d) (d) Diff Diffus user er 12. Water is injected in compressor inlet and difficult then (a) Surge Surge line line shift shiftss down down
(b) Surge Surge line line shift shiftss away away 13. Speed droop is common to all mechanical governors to reduce these problems (a) (a) Use Use a weak weaker er spr sprin ing g (b) Make meter metering ing valve valve narrow narrow radiall radially y (c) Decrease Decrease pressure pressure differ difference ence across across metering metering valve valve (d) (d) All All of the the abov abovee 14. Mark the correct statement (a) Paper Paper cartage cartage type type filter filter used used in low preside preside (b) As 1 and screen screen disc disc type type filter filter used I hi hi pr side (c) As 2 and (d) (d) All All of the the abov abovee 15. For lubrication (a) Hi viscosi viscosity ty index index oil oil lis lis requir required ed (b) Hi acid acidity ity oil is used used (c) Hi pour pour point point oil oil is is used used (d) (d) All All of the the abov abovee
16. Mark the correct and statement (a) Scavenge Scavengerr pump is centrifu centrifugal gal type of the the larger larger capacity capacity (b) Pr pump is centri centrifugal fugal type (c) Scavenge Scavengerr pump capacit capacity y is smaller smaller than than Pr. Pump Pump (d) Both Both pump pump are are gear gear type type 17. Pressure relief valve pr I equipped with centrifugal boast arrangement (a) Boost Boost pump pump pres pressur suree (b) (b) Main Main pump pump pr (c) Filter lter pr (d) (d) All All of the the abov abovee 18. In starter generator (a) Two Two field field wind winding ing are are used used (b) One common common armat armature ure is used (c) Starter Starter is used for startin starting g of generator generator for electrica electricall power (d) (d) All All of the the abov abovee 19. In gas turbine engine (a) Starter Starter is discon disconnecte nected d as soon as light light off off (b) Starter Starter is on to to give specif specified ied speed speed to engine engine 20. In performance monitor ring all parameter are in increasing order then it shows failure (a) Turbi urbine ne (b) (b) Comp Compre ress ssor or (c) (c) Comb Combus usti tion on (d) (d) In let let guid guidva vave ve 21. During starting fire, fire extinguisher is discharge (a) (a) Engi Engine ne is is clea cleane ned d (b) Engine Engine replace replaced d and sent sent to to shape shape 22. Blending is done to (a) Recoun Recounter tering ing the blade blade
23. For the maintenance purpose engine is divide in the two section, in hot section (a) Turbine Turbine combustio combustion n exhaust exhaust nozzle nozzle (b) Turbine, Turbine, diffuser, diffuser, exhaust exhaust nozzle nozzle (c) HP compress compressor, or, combusti combustion, on, exhaust exhaust nozzl nozzlee (d) HP compr compressor essor,, combusti combustion, on, turbi turbine ne
24. FCU senses (a) Rpm (b) (b) As I and and CDP CDP (c) (c) As 2 and and EDP (d) (d) AS 3 AND AND cip cip 25. In helicopter which engine is used (a) (a) Turb Turbo o sha shaft ft (b) (b) Turb Turbo o fan fan (c) Free Free power power turbin turbinee (N1) (N1) (d) Abov bove 1 & 3 26. Advantage of centrifugal compressor (a) Hi pr rati ratio o per per stag stagee 27. In convergent nozzle used in supersonic speed (a) Pr. Increased Increased volume volume decreased decreased (b) Veloc Velocity ity incre increase ased d 28. Bleeding check (a) Bleed Bleed valve valve closed closed (b) (b) Blee Bleed d valv valvee open open (c) Varia Variable ble stat stator or vane vane close close 29. TSFC is (a) Directly Directly proport proportiona ionall to compress compression ion ration ration (b) (b) Indi Indire rect ctly ly 30. Mark correct statement (a) Thrust due to pr fall fall is more more than thrust thrust increase increase due to temperature temperature fall fall 31. Mark correct statement (a) Most compres compression sion engines engines using annular annular combusti combustion on chamber chamber (b) Can – annular annular is best best efficien efficientt 32. Which one is fuel flow rate indicator without motor (a) Vane type (b) Impell Impeller er – turbi turbine ne type type 33. Mark the correct statement (a) Red radial radial line line is maximu maximum m permissib permissible le range range 34. In two wire thermal switch fire detecting (a) Open circuit circuit will give indication indication
35. In modern vibration indication system (a) It consists consists of pick pick – up, signal signal conditiona conditionall indicator indicator (b) Later Later – piezoelec piezoelectric tric – accel accelerat eration ion (c) Later Later – elect electromec romechanic hanical al velocit velocity y 36. Rhumble occurs (a) P & D valve valve malf malfunc unctio tion n (b) FCU FCU malfun malfuncti ction on (c) Fuel nozzle nozzle parti partially ally clogged clogged (d) (d) All All of abov abovee 37. Which component is not mounted on engine (a) (a) Boos Boostt pump pump (b) (b) Pres Pressu sure re pump pump (c) P & D va valve lve 38. Mark correct statement regarding oil pressure indicating system (a) (a) Ther Thermo moco coup uple le (b) Autos utosy yn (c) (c) Temp Temper erat atur uree buld buld 39. Anti icing valve is used for (a) To avoi avoid d ice ice forma formatio tion n (b) ----(c) ---(d) --40. In fuel metering valve (a) Orifi Orifice ce area area is vari varied ed (b) A constant constant fuel fuel pressu pressure re across across valve valve (c) (c) 1 2 2 are are corr correc ectt (d) -----------41. Which is fire-extinguishing fire-extinguishing agent (a) Freon (b) Bromochlo Bromochloro ro diflorome difloromethane thane (c) Bromo Bromo fluoro fluoromet methan hanee (d) (d) All All of the the abov abovee 42. Triming is carried out when (a) (a) FCU FCU is is cha chang nged ed (b) Specif Specific ic gravi gravity ty of fuel fuel (c) For perf perform ormanc ancee recove recovery ry (d) (d) All All of the the abov abovee
SUBJECTIVE QUESTIONS
1. a. Explain active clearance control in the modern turbo fan engine b. Method of turbine blade cooling with fig c. Field cleaning 2. a. Explain the breather system with diagram b. Show thrust Vs air speed of turboprop turbofan and turbojet engine 3. a. In axial flow compressor why gas flow path is made convergent explain
b. What is the advantage of squalor blades? c. What is bleed band how to check explain? 4. a. If mass mass flow flow rate rate is 60 lb/s lb/sec ec/e /eng ngin inee and and exha exhaus ustt gas gas velo veloci city ty is 1300 1300 ft sec sec for for a turbojet engine ready for the take off find out gross thrust of each engine b. Draw by graph effect air thrust for following variable (i) Speed of a/c (ii) RPM (iii) Altitude (iv) OAT 5. a. Which type of turbine is used in air turbine starter explain b. What is engine inlet roster clissipate c. Advantage of reverse flow combustor, explain the work d. What are advantage of free power turbine and where it is used?
ANSWERS
1
C
11
A
21
A
31
A
41
D
2
C
12
B
22
A
32
A
42
D
3
D
13
A
23
A
33
A
4
A
14
D
24
A
34
A
5
A
15
A
25
A
35
A
6
D
16
D
26
A
36
D
7
D
17
B
27
A
37
A
8
A,D
18
D
28
C
38
B
9
D
19
A
29
B
39
A
10
D
20
B
30
A
40
C
JET ENGINE
JUNE 1998 SESSION
1. Internal energy of a gas depends upon its (a) Press essure ure (b) (b) Temp Temper erat atur uree (c) Volume (d) (d) None None of of the the abov abovee 2. When mechanical energy is converted into heat energy or vice versa an exact equivalent exists between the two. This is stated in the (a) First First law law of thermody thermodynamic namicss (b) Second Second law law of therm thermodyna odynamics mics (c) Third Third law of ther thermod modyna ynamic micss (d) (d) None None of of the the abov abovee 3. During starting an engine stabilizes at idle r.p.m and JPT (a) Check Check for whethe whetherr oil pressur pressuree is correct correct (b) Check Check for whether whether oil oil temperat temperature ure is correc correctt (c) Check Check for whether whether genera generator tor output output is correc correctt (d) All All of the the above above corr correct ect 4. Mark the correct statement (a) Fuel trimmer trimmer is provided so that the relationship relationship between between fuels flow an r.p.m. r.p.m. Can be varied without using fuel lever (b) Because the mass flow inside the engine change with atmospheric atmospheric conditions conditions (c) Trimmer Trimmer is is adjusted adjusted to to provide provide given given JPT. JPT.
(d) All All of the the above above are are corre correct ct 5. During start engine rotates but fails to light up one suspect (a) Igniti Ignition on sys system tem fault fault (b) Fuel pressure pressure control control system system fault fault (c) (c) Both Both a and and b (d) Batter Battery y capac capacity ity is is low 6. During inspection of centrifugal compressor blades normally (a) No crack crack is allowed allowed in the leading leading edge trailin trailing g edge and blade blade tips (b) Negligible crack is allowed allowed as in in (i) up to minimum minimum extend possible possible and under under constant monitoring (c) Nicks dents in the leading leading edge, trailing edge edge and blade tips not allowed allowed (d) (d) None None of of the the abov abovee
7. The lowest r.p.m. at which a rotating object vibrates (a) (a) Reso Resona nanc ncee (b) Natural Natural frequency frequency of vibrat vibration ion (c) (c) Harm Harmon onic icss (d) (d) All All of the the abov abovee 8. (a) At high power settings the noise generated from the compressor blade is (b) Noise from the compressor is of lower frequency (c) Low frequency sounds can be attenuated easily (d) None of the above
predominant
9. Characteristics of P & D valve (a) Dump valve is sprin spring g loaded loaded close close (b) Pressuri Pressurizing zing valve valve is spring spring loaded loaded open open (c) Pressuri Pressurizing zing valve limits limits starting starting fuel to primary primary manifold manifold (d) (d) All All of the the abov abovee 10. In a jet engine V.S.V and variable I.G.V are a part of (a) High High pres pressur suree syste system m (b) Low pressu pressure re syst system em (c) (c) Acce Access ssor ory y driv drivee (d) (d) None None of of the the abov abovee 11. Modular construction in a jet engine (a) Enables Enables mainte maintenance nance with limit limited ed repair repair (b) Enables Enables mainte maintenance nance with major major repair repair (c) Modular Modular maintenan maintenance ce involves involves more of repair rather rather replacement replacement (d) (d) Both Both b and and c 12. Smoke from tail pipe. Most probable cause is (a) Main oil filter filter contamina contaminated ted (b) Blocked Blocked scaveng scavengee port of of bearing bearing housing housing (c) (c) Both Both a and and b (d) (d) None None of of the the abov abovee 13.In a flight from Delhi to Bangalore, excess oil was consumed than required most probable cause could be (a) Defectiv Defectivee centrifug centrifugal al breather breather carbon carbon seal seal
(b) Main oil filter filter contam contaminati ination on (c) Oil Oil leak from from contam contamina inatio tion n (d) (d) Both Both a and and b
14. In the relation P.V X T the term X is proportional (a) Mass Mass of the the gas gas mole molecul cules es (b) No of gas molecu molecules les (c) Pressure Pressure volume volume and and tempe temperatu rature re (d) Average Average K.E K.E of of the molecule moleculess 15. If a system is perfectly conducting to the surroundings and the temp remains constant the process is (a) (a) Isot Isothe herm rmal al (b) (b) Adia Adiabe beti ticc (c) (c) P.V P.V cons consta tant nt (d) (d) Both Both b and and c 16. An aircraft is designed to fly at 350 m.p.h. (a) Jet engi engine ne becom becomes es the choi choice ce (b) (b) Prop Propel elle ler r (c) (c) By pass pass engi engine ne (d) (d) None None of of the the abov abovee 17. An airplane has an engine providing 4000 lb thrust at 300 m.p.h the thrust horsepower is (a) (a) 4000 4000 b.h. b.h.p. p. (b) 3200 (c) 12800 (d) 5000 18. Increase in the turbine disc diameter under hot running (a) (a) Disc Disc gro growt wth h (b) (b) Disc Disc rock rock (c) Has effect effect of reducing reducing tip clearance clearance as engine engine run time increas increases es (d) (d) All All of the the abov abovee 19. When change in pressure and volume of a gas take s place without change in temperature the process (a) (a) Is very very slow slow (b) Obeys Obeys boyle’ boyle’ss law law (c) Adiaba Adiabatic tic chan change ge is quic quick k (d) (d) All All of the the abov abovee 20. Oil pressure continuously fluctuates (a) Indica Indicates tes is faulty faulty (b) Pressure Pressure relief relief valve valve is sicking sicking and contami contaminated nated (c) (c) Both Both a and and b (d) Oil check check valve valve setti setting ng is improper improper
21. After flight is over engine does not shut down (a) Loose Loose connecti connection on of power power lever lever linkage linkage (b) Fuel control control shut off valve valve is faulty faulty (c) Power Power lever lever rigging rigging is improper improper (d) (d) All All of the the abov abovee
22. After engine starts the engine hesitates for 5-6 seconds go for (a) Surge Surge bleed bleed valve valve check check (b) Solen Solenoid oid cont control roller ler chec check k (c) Fuel Fuel pump pump func functio tional nal chec check k (d) (d) All All of of the the abov abovee 23. During testing of engine, hooting/ humming sound is heard (a) Operation Operation of compr compressor essor bleed bleed valve valve is improp improper er (b) Condition Condition of the the bleed bleed valve diaphr diaphragm agm is bad bad (c) (c) Both Both a and and b 24. For M.E.C and P.M.C (a) M.E.C provides provides an electronic electronic override override of P.M.C P.M.C to set set corrected corrected fan speed (b) P.M.C provides provides an electronic electronic override override of M.E.C M.E.C to set set corrected corrected fan speed (c) P.M.C P.M.C is locate located d in the the tail of the engine engine (d) (d) None None of of the the abov abovee 25. Start valve can be operated (a) Manu anuall ally (b) (b) Elec Electr tric ical ally ly (c) Opening Opening /closing /closing is indica indicated ted by pneumat pneumatic ic pressure pressure (d) (d) All All of the the abov abovee 26. In engine starter system (a) Compressed air pressure pressure is is converted converted to rotational mechanical energy (b) Reduction mechanism mechanism of gear train train converts low speed high torque of turbine wheel wheel into high specific low require through a pawl and ratchet mechanism (c) Starter Starter operation operation is not not controlle controlled d by start valve valve (d) (d) None None of of the the abov abovee
ANSWERS
1
B
11
A
21
B
2
A
12
B
22
?
3
D
13
D
23
?
4
A
14
C
24
B
5
?
15
B
25
?
6
A
16
B
26
?
7
B
17
B
8
A
18
B
9
C
9
B
10
A
20
B
Jet Engine (Fed 2003 Session)
1. If jet velocity is 1288ft sec & airflow is 125lb what will be thrust produced? (a) 4000 lb (b) 6000 lb lb (c) 5000 lb (d) 3500 lb lb 2. If atmospheric temperature change but EGT remains unchanged during ground run but every define high power cruise flight then snag/fault is in (a) CIT (b) CDP (c) FCU (d) FCU FCU altitu altitude de adjus adjuster ter 3. In a turbo fan engine airflow is 60 lb in both fan and core engine exhaust and velocities are sec & -------ft / sec what will be thrust produced? (a) 1433 lb (b) (b) -------------lb lb (c) 5433 lb (d) (d) -------------lb lb 4. CIT indicator in turbojet engine is (a) Copper Copper constr constrain aintt (b) (b) Nick Nickel el plat platin inum um
(c) (c) Chro Chrome mell alu alume mell (d) (d) All All of the the abov abovee 5. FACDEC means (a) Full author authorized ized digita digitall electroni electronicc control control (b) Full author authorized ized digital digital electr electronic onic control control 6. Synchronous motor type fuel quantity gage measures (a) (a) Fuel Fuel volu volume me flow flow (b) (b) Fuel Fuel mass mass flow flow (c) Its same of vane vane type indicator indicator (d) As 02 02 & 03 7. In water injection system EGT is increased water injected at (a) Inlet (b) (b) Diff Diffus user er (c) Nozzle (d) Simultan Simultaneous eous inlet inlet & diffuser diffuser
8. If water injection is ON then (a) N1 spool spool shifts shifts towards towards stall stall margin margin (b) N1 spool spool shifts shifts away stall stall margin margin (c) N2 spool spool shift away stall stall margin margin (d) N1 & N2 shift shift away away stall stall margin margin 9. High power to weight ratio is (a) (a) Star Starte terr mot motor or (b) Starte Starterr gene generat rator or (c) Air Air turb turbine ine starte starter r (d) (d) Rach Rachet et & paw pawll 10. During installation of thermocouple length of sensor is increased then (a) (a) Unde Underr read read (b) (b) Over Over read read (c) (c) Equa Equall read read (d) (d) None None of of the the abov abovee 11. During feathering of the propeller (a) (a) Pitc Pitch h angl anglee fine fine (b) Pitch Pitch angl anglee course course more more (c) Pitch Pitch angle angle negati negative ve (d) As 1 & 2 12. Aluminum propeller is cleaned by (a) Acid (b) A caus caustic tic soluti solution on (c) (c) None None of of the the abo above ve 13. Due to fatigue stress in turbine blade (a) (a) Chan Change ge of shap shapee (b) Cracks Cracks in the trailing trailing & leading leading edge perpendicu perpendicular lar to length length (c) (c) Leng Length th wil willl grow grow (d) (d) All All of the the abov abovee
14. Due to fatigue stressing turbine blade (a) (a) Chan Change ge of shap shapee (b) Cracks Cracks in the trailing trailing & leading leading edge perpendicu perpendicular lar to length length (c) (c) Leng Length th wil willl grow grow (d) (d) All All of the the abov abovee Answers: 1 – c, c, 2 – a, 3 - , 4 – b,c, 5 – b,c, 6 – b, 7 – a, 8 - , 9 – c, 10 – a, 11 – a, 12 – c, 13 – d.
15. In which engine air speed kinetic energy at inlet is not changed in the static energy (a) Turbo urboffan (b) (b) Turb Turboj ojet et (c) (c) Turb Turbo o sha shaft ft (d) (d) Turb Turbo o pro prop p 16. Synchronous system in propeller is used in (a) Single Single engine engine to equal equal the the blade blade angle angle (b) Multieng Multiengine ine to allow allow same same speed speed of engines engines (c) As 1 & reduce reduce vibra vibratio tion n (d) (d) All All the the abov abovee 17. During flight which fault is not monitored by performance monitoring (a) (a) EPR, EPR, EGT, EGT, PRM PRM (b) EPR, EPR, EGT EGT max, max, CIT (c) (c) CIT, CIT, CDP CDP,, EGT EGT max max (d) CIT, CIT, CDP CDP.. EGT, EGT, RPM RPM 18. If oil is found in exhaust (a) (a) Repl Replac acee eng engin inee (b) Seal leakage leakage at at bearin bearing g shaft shaft (c) Carbon Carbon seal seal leakage leakage in in turbine turbine shaft shaft (d) Scave Scavenge nge pump pump failur failuree 19. Mark the correct statement (a) Pressure Pressure pump pump capacity capacity is greater greater than scavenge scavenge pump capaci capacity ty (b) Scavenge Scavenge pump pump capacity capacity is greater greater than than pressure pressure pump (c) Both Both pump pump capaci capacity ty are are same same (d) -------------------------------------------------------------------20. Gas velocity is high at (a) Inlet (b) (b) Comp Compre ress ssor or (c) Turbi urbine ne (d) (d) Diff Diffus user er 21. Mark correct statement (a) Superviso Supervisory ry EEC EEC develops develops command command top actuate actuate FCU FCU (b) Superviso Supervisory ry EEC EEC directly directly contro controls ls FCU (c) Supervisory EEC and sigma sigma Hydro-mechanical Hydro-mechanical fuel control control unit unit (d) (d) All All of abov abovee
22. Mark correct statement (a) ACC control controlss tips clearan clearance ce by cooling cooling turbine turbine case case (b) -----------------------------------------------------------------------------------------------------------------------(c) -----------------------------------------------------------------------------------------------------------------------(d) -----------------------------------------------------------------------------------------------------------------------23. Mark the correct statement (a) Turbo Turbo jet engine engine has has lowest lowest TSFC TSFC (b) Turbo Turbo fun has has better better hot day perfor performance mance (c) Turbo Turbo fan has has lowest lowest TSFC TSFC up to to 400 mile mile / hour hour (d) (d) All All of the the abov abovee 24. Mark correct statement (a) Actual power power output of engine as compared compared to the the horsepower horsepower in fuel is thermal thermal efficiency (b) Propulsiv Propulsivee efficienc efficiency y is the thermal thermal efficiency efficiency Answers: 14 – d, 15 – c, 16 – b, 17 – c, 18 – b, 19 – b, 20 – c, 21 – c, 22 – a, 23 – c, 24 – a.
25.What is the effect of combustion emissions? (a) Popul Populate atess surrou surrounde nded d area area (b) (c) (d) 26. EPNAB means effective perceived noise decibel (a) Sound is dissi dissipated pated at distan distance ce (b) ______ _________ ______ ______ ______ ___
(c) It is standard standard measure measure of the loudness loudness (Sound or) combined with frequency frequency and duration duration of sound sound and is used specify for a/c noise in hemisphere (d) Soap - spectrographic spectrographic oil analysis analysis port – spectrum tric oil analysis analysis program 27. Mark the correct statement (a) In the flight flight CDP CDP failure failure cause cause to run run engine engine in idle idle (b) During During starting starting CDP CDP failure failure cause cause huy start start (c) During During ground ground CDP failure failure will will cause cause to run engine engine idle (d) Any time time CDP failur failuree to run engine engine higher higher rpm rpm 28. Polished shaft is used for which bearing (a) (a) Carb Carbon on bear bearin ing g (b) Labyr Labyrint inth h bear bearing ing (c) (c) Nylo Nylon n bear bearin ing g (d) (d) All All of the the abov abovee
29. Trimmer coil add in ignition system is (a) (a) Conv Conver ertt AD AD to to DC DC (b) (b) Conv Conver ertt DC to AC AC (c) (d) 30. Difference between hi voltage of 10-voltage ignition (a) Hi voltages voltages have high high energy energy than than 10 voltages voltages (b) Hi (c) (d) 31. During oil analysis mg is gived Hi then a practice gear of problem in gearbox Answer: 25 - , 26 - , 27 – b, 28 – a, 29 – b, 30 – a, 31 - .
JET ENGINE SUBJECTIVE (FEB 2003 SESSION)
1. What is cascade, how it helps turbofan / turbojet engine explain? 2. Wright the types of thrust reverser. Explain mechanical blockage type with sketch 3. What are the advantage & disadvantage of centrifugal compressor? 4. What is primary principal of pressurization breather system explain pressurization breather system with sketch how it works? 5. What is vortices dissipater explain with sketch? 6. Explain the operation of HMF unit metering vale with sketch? 7. What are causes of oil temperature high give remedial action for each cause? 8. What are the combustor emissions give their effect?
9. Wright the operating principal of turbojet and ice separator inlet screen? 10. What are the forces acting on rotating propeller explain each? 11. Wright principal of Hamilton propeller feathering with sketch? 12. Explain the procedure for finding ------------ of the oil engines? 13. What is slip explain? 14. Explain how turbofan engine is replacing turboprop engines 15. What are the FOD avoiding precautions turboprop engines? 16. Using Newton’s seonel 100 of notion derive formula for thrust calculation 17. What is the not streak explain give reason for streak 18. FFX, FPM & EGT northern what are causes remedial action?
32. In the good combustion chamber (a) (a) Incr Increa ease se veloc velocit ity y (b) Diffus ffusee (c) Conver Convertt pr to kinet kinetic ic energy energy (d) As 1 or 2 33. In hi (a) (b) (c) (d)
energy capacitor ignition system In hi energy energy capacit capacitor or igniti ignition on system system Hi energy energy is is produce produced d spark spark Hi energy energy is is produced produced spark spark using using short short time time Lo energy energy is produce produced d spark using using short short time time
34. Acceleration of deceleration is controlled for (a) Blow Blow out provis provision ion (b) Crack Crack of leading leading of blade blade and and case case (c) Expansion Expansion and contrac contraction tion of blade and case case (d) None of the the above above are are correc correctt 35. In HMF unit hydro mechanical fuel unit (a) Valve Valve area area is varied varied (fixe (fixed d pr. df) (b) (c) (d) 36. For good lubrication oil used synthetic oil (a) Minimum Minimum wax sulpher sulpher us us sedime sediment nt (b) Operates Operates in hi temp temp is gives gives low vapour vapour (c) Very Very load load carryin carrying g capacit capacity y (d) (d) All All of the the abov abovee
37. If anti ice valve is operative in flight then what is positive mean of finishing that anticity system working properly (a) (a) EGT EGT incr increa ease se (b) RPM RPM & EPR EPR fluctu fluctuati ation on (c) (c) Fuel Fuel flow flow rate rate (d) As in in 1 & 2 Answers: 32 – b, 33 – b, 34 – a, 35 - , 36 – d, 37 – a, d.
JET ENGINE (JUN 2003 SESSION) TOTAL MARKS 80
TIME 2 HOURS
1. Torque meter is used in (a) Turbo urboffan (b) (b) Turb Turbo o shaf shaftt (c) (c) Turb Turbo o prop prop (d) (d) All All of the the abov abovee 2. Mark correct statement (a) Throttle control & propeller control control is interconnected interconnected I the ground operation operation (b) In flight propeller control is interconnected in the ground operation operation (c) ------------------------------------------------------------------------------------------------------------------------------------------------------------(d) Both oth 1 & 2 3. If throttle of constant speed propeller is reduced slightly (a) Pitch Pitch angle angle reduc reducee (b) Pitch Pitch angle angle incr increas easee (c) Pitch Pitch angl anglee remai remains ns same same (d) Pitch Pitch angl anglee will will rever reverse se 4. Antiicing operation check is viewed by (a) Fluctu Fluctuati ation on of RPM RPM (b) Fluctu Fluctuati ation on of of EPR EPR (c) Flick Flickeri ering ng of antiici antiicing ng valve valve (d) (d) TGT TGT inc incre reas asee 5. Notch in turbine blade is (a) (a) To meas measur uree wear wear (b) (b) Reli Reliev evee stre stress ss (c) (c) Givi Giving ng thic thickn knes esss (d) Air se seal 6. Aluminum propeller blade cleaning is done by (a) Acid (b) Causti Causticc soda soda wash wash (c) None 7. Mark the correct statement
(a) (a) (b) (b) (c) (c) (d) (d)
Gove Govern rnor or spe speed ed pro progr gres essi sive vely ly inc incre reas ases es as as load load add added ed Gove Govern rnor or spee speed d prog progre ress ssiv ivel ely y decr decrea ease sess as load load adde added d Gove Govern rnor or spee speed d rem remai ains ns cons consta tant nt as load load adde added d Gove Govern rnor or spee speed d rem remai ains ns cons consta tant nt as load load remo remove ved d
8. Mark the correct statement (a) Governor Governor droop droop is decrea decrease se of speed speed when load load added added (b) Governor Governor droop droop is increase increase of speed speed when load load unloaded unloaded (c) Droop Droop makes makes stable stable (d) (d) All All of the the abov abovee 9. Mark the correct statement regarding ass flow rate (a) Proportional to pressure pressure & inversely proportional to temperature temperature (b) Proporti Proportional onal to pressu pressure re & temperat temperature ure (c) Proportional to temperature temperature & inversely inversely proportional to pressure pressure (d) Proportional to temperature temperature & inversely inversely proportional proportional to square square root to temperature temperature 10. In modern APU (a) Load contro controll valve can can be adjuste adjusted d only after after shut shut down (b) Load control control valve valve works works in conjunctio conjunction n of surge valve valve (c) Clockwis Clockwisee rotation rotation of trimmin trimming g means increa increasing sing (d) (d) All All of the the abov abovee Answers: 1- b, 2- d, 3 - a, 4 - d, 5 - a, 6 - c, 7 - b, 8 – d, 9 – d, 10 – b.
11. Compressure blade is loose fit due to (a) Reduce Reduce vibra vibratio tional nal stres stresss (b) (b) Ease Ease of of remo remova vall
(c) Tempe Temperat rature ure compens compensati ation on (d) (d) All All of abov abovee 12. If EPR reads 2.4 then turbine discharge pressure is 2.4 times of (a) Inlet Inlet stat static ic pre pressu ssure re (b) Inlet Inlet ram pressu pressure re (c) (c) Ambi Ambien entt press pressur uree (d) Compressu Compressure re inlet inlet total total press pressure ure 13. Last chance filter in the oil system screen type (a) Cleared Cleared during during engine engine overhaul overhaul (b) Preve Prevent nt clogg clogging ing of of jet jet (c) Cleaner Cleaner during during 100 hrs inspec inspection tion (d) Both oth 1 & 2 14. Engine preservation depends on (a) Times Times remain remainss inacti inactive ve (b) Durati Duration on of preserv preservati ation on (c) Depen Depends ds on engin enginee rotati rotation on (d) (d) All All of the the abov abovee
15. Mark correct statement regarding double entry centrifugal compressor (a) Preve Prevent nt tip tip veloci velocity ty loss loss (b) Air entry entry from both both side side of comrpe comrpessure ssure (c) Requir Required ed big inle inlett chambe chamber r (d) (d) All All of the the abov abovee 16. After burner thrust augmentation (a) Thrust Thrust of basic basic engine engine can can be increa increased sed (b) Thrust increase increase by after after burner for take off off climb for military military aircraft aircraft (c) Both Both 1 & 2 are are corre correct ct (d) (d) None None of of the the abov abovee 17. If JPT is high then water is injected in (a) Inlet (b) (b) Diff Diffus user er (c) Both (d) (d) Comb Combus usti tion on
18. If water is injected in the diffuser (a) Mass flow increase increased d in entire entire engine engine (b) Less pr. pr. & temp drop drop in turbine turbine hence hence more more pr. in tail tail (c) ------------------------------------------------------------(d) (d) All All are are corr correc ectt 19. I water in injected in the inlet and diffusers (a) N1 shif shiftt towar towards ds surg surgee (b) N1 shif shiftt away away surge surge (c) N2 shift shift away away surge surge (d) Both Both N1 & N2 away away surge surge 20. Variable propelling nozzle is used due reduce TSEC
(a) (a) (b) (b) (c) (c) (d) (d)
By pass pass engi engine ne Afte Afterr bur burne ner r Wate Wa terr inje inject ctio ion n All All of abov abovee
21. Velocity in combustion chamber is reduced (a) Increa Increased sed static static pr (b) (b) Ease Ease of of burn burnin ing g (c) -------------------------------------(d) -------------------------------------22. Stable combustion means (a) (a) Low Low emis emissi sion on (b) Combusti Combustion on alighted alighted over long long range range (c) As 1 & 2 (d) ------------------------------------------------------------------------------23. In can annular liner (a) (a) Cont Contin inue uess shrou shroud d (b) Circul Circular ar & outer outer (c) Inner Inner & cyl cylind indric rical al (d) As 2 & 3 Answers: 11 – d, 12 – d, 13 – d, 14 – d, 15 – d, 16 – c, 17 – a, 18 – b, 19 – c, 20 – b, 21 – b, 22 – c, 23 – c.
24. Mark incorrect statement regarding combustion chamber drain valve (a) Mechanica Mechanically lly operat operation ion by spring spring force force (b) Failure Failure of of valve valve gives gives false false start start (c) Locate Located d in LH or or RH side side bott bottom om (d) (d) None None of of the the abov abovee 25. Canted vanes in the first few stage of compressor (a) (a) Incr Increa ease se press pressur uree (b) Increa Increase se veloci velocity ty (c) Increa Increase se tem temper peratu ature re (d) Reduce Reduce boundar boundary y layer layer separa separation tion 26. Knife edge (profile) blade (a) We Wears ars & sets sets tip tip cler cleranc ancee (b) Used in supersonic supersonic aircraft aircraft (c) (c) Is not not used used (d) Used Used in turb turbine ine blade blade 27. Repair of compressure or fan blade is called (a) Grind inding ing (b) (b) Brin Brinel elli ling ng (c) Galli lling (d) (d) Blen Blendi ding ng
28. Balancing of compressure (a) Indivi Individua duall stage stage is balanc balanced ed (b) As a unit unit balanc balanced ed (c) Both oth 1 & 2 (d) (d) Not Not requ requir ired ed 29. Turbine blade design is based on (a) Corros Corrosion ion resist resistanc ancee (b) Creep (c) Fatigue Fatigue & vibra vibration tion resistan resistance ce (d) Both oth 2 & 3 30. Fatigue stress causes (a) Elong Elongati ation on of blade blade (b) (b) Crac Crack k in LE & TE TE (c) (c) Chan Change ge of shap shapee (d) (d) All All of abov abovee
31. Mark current statement regarding radial inflow turbine (a) Air enters enters at eye eye & leaves leaves at radial radial outwa outward rd (b) Used Used in in big big engine engine (c) Air enters enters at periphe peripheral ral nozzle nozzle & flows radial radial inward inward (d) As 2 & 3 32. Function of NGV is (a) (a) Conv Conver ertt PE PE to to KE KE (b) (b) Conv Conver ertt KE to to PE (c) Directs Directs air air perpen perpendicul dicular ar to to bucket bucket (d) As 1 & 3 33. In pure turbojet engine temperature drop across turbine is (a) Same Same as compre compresso ssor r (b) About About same same as comp compres ressor sor (c) Higher Higher than compr compressor essor very very low low than compre compressor ssor (d) Very Very low low than than compre compresso ssor r 34. For load balancing in the turbine rear stages (a) More turbine turbine area area is required required (b) More More length length is is requir required ed (c) Less turbine turbine area is required required (d) As 1 & 2 35. If exhaust nozzle area is decreased (a) (a) CDP CDP inc incre reas ases es (b) (b) CDP CDP decr decrea ease sess (c) (c) SFC SFC decr decrea ease sess (d) As 1 & 3 36. What component prevent stall during low speed ground operation (a) (a) Blee Bleed d val valve ve (b) (b) P & D Valv Valvee
(c) (c) Choc Chock k Val Valve ve (d) As 1 & 2
Answers: 24 – c, 25 – d, 26 – a, 27 – d, 28 – c, 29 – d, 30 – b, 31 – d, 32 – d, 33 – b, 34 – a, 36 – a.
37. During starting starter & fuel flow are ok, but hung start cuase is (a) (a) CDP CDP sen senso sorr los losss (b) CIT los losss (c) (c) -----------------(d) -----------------------------------------38. Mark correct statement (a) Engine Engine running running at high RPM RPM & CDP lost lost then stabiliz stabilizee at idle (b) Engine running at idle RPM RPM & CDP CDP lost then then stabilize stabilize at high RPM (c) CDP lost lost during during starting starting it it is a hung hung start start (d) (d) All All are are corr correc ectt 39. Minimum fuel flow is critical (a) (a) Acce Accele lera rati tion on (b) (b) Dece Decele lera rati tion on (c) Idle (d) (d) Grou Ground nd run run 40. Which component is not installed in the engine? (a) Fuel uel pum pump p (b) FCOC (c) Filter (d) (d) Boos Boostt pum pump p 41. Deareator is located in (a) Scave Scavenge nge sub system system (b) Press Pressure ure sub syste system m (c) (c) Inle Inlett of the the pump pump (d) Oil tan tank k 42. After engine shut down oil found in the exhaust (a) (a) Seal Seal fail failur uree (b) Bearin Bearing g seal seal fail failure ure (c) (c) Repl Replac acee eng engin inee (d) Air pressuriz pressurization ation seal failure failure 43. Air tight seal is (a) (a) Carb Carbon on seal seal (b) (b) Ring Ring seal seal (c) (c) Mult Multii grov grovee seal seal (d) (d) Thre Thread aded ed sea seall
44. Mark correct statement (a) Pressure Pressure pump pump capacit capacity y is scaveng scavengee pump (b) Scavenge Scavenge pump pump capacity capacity is is more pressur pressuree pump (c) Both Both pum pumps ps capaci capacity ty (d) As 3 & both both are located located in oil syste system m 45. Mg is found in SOAP analysis then failure is (a) Gear (b) Gear box box (c) Bear earing ing (d) (d) Bear Bearin ing g shaf shaftt 46. Oil SOAP analysis then failure is (a) Pin point point impen impendin ding g failure failure (b) Take sample sample for for entire entire engine engine life (c) First First sample sample gives food analysis analysis (d) As 1 & 2 47. Property of lubricating oil is (a) (a) High High fla flash sh poi point nt (b) (b) Low Low flas flash h poin pointt (c) (c) High High pore pore poin pointt (d) Low viscos viscosity ity index index 48. Synthetic oil is used in turbojet engine (a) Corros Corrosion ion resist resistanc ancee (b) Low carb carbon on / wax form formati ation on (c) High High temper temperatu ature re operat operation ion (d) (d) All All the the abov abovee 49. Input to hydro-mechanical FCU (a) Burner Burner pressure pressure compre compressure ssure inlet inlet pressure pressure EGT EGT (b) Burner Burner pressure pressure compressu compressure re inlet pressure pressure,, RPM (c) ---------------------------------------------------------------------------------------------------------------(d) ---------------------------------------------------------------------------------------------------------------Answers: 37 – b, 38 – c, 39 – b, 40 – d, 41 – d, 42 – d, 43 – c, 44 – b, 45 – b, 46 – d, 47 – a, 48 – d, 49 – b.
50. In part EEC system (a) Control Control till till part thrott throttle le and then then switch switch off. off. (b) ------------------------------------------------------------------------------------------------------(c) ----------------------------------------------------------------------------------------------(d) (d) It is is like like FAD FADEC EC 51. In supervisory EEC
(a) (a) (b) (c) (c) (d)
Deve Develo lops ps comm comman and d Control Control standar standard d hydro-mech hydro-mechanic anical al system system Cont Contro roll valv valvee As 1 & 2
52. Acceleration & deceleration control is (a) (a) Flam Flam blow blow out out (b) To preven preventt over over flow flow (c) (c) For For max max spee speed d (d) --------------------------------------------53. High power to weight ratio is in which starter (a) (a) Elec Electr tric ic start starter er (b) Starte Starterr gene generat rator or (c) Air Air turb turbine ine starte starter r (d) Pawl Pawl & ratc ratchet het star starter ter 54. White repair AME increased length of thermo-couple (a) Over ver re read (b) (b) Unde Underr rea read d (c) No eff effeect (d) Over read at hi hi temper temperatur aturee 55. During feathering pitch angle (a) (a) Cour Course se & hig highe her r (b) (b) Low Low pitc pitch h (c) Course (d) (d) Nega Negati tive ve 56. Propeller lock LP solenoid (a) --------------------------------(b) --------------------------------(c) --------------------------------(d) ---------------------------------
57. EGT gauge yellow amber arc (a) Maximum Maximum continu continues es to maxim maximum um permis permissible sible (b) Minim Minimum um to to cont continu inuee (c) Maxi aximum mum (d) As 1 & 2 58. Torque is measured by (a) (a) Heli Helica call gear gear (b) (b) Rack Rack & pin pinio ion n (c) Spur pur gea gear r (d) (d) Plan Planet etar ary y gear gear 59. As altitude increases stall margin (a) Reinol Reinold d No. No. Effec Effectt (b) Increase Increasess that’s why aircra aircraft ft flying flying only at high altitude altitude (c) (c) Decr Decrea ease sess (d) --------------------------------------------------------------------------------------------------------------------------------------
60. Trimble coil in ignition system (a) Connected Connected paral parallel lel to prima primary ry capaci capacitor tor (b) Connected Connected serie seriess to primar primary y capacitor capacitor (c) Not used used in in igniti ignition on syste system m (d) Used Used in star startin ting g system system Answers: 50 - , 51 – b, 52 – a, 54, b, 55 – a, a, 56 - , 57 – a, 58 – a, 59 - , 60 – a.
JET ENGINE OCT 2003
61. Shaft engine forward bearing is (a) (a) Ball Baller er bear bearin ing g (b) (b) Roll Roller er bea beari ring ng (c) 1 + is is locat locator or beari bearings ngs (d) 2 + is take takess radia radiall load load 62. MCS (a) APU generator generator frequency frequency is maintained maintained by CSD and is constant speed rated rated (b) APU does not have CSD in its operation operation and is constant speed rated (c) APU generator generator requires requires axial flow compressor compressor and is constant speed rated rated (d) Both Both B and and C are are corr correct ect 63. MCS (a) In turbo-jet turbo-jet TSFC TSFC increa increases ses as airspeed airspeed increa increases ses (b) In turbo turbo prop TSFC TSFC decreases decreases as airspeed airspeed increa increases ses (c) In turbo turbo prop TSFC TSFC increases increases as airspee airspeed d increases increases up to 450 mph (d) Both Both A and and B are are correc correctt 64. MCS (a) Temp drop through turbines turbines is greater greater than that that of temp rise through compressor (b) Temp drop through through turbine is same same as the temp rise through same same no of stages of compressor (c) Temp drop through turbine is about the same as that of temp temp rise through through compressor compressor (d) Temp drop through turbine is less that that that of temp rise through compressor compressor 65. TSFC is
(a) (b) (c) (d)
Directly Directly proportio proportional nal to the the rpm rpm Directly Directly proport proportiona ionall to the effici efficiency ency Inversel Inversely y proportio proportional nal to the the efficie efficiency ncy Directly Directly proport proportiona ionall to the compress compressor or ratio
66. Primary function of inlet duct is (a) To convert kinetic energy energy of rapidly rapidly moving air stream into ram pressure rise (b) To convert convert potential energy into into kinetic kinetic energy inside the duct (c) To convert convert potential potential energy energy into ram pressure pressure rise rise inside the duct duct (d) To convert convert kinetic energy into into potential energy outside outside the duct 67.Compressor inlet screens (a) Are found found in rotorcraft rotorcraft TPE and and ground turbine turbine install installation ationss (b) Are sued sued mostly mostly in axial axial flow flow turbojet turbojet engine enginess (c) A + have have problems problems of of icing icing and fatig fatigue ue failure failure (d) B + if fitted they they may be be located either either the inlet or the the compressor inlet 68. Two shaft whose axes are at an angle to one another but in the same plane to gear used (a) (a) Beve Bevell gear gear (b) Spira Spirall beve bevell gear gear (c) Spur pur gea gear r (d) (d) Heli Helica call gea gear r 69. Prime requirement for stator anes is (RR31) (a) Corros Corrosion ion resist resistanc ancee (b) Fatig Fatigue ue streng strength th (c) Smooth Smooth surfac surfacee finis finish h (d) (d) Heat Heat resi resist stan ance ce Answers: 61 – d, 62 – a, 63 – d, 64 – c, 65 – c, 66 – a, 67 – c, 68 – b, 69 – b.
70. Function of P & D valve is (a) (a) Flow Flow divi divide der r (b) Dumping Dumping fuel fuel after after engine engine shut down (c) Fuel Fuel press pressure ure contro controll (d) (d) All All of the the abov abovee 71. Propulsive efficiency of high by pass turbofan is high due to (a) (a) Same Same leng length th (b) (b) Smal Smalll tur turbi bine ne (c) Small mall dia (d) (d) All All corr correc ectt 72. AME’s knows OAT is significantly shifted but TGT is same at ground. In the high power run every thing is normal then snag is (a) (a) CIT CIT sy system stem (b) (b) CPP CPP sys syste tem m (c) FCU temperat temperature ure compensat compensator or (d) Thrott Throttle le missri missrig g 73. Trimming means (a) Adjust Adjusting ingidl idlee & max powe power r (b) Adjust Adjusting ing exhau exhaust st nozzle nozzle (c) Adjusting Adjusting throttle throttle for full full forwa forward rd (d) (d) All All of the the abov abovee 75. There is a problem in the turbine then (a) Vibratio Vibration n increase increasess with RPM RPM increa increases ses (b) Vibratio Vibration n decreases decreases with with RPM RPM increases increases (c) No chan change ge of of vibr vibrati ation on (d) (d) None None of of the the abov abovee 76. Ignition plug correct statement (Compare to PE) (a) Wide ider gap gap (b) Less fouli fouling ng problem problem due due to high high spark spark (c) -----------------------------------------------------------------------------------(d) As 1 & 2 77. Propeller feather (a) Elect Electric ric cut out out swit switch ch (b) ------------------------------------------------(c) ------------------------------------------------(d) -------------------------------------------------
78. Part throttle (a) Throttle Throttle movement movement less less than than full forward forward (b) ----------------------------------------------------------------------------------------------(c) ----------------------------------------------------------------------------------------
(d) ----------------------------------------------------------------------------------------------79. ----------------------------------------------------------------------------------------------------(a) -------------------------------------------------------------------------------------(b) -----------------------------------------------------------------------------------(c) -------------------------------------------------------------------------------------(d) -------------------------------------------------------------------------------------Answers: 70 – d, 71 – a, 72 – a, 73 – a, 74 – a, a, 75 – a, 76 – d, 77 - , 78 - , 79 - , 80 - .
1. Engine performance check needed (a) To see see mechanic mechanical al integrit integrity y of the the engine engine (b) Instru Instrumen mentt check check (c) (c) Powe Powerr che check ck (d) (d) All All are are corr correc ectt 2. Modern aircraft engines (a) Have many drain holes at different different location to to drain volatile volatile fluid used inengine (b) There There are no such such drain drain holes holes provide provided d (c) FCOC FCOC has has provisi provision on for for draini draining ng (d) Both Both A and and C are are correc correctt 3. MCS (a) Compresso Compressorr and turbine discs discs are forged forged by powder powder metallurgy metallurgy
(b) Compresso Compressorr blades blades and vanes are are generally generally cast cast (c) Turbine Turbine blades blades and and vanes are are made by lost wax wax method method (d) (d) All All are are corr correc ectt 4. Run down time is (RR 261) (a) Time taken taken by the engine to come come to rest after closing closing the shut off valve (b) It gives gives indication indication of wear wear or rubbing rubbing inside inside the engine engine (c) Wind velocit velocity y and direction direction may may affect affect the RDT of of an engine (d) (d) All All are are corr correc ectt 5. Sound suppressors used in gas turbine engine to (a) (a) Redu Reduce ce ener energy gy (b) Increa Increases ses freque frequency ncy (c) (c) Incr Increa ease se edd eddie iess (d) (d) All All are are corr correc ectt 6. MCS regarding jet cal analyzer (a) Used to check check EG thermocoupl thermocouplee during engine engine run or without without running running (b) Used to check check continuity and resistance resistance of the EGT EGT circuit circuit during engine run only only (c) Used to to check check % rpm. rpm. During During engine engine run run only (d) Both Both B and and C are are corr correct ect 7. Oil pressure indicating system is (a) Auto uto sy sync (b) (b) Ther Thermo moco coup uple le (c) (c) Resi Resist stan ance ce (d) (d) Sync Synchr hron onou ouss
8. Major disadvantage of air turbine starter is (a) It produc produces es low low torq torque ue (b) Requires Requires high volume volume of airflow airflow (c) Comple Complex x cons constr truct uction ion (d) Limit Limited ed to smal smalll engine engine 9. MCS (a) (b) (c) (d) (d)
Igniter plugs have problem of corrosion corrosion of case, and after prolonged use it get eroded The audible test for proper proper ignition check is not not possible in synchronous synchronous ignition Iridium Iridium inserts inserts are are placed placed in the tip to prolong prolong its lift lift All All are are corr correc ectt
Answer: 1 – c, 2 – d, 3 – d, 4 – d, 5 – b, 6 – c, 7 – a, 8 – b, 9 – d.
10. Engine inference (a) Nozzle Nozzle diaphragm diaphragm area area is measured measured at the exit exit of the vanes vanes (b) Total outlet area measured is is the sum of all areas of the passages passages between the the vanes (c) Nozzle Nozzle area effec effects ts the effici efficiency ency of the the engine engine (d) (d) All All are are corr correc ectt 11. Hydromantic pitch propeller (a) Is constant constant speed speed counter counter weight weight type type propell propeller er (b) As in A also used used for full featherin feathering g (c) As in B also used used for for reversi reversing ng operatio operation n (d) As in C also also used for for maneuver maneuverable able pitch pitch change change 12. Oil found in gas path (a) Inoper Inoperati ative ve scaven scavenge ge pump pump (b) Fuel Fuel leak leak in oil sys system tem (c) (c) Low Low vent vent pre press ssur uree (d) None None of the the above above is corr correct ect 13. When water is injected in inlet alone (a) N1 will will move move away away from from stall stall (b) N2 will will move away away from from stall stall (c) N1 will will move move towa towards rds stal stalll (d) Both N1 N1 and N2 N2 will will move away from stall stall 14. Trimming is carried out (a) To set idle idle to max rpm (b) To adjust adjust acceler acceleration ation and and decelera deceleration tion (c) To limit limit exhaust exhaust gas gas temper temperatur aturee (d) To set set compress compressor or bleed bleed valve valve opening opening 15. In centrifugal compressor engine thrust is determined by (a) RPM (b) EPR (c) EGT (d) TORQUE
16. Increasing NGV area will cause (a) (a) N1 incr increa ease se (b) (b) N1 decr decrea ease se (c) (c) TSFC TSFC decr decrea ease se (d) (d) N1 no chan change ge
17. For a given compressor rpm if airflow increase (a) Compressi Compression on ratio ratio increases increases surge surge margin margin decreases decreases (b) Compressi Compression on ratio increas increases es surge margin margin increases increases (c) Compressi Compression on ratio ratio decreases decreases surge surge margin margin increases increases (d) Compressi Compression on ratio increas increases es surge margin margin increases increases 18. If bypass valve is fitted across the metering valve, and P1 is inlet pressure and P2 is outlet pressure then constant fuel pressure differential is depends on (Tr.273) (a) P2 – P2 P2 (b) (b) Orif Orific icee are areaa (c) (c) Mete Meteri ring ng valv valvee (d) (d) Bypa Bypass ss valv valvee Answers: 10 – d, 11 - , d, 12 – a, 13 – a, 14 – a, 15 – a, 16 - , 17 – a, 18 – d.
19. Two internal sections of an engine are subjected to different air per seel to be used (a) (a) Thre Thread ad seal seal (b) (b) Ring Ring seal seal (c) (c) Mult Multii groo groove ved d seal seal (d) (d) Carb Carbon on sea seall 20. The afterburner engine liner is perforated (a) Which Which is cooled cooled by secondary secondary air (b) (b) Lead Leadss to scre screec ech h (c) (c) A and and B are are corr correc ectt (d) (d) None None of of the the abov abovee 21. In a hydro mechanical torque meter if the temperature of oil is increased causes (a) High High torque torque readi reading ng (b) Low torque torque readin reading g (c) No cha chan nge (d) (d) Any Any of the the abo above ve 22. Most prevalent condition for icing is (a) High High rpm rpm low low airs airspee peed d (b) High High rpm rpm high high airsp airspeed eed (c) Low rpm low airspe airspeed ed (d) High High rpm rpm high high veloc velocity ity 23. MCS (a) Electrical heaters are mostly preferred preferred than pneumatic heating heating for anti-icing anti-icing system system (b) Isopropyl alcohol or phosphate compounds compounds are used for deicing system system (c) Anti icing icing heating heating is command commanded ed through through cyclic cyclic timers timers (d) (d) None None of of the the abov abovee 24. Turbo shaft with free turbine, its speed is controlled by (a) (a) Ng gove govern rnor or (b) (b) Nf gov gover erno nor r (c) (c) Idle Idle gove govern rnor or (d) Not cont control rolled led by gover governor nor 25. The oil system used by VTOL engine is (a) Full ull flo flow w (b) Hot tank ank (c) Total Total loss loss (expa (expanda ndable ble)) (d) Press Pressure ure reli relief ef valve valve
26. In full flow oil system quantity of oil flow is determined by (a) Take off (b) Cruise (c) (c) Grou Ground nd idle idle (d) (d) All All rpm rpm rang rangee 27. In test house first and last test carried out after overhaul is (a) (a) Vibr Vibrat atio ion n surve survey y (b) (b) Hot Hot air air lea leak k (c) Engine Engine power power settin setting g
Answers: 19 – c, c, 20 – a, 21 – b, 22 – b, 23 – d, 24 - , 25 – c, 26 – d, d, 27 - .
28. Factory ignition depends upon (a) Volati Volatilit lity y of fuel fuel (b) Specif Specific ic gravit gravity y (c) (c) Visc Viscos osit ity y (d) As in A atomiz atomizati ation on 29. MCS (a) Turbojet Turbojet engines engines used annular annular combusti combustion on for shorter shorter length length (b) Turbojet engines used reverse flow flow combustion combustion for shorter length length (c) Turbofan Turbofan engines engines give give best best perform performance ance (d) B and and C are are correc correctt 30. Compression in an axial flow engine is (a) (a) Isot Isothe herm rmal al (b) (b) Adia Adiaba bati ticc (c) (c) Isom Isomet etri ricc (d) (d) Isob Isobat atic ic 31. Decreasing nozzle area will cause (a) Pt7 up* (b) Pt7 dow down
(c) Tt7 down own (d) (d) No chan change ge 32. Part time fuel control (a) Used Used for for part part powe powerr trim trim (b) Operates Operates in adverse adverse condit condition ion (c) Operates like like hydro mechanical mechanical fcu fcu up to max. max. Power then amplifier amplifier takes care (d) Operat Operates es like like FADEC FADEC 33. Last chance filter is used in (a) (a) Oil Oil sys syste tem m (b) (b) Fuel Fuel sys syste tem m (c) Oil tank ank (d) (d) Deai Deaira rato tor r 34. If Pt2 is partially blocked by ice formation (a) EPR EPR will will increa increase se (b) EPR EPR wil willl decr decreas easee (c) EPR EPR wil willl flua fluatua tuate te (d) EPR EPR wil willl not not chang changee
35. More than one weld is not carried out in deicing element because (a) Increase Increasess circuit circuit resista resistance nce of eleme element nt (b) Decrease Decreasess circuit circuit resistan resistance ce of element element (c) It will will dama damage ge the the elemen elementt (d) All All the above above may may happe happen n 36. The function of selector valve is post exit thrust reverse is (a) It gives gives comman command d for reverse reverse operati operation on (b) It selects selects the actuator actuator valve valve to operate operate thrust thrust reverse reverse (c) T operates operates the hydrauli hydraulicc valve to slow and deploy deploy thrust thrust reverse reverse (d) (d) None None of of the the abov abovee Answers: 28 – d, 29 – d, 30 – b, 31 – a, 32 – c, 33 – a, 34 – a, 35 - b 36 – c.
37. Most commonly used oil in gas turbine engine is (a) (a) Petr Petrol oleu eum m (b) (b) Akyl Akyl dies diesta tar r (c) (c) Poly Polyes este ter r (d) Mine ineral ral 38. Mark INCORRECT statement (a) Screen Screen type type filter filter is used used in low pressur pressuree (b) Cartridg Cartridgee type filter filter is used in in low pressur pressuree (c) Screen Screen disk type type filter filter is used used in low low pressure pressure (d) Cone shaped shaped filter filter element element is used used in screen screen type filter filter 39. In turboprop power lever is interconnected to (a) (a) Thro Thrott ttle le leve lever r (b) (b) Prop Propel elle lerr lever lever (c) (c) Cond Condit itio ion n leve lever r (d) (d) Gove Govern rnor or 40. MCS (a) For a given given torque weight weight of starter starter generator generator is less less than air turbine starter starter (b) Starter Starter generat generator or windings windings are are separate separate (c) Duty cycle cycle of starter starter generator generator is more critical than than air turbine turbine starter (d) (d) None None of of the the abov abovee 41. In turboprop during starting the positions of levers are (a) Throttle Throttle lever lever at idle idle and propeller propeller lever lever at high pitch pitch (b) Throttle lever lever at idle and propeller propeller lever at nay position from high to low low pitch (c) Propelle Propellerr lever at at idle thrott throttle le lever lever at idle idle (d) Throttle lever at idle and propeller lever at low pitch pitch setting 42. If oil quantity is increased cause is (a) Scave Scavenge nge pump pump fail failure ure (b) (b) Food Food facu facult lty y (c) Bearin Bearing g press pressure ure loss loss (d) (d) All All of abov abovee 43. During starting satisfactory condition for combustion is (a) Low press pressure, ure, high temp, temp, low veloc velocity ity (b) High pressu pressure, re, high high temp, temp, high high velocity velocity (c) Low press pressure, ure, high temp, temp, high velocity velocity (d) High pressu pressure, re, high high temp, temp, low velocity velocity
44. Gradual darkening of oil is due to (a) Degra Degraded ded oil is used used (b) Inhibitor Inhibitor perfor performing ming its functi function on properly properly (c) Excess Excessive ive air air leak leak in to the oil oil (d) (d) All All are are corr correc ectt 45. MCS (a) Oil bypas bypasss valve valve is instal installed led at at inlet inlet (b) Oil flow flow through through passages passages depend depend on the operati operation on (c) If problem problem occurs occurs fuel will will flow flow into into oil (d) (d) All All are are corr correc ectt Answers: 37 – c, 38 – c, 39 – b, 40 – b, 41 – d, 42 – b, 43 – d, 44 – b, 45 – c.
46. Thrust of turbofan measured in test cell by (a) EPR (b) EPR/NI (c) (c) Torq Torque ue met meter er (d) (d) Thru Thrust st mete meter r
47. In post exit thrust reverse is deployed by (a) (a) Isol Isolat ator or valv valvee (b) (b) Sele Select ctor or val valve ve (c) (c) Shut Shut off off val valve ve (d) (d) Shut Shuttl tlee val valve ve 48. In a (a) (b) (b) (c) (d) (d)
constant displacement pump the output volume is 10 gph it actually Deliv livery ery Disp Displa lace ceme ment nt Volume Volumetri tricc effici efficienc ency y All All are are corr correc ectt
49. MCS (a) The seal seal which rides rides on highly highly polished polished surface surface is carbon carbon seal seal (b) Carbon Carbon seals are are used in vent vent pressuriza pressurization tion system system (c) Both Both A and and B are are corre correct ct (d) None None of the the above above is corr correct ect 50. In reheat engine with reheat operation (a) (a) Dry Dry EGT EGT is high high (b) (b) Dry Dry EGT EGT is low low (c) No effect effect on EGT EGT as it remain remain same same (d) (d) We Wett EGT EGT is is high high 51. Safety feature incorporated in air turbine starter (a) Starter Starter shaft shaft with shear shear neck section section shears shears off when over speeded speeded (b) Starter turbine gets gets chocked in case of air inlet valve valve failure failure (c) Any malfunction malfunction occurs occurs magnetic magnetic chip detector inspection inspection is carried out (d) (d) All All are are corr correc ectt 52. Most important property of turbine blades (a) Corros Corrosion ion resist resistanc ancee (b) Creep Creep resist resistanc ancee (c) Vibra Vibratio tion n resis resistan tance ce (d) Fatigu tiguee
53. Property required in NGV (a) Corros Corrosion ion resist resistanc ancee (b) (b) Heat Heat resi resist stan ance ce (c) (c) Cree Creep p resis resista tanc ncee (d) Fatig Fatigue ue resist resistanc ancee 54. Prist used in fuel for (a) (a) Anti Anti-i -ici cing ng (b) (b) Anti Anti-b -bio ioci cida dall (c) (c) A and and B are are corr correc ectt (d) (d) Anti Antico corr rros osiv ivee
Answers: 46 – d, 47 – b, 48 – b, 49 – a, 50 – c, 51 – d, 52 – b 53 – b.
55. P & D valve senses (a) Elect Electric rical al signal signal (b) Rpm (c) Inter Inter stage stage pum pump p pressu pressure re (d) (d) All All of abov abovee 56. Function of NGV (a) To increases increases the pressur pressuree at its outlet as per Bernoull Bernoulli’s i’s theorem theorem (b) To deflec deflectt the gases gases at desired desired angle angle (c) As in B to increa increase se the velocity velocity of of gases gases at its outlet outlet (d) (d) None None of of the the abov abovee 57. If any fault occurs in FCOC (a) Oil Oil will will flow flow into into fuel fuel (b) Fuel Fuel will will flow flow into into oil (c) Fuel Fuel quantit quantity y will will increas increasee (d) (d) None None of of the the abov abovee 58. Water methanol is injected at inlet of compressor (a) Increase Increasess mass airfl airflow ow through through whole whole engine engine (b) Increa Increases ses the the fuel fuel flow flow (c) Both Both A and and B are are corre correct ct (d) (d) None None of of the the abov abovee 59. Output of gear rotor pump
(a) Proportional to the missing missing tooth multiplied by no. of teeths on outer outer gear 60. Breather pressurization system (a) Keeps Keeps the constant constant pressure pressure in the sump sump for positi positive ve flow of oil oil (b) Ensures Ensures positive positive flow flow of oil to the bearin bearing g chambers chambers 61. Angle of blades during starting of turboprop (a) Fine pitch pitch so that that minimu minimum m resistanc resistancee on blades blades (b) Coarse Coarse pitch so that that minimum minimum resistan resistance ce on blades blades (c) Any angle angle so so that EGT should should not not exceed exceed limit limit (d) (d) None None of of the the abov abovee Answers: 55 – c, 56 – c, 57 – a, 58 – a, 59 – a, 60 – a, 61
JET ENGINE (GAS TURBINE ENGINE) (OCT 2000) ESSAY LIST & EXPLAIN NON DESIGN FACTORS AFFECTING THRUST LIST FIVE ALLOYS THAT ARE USED IN THE CONSTRUCTION OF GAS TURBINE ENGINE. DE? PROPERTIES OF EACH THAT MAKE IT ESIRABLE FOR USE IN SPECIFIC LOCATIONS IN THE DRAW BLOCK DIAGRAM & EXPLAIN A TYPICAL FUEL SYSTEM DESCRIBE THE GAS FLOW THR A TYPICAL REVERSE FLOW ANNULAR COMBUSTION CHAMBER REQUIREMENTS OF GOOD THRUST REVERSER WHAT DO YOU UNDERSTAND ABOUT COMPRESSOR STALL LIST THE METHODS TO PREVENT COMPRESSOR STALL & EXPLAIN ONE ADVANTAGES & DISADVANGES OF AXIAL & CENTRIFUGAL COMPRESSOR & APPLICATION CHARACTERISTICS ADVANTAGES & DISADVANTAGES OF 1) TURBOPROP 2) TURBOFAN 3) TURBOJET EXPLAIN WHAT IS MEANT BY PERFORMANCE MONITORING & DISCUSS IT’S IMPLICATION IMPROVE RELIABILITY OF ENGINE PROCEDURE FOR LONG – TERM STORAGE (PRESERVATION) OF ENGINE OBJECTIVE 1. A large jet engine handles 100 lb. Sec of air the velocity of this air at the jet nozzle is 659 mph what is the thrust of the engine F MA F = (Wa / g) A = (100/32.2) (659*1.467) = 3002 LB **(initial speed = 0) Mark correct statement 1. What the gross thrust is computed (a) The velocity of the air coming coming into the engine engine due to velocity velocity of airplane is disregarded disregarded
(b) The loss in thrust thrust involved in taking air in at at the front of the engine is known known as ram drag, drag, Net thrust is then gross thrust minus ram drag (c) (c) As in (1) (1) & (2) (2) (d) (d) None None of of the the abov abovee 2. The complete formula for a turbojet engine with a choked nozzle is Fn = (Wa/g) (v2-v1) + (Wf/g) Vf + Aj (Pj-Pam)* 3. MCS 1. The rated net thrust of any engine is determined by how much the forward thrust forces exceed the rearward forces 4. MCS 1. At higher altitude pressure continues to drop sharply W.R.T temperature resulting Sharp drop in thrust 5. MCS 1. Brayton cycle called open cycle 6. Ram recovery point is that 1. A/c speed, which the ram pressure rise is equal to friction pressure losses 7. Engine mfr rate their engine by Bell month inlet duct 8. British thermal unit is a standard measure of energy defined as the amount of energy reqd to raise the temperature of 1 pound of water to 1-degree faranhit at (a) Consta Constant nt pressu pressure re (b) (b) Cons Consta tant nt volu volume me (c) (c) Cons Consta tant nt mass mass (d) (d) None None of of the the abov abovee 9. Can annular combustion chamber (a) Greater Greater structur structural al stability stability & lower lower pressure pressure drop drop (b) Outer Outer case made made to slide slide for line line inspecti inspection on (c) As in 1 & 2 (d) (d) None None of of the the abov abovee 10. A unique cooling concept reduces cooling air requirements by 50% & decrease weight by 20% the combustor is (a) Annu nnular lar (b) (b) Can Can annu annula lar r (c) Can type (d) Fin wall 11. Noise protection device is required (a) Frequ Frequenc ency y up up to to 100d 100db b (b) As in 1 with with ear ear plug plug (c) Frequ Frequenc ency y up up to to 160d 160db b (d) As in 2 with with ear ear prote protecto ctor r 12. Water injection coolant freezing point Any increase in back pressure from exhaust nozzle affects (a) R.P.M (b) Compre Compresso ssorr stall stall (c) E.G.T
(d) (d) All All abov abovee
13. After burners spray bars Turbine vane/blade cooling figure (a) Convection (b) Impingement (c) Film (d) All above 14. In fuel flow control one of the method is (a) Keeping Keeping pr. Drop Drop constant constant & vary varying ing orifice orifice area area 15. Droop can be reduced (a) By using using weak weaker er spri spring ng (b) Marking Marking orifice orifice openin opening g more radially radially (c) Using Using by increasing increasing the press pressure ure drop drop (d) (d) All All abov abovee 16. For the fuel pump containing two stages the possible connections are (a) Series (b) (b) Para Parall llel el (c) (c) Seri Series es-p -par aral alle lell (d) (d) All All abov abovee 17. Fuel passage drilled at right angle (a) Fuel is discharged discharged with a swirling swirling motion in order to provide provide low axial air air velocity & high flame speed (b) Fuel is discharged discharged with a swirling swirling motion in order to provide provide high axial air air velocity & low flame speed (c) As in air air shroud surrounding surrounding the nozzle cools the nozzle tip & improves improves combustion combustion by (d) As in reduce reduce the accumul accumulation ation of carbon carbon deposits deposits on the face face 18. High oil consumption (a) Defec Defectiv tivee scaven scavenge ge pump pump (b) High High sump sump pressu pressure re (c) As in 1 & 2 19. High intensity means A lethal charge is present Identify the figure of igniter plug Low voltage shunted surface gap An turbine starter not reaching cut-off self accelerating speed reason (a) Rotary Rotary switch switch in in regulato regulatorr v/v is is not adjuste adjusted d (b) Shear Shear off drive drive shaft shaft (c) As in 1 & 2
20. Trend monitoring analysis (plot of EGT, N1, N2, VIB, F/F vs TIME) (a) 1st stage NGV failure (b) 13th stage bleed v/v cracked (c) Turbin Turbinee case case separa separatio tion n
(d) (d) All All the the abov abovee 21. SOAP TEST (a) Pin point point the the impend impending ing failure failure (b) Used Used for trend trend moni monitor toring ing (c) As in 1 & 2 22. Gap between THUMB & FOREFINGER denotes Slight adjustment Starting sequence of engine is Starter ignition fuel 23. Identify seal in figure (a) (a) Laby Labyri rint nth h seal seal (b) Carbon Carbon rubbin rubbing g seal seal (c) (c) Magn Magnet etic ic seal seal 24. Helicopter uses gas turbine engine (a) Turbo Turbo shaft shaft with free turbine turbine (b) Turbo Turbo shaft shaft with with fixed fixed turbine turbine 25. Shrouded turbine tip provides (a) Long Long blad bladee thi thin n tig tig (b) Reduced Reduced distortio distortion n under under load (c) Dampe Dampen n the the vibr vibrati ation on (d) (d) All All abov abovee 26. Shingling is due to (a) (a) Comp Compre ress ssor or stal stalll (b) F.O.D (c) (c) Over Over spee speed d (d) (d) All All abov abovee
JET ENGINE GENERAL
1. Inlet guide vanes are not present in turbofan engine, in order to (a) (a) Redu Reduce ce nois noisee leve levell (b) Reduce Reduce weig weight ht of the the engine engine (c) Increa Increase se mass mass airfl airflow ow 2. Turbojet engines having axial-flow compressors have what type of rear bearing (a) Ball (b) Rolle oller r (c) (c) Tape Taper-r r-rol olle ler r (d) (d) Need Needle le-n -nos osee
3. Some high volume turboprop and turbojet engines are equipped with tow spool or split compressors. When these engines are operated at high altitude (a) Throttle must be retarded to prevent over speeding speeding of the two comp. Rotors due to low density air (b) Throttle must be retarded to prevent over speed speed of H.P rotor due to low density density air (c) L.P rotor rotor will decrease decrease in speed as compressor compressor load decreases in lower density air (d) L.P rotor rotor speed speed does does not change change with with altitude altitude 4. In a gas turbine engine firewalls are provided (a) To separa separate te the hot zone zone and the cold cold zone zone (b) To prevent the fuel leaking leaking from the fuel lines to come come from the the hot section section (c) (c) Both Both are are cor corre rect ct (d) None 5. The most modern method of cooling turbine blade and nozzle vanes is (a) Design Design of hollow hollow blades blades and and hollow hollow nozzle nozzle vanes vanes (b) Film cooling cooling of vanes vanes and blades blades (c) (c) Redu Reduci cing ng T.I T.I.T .T 6. Swirling vanes are sued in fuel nozzles (a) For rapid rapid combus combustio tion n (b) To handle handle more more fuel fuel (c) (c) To han handl dlee more more air air (d) (d) All All are are corr correc ectt 7. Ice formation on engine is (a) More More danger dangerous ous than than on on wing wing (b) Less Less danger dangerous ous than than on wing wing (c) Equally Equally danger dangero7d o7d as ice ice formatio formation n on wing wing
8. Flame out occurs in the following condition (a) Lean flame flame out low low fuel pressure pressure high high r.p.m r.p.m high altitud altitudee (b) Lean flame flame out low low fuel pressure pressure low low r.p.m, r.p.m, low altitude altitude (c) Rich flame flame out low low fuel pressure pressure low low r.p.m. r.p.m. low altitud altitudee 9. Blade twist is given (a) For consta constant nt air air flow flow along along the the length length (b) To distrib distribute ute load load along along the blade blade length length (c) To mainta maintain in constant constant outlet outlet pressure pressure (d) (d) All All of the the abov abovee 10. At high altitude (a) (a) N2-N N2-N1 1 is max maxim imum um (b) N1 rotor rotor will will rotate rotate faste fasterr than N2 N2 rotor rotor 11. In a split spool compressor turbine as aircraft altitude increases (a) L.P spool spool increase increasess in speed due to reducti reduction on in air density density (b) H.P spool spool speed decreas decreases es to compensate compensate density density reducti reduction on (c) H.P spool spool speed increase increasess to compensate compensate density density reductio reduction n (d) Both H.P H.P and L.P spool spool maintain maintain their original constant constant speed 12. For proper ignition of air/fuel mixture in the combustion chamber (a) High compressor compressor discharge pressure high inlet temperature temperature and low viscosity viscosity is ideal ideal (b) High compressor compressor discharge pressure low temperature and and low velocity velocity is ideal
13. In a combustion chamber flame out occurs if (a) There There is disturbanc disturbancee in air-flow air-flow (b) Fuel Fuel nozzle nozzle is is clogg clogged ed (c) Ignite Igniterr plug plug is is fault faulty y 14. In an axial flow turbine engine what type of rear bearing is mostly used? (a) (a) Ball Ball bea beari ring ng (b) (b) Roll Roller er bea beari ring ng (c) Taper Tapered ed roll roller er bear bearing ing 15. Fuel trimming is done in the field only? (a) To up trim trim the the engine engine (b) To compens compensate ate the the thrust thrust due to blades blades loss loss (c) To compensate compensate the thrust thrust due to contamin contamination ation of the compre compressor ssor blade blade 16. At high altitude (a) Surge Surge line moves moves up as r.p.m r.p.m.. line moves moves down (b) Surge Surge line moves moves downas downas r.p.m. r.p.m. line line moves moves up (c) Surge Surge line line moves moves up as r.p.m. r.p.m. line moves moves up (d) Surge Surge line moves moves down as as r.p.m. r.p.m. line line move move down 17. Brayton cycle is known as (a) Consta Constant nt press pressure ure cyc cycle le (b) Consta Constant nt volum volumee cycle cycle (c) Consta Constant nt mass mass cycle cycle (d) Constant Constant combusti combustion on cycle cycle 18. What would be the possible cause of a gas turbine engine to have as high EGT high fuel flow and low r.p.m. At all engine power settings? (a) Insuffici Insufficient ent electri electrical cal power power to the instant instant bus bus (b) Fuel control control out out of adjustmen adjustmentt (c) Loose Loose or corroded corroded thermoco thermocouple uple (d) Turbine Turbine damage damage of loss loss of turbine turbine effic efficiency iency 19. The speed of high pressure compressor is less than that HPT because ? (a) Turbin Turbinee has more more no no of blade bladess (b) Turbine Turbine and compr compressor essor have have same same no of blades blades (c) Turbine Turbine operat operates es at high temper temperatur atures es (d) Turbin Turbinee area area is is more more 20. During trimming at high humidity the effect on jet engine is (a) Increa Increased sed P5 and and decrea decreased sed P2 (b) Increa Increased sed engi engine ne trim trim (c) Decre Decrease ased d engin enginee trim trim (d) (d) No effe effect ct 21. Work done W by the compressor as shown when Sp is the specific heat, is expressed as (a) (a) W = Sp (T1 (T1 – T2) T2) / m (b) W = Sp. m. (T2 – T1) T1) (c) (c) W = m. m. (T2 (T2 – T1) T1) / Sp (d) (d) W = m. m. Sp Sp (T1 (T1 – T2) T2) 22. For a particular setting the compressor r.p.m. on a hot day compared to a standard day will (a) Incre ncreaase (b) (b) Decr Decrea ease se (c) (c) Rema Remain in same same
(d) Nothin Nothing g can be be said said firmly firmly 23. Noise reduction at exhaust duct (a) Changes Changes the the low frequ frequency ency to high frequ frequency ency (b) Changes Changes the high high frequenc frequency y to low frequ frequency ency (c) Decrease Decrease the the velocit velocity y of the the exhaust exhaust gases gases (d) Decrease Decrease the the pressure pressure of the the exhaust exhaust gases gases 24. The load distribution over a turbine blade as shown in the sketch is for (a) Impuls Impulsee type type blade blade (b) Reacti Reaction on type type blade blade (c) Impuls Impulsee – reactio reaction n type type blade blade (d) (d) None None of of the the abov abovee 25 Materials used in engine construction Compressor Gear box Combustion chamber Exhaust cone (a) Mg-alloy Cobalt Ti-alloy --(b) Ti alloy Mg-alloy Ni-alloy Cobalt (c) Ni-alloy Aluminum Ni-alloy Cobalt (d) C Co obalt Magnesium Ni-alloy Steel 26. A tachometer reads 100% when it is being driven at 4200 r.p.m. If the tachometer drives gear ratio is 0.428:1, what is actual speed of the compressor? 27. Mark the correct statement: Surge is associated with (a) Sharp Sharp uncoordina uncoordinated ted aircra aircraft ft maneuver maneuverss (b) Thrust Thrust rever reverse se operati operation on (c) After Afterbur burner ner oper operati ation on (d) All All of the the above above are are corre correct ct 28. Match the following in pick up and O/p and O/p signals of the following instruments (a) Thermocouple D.C voltage (b) Accelerometer Charge thermocouple d.c. voltage (c) Speed tachometer D.C signal speed tachometer – a.c. signal (d) Electronic fuel flow A.C. signal vibration pick – up – a.c. 29. If Pt2 blocks partially E.P.R. (a) (a) Incr Increa ease sess (b) (b) Decr Decrea ease sess (c) (c) Rema Remain inss the the same same (d) (d) Cons Consta tant nt 30. Low energy ignition exciter 31. Engine casing a hottest (a) Combus Combustio tion n chambe chamber r (b) (b) L.P L.P turb turbin inee (c) (c) H.P H.P tur turbi bine ne (d) Jet Jet pi pipe
32. In a chromel Alumel thermocouple instrument shown (a) (a) A is is +ve +ve and and B is –ve –ve (b) A is gree green n and B is whit whitee
(c) (c) A is is –ve –ve and and B I +ve +ve 33. In the adjoining figure, why are the curves for real and ideal conditions different? (a) Since Since air is is not treat treated ed as a compr compresse essed d gas Surge Buzz Positi Positive ve inci inciden dence ce stal stalll Negat Negative ive incid incidenc encee stall stall
Supersonic Rear Rear stage stage stall stall at at high high spee speed d front front stage stage stall stall at at high high speed speed
34. Mark the correct statement (a) Whittle Whittle combusti combustion on chamber chamber has low press pressure ure loss (b) Annular Annular combusti combustion on chamber chamber has low smoke smoke emission emission (c) Annular Annular combustion combustion has the the most optimum optimum utilizatio utilization n of space 35. Mark the correct statement regarding the cleaning of various engine sections (a) Hot sectio section n cleaning cleaning statem statement ent is done by (b) Cold section section cleani cleaning ng is done by vapour vapour degreasi degreasing ng and (c) Trichloro Trichloroethy ethylene lene is not suitabl suitablee for titanium titanium (d) (d) All All are are corr correc ectt 36. Stagger angle is done for (a) Wide chord is done done for for effic efficiency iency (b) Mid span shroud shroud is for stabi stability lity (c) First First stage stage fan fan blade blade is made made from from (i) Al alloy (ii) Titanium 37. Fire detectors Bimetallic (a) Thermocouple
Thermistors Surveillance Semi-conductors Infra-red ra r ays
Dielectric Capacitance
38. Fuel injector is made for Square law Crack pressure Better pr. At low pr. Inverted flow chamber Simplex Duplex Centrifugal Pre-vaporization Duplex Duplex Centrifugal Prevapourisation Simplex Si S implex Prevapourisation Centrifugal Duplex prevapourisation Centrifugal Pre-vaporization 39. As per international standards organization the following symbols reveal Restrictor Heater Absolute Filter Cooler Gauge 40. Fuel scheduling input variable are N1 and TGT MEC Ratio unit Amplifier V.S.V Sensor less F.C.U. Secondary channel E.E.C. 41. Match the following (a) Back pressure valve Spray nozzle (b) L.P speed governor Fuel pump (c) Dash pot throttle Annulus (d) P.R.V F.C.U. Solenoid 42. Match the following
High oil pressure pressure Oil quantity quantity increases increases at tank Defective pump Breather pressure leak Seal is broken FCOC leak
Partially Partially blocked blocked P & D Hot start Hung start/No start
43. A gas turbine engine is revolving at max r.p.m. If Wa increases (a) (a) C.P. C.P.R R incre increas ases es (b) C.P.R C.P.R decrea decreases ses P. t7 / P t2 (c) C.P.R C.P.R.. remai remains ns the the same same (d) (d) None None of of the the abov abovee 44. In Reheat, if the C.P.R. exceeds the limit then (a) Speed Speed governor governor adjustme adjustment nt is required required (b) Nozzle adjustment adjustment is is required required idle r.p.m. Adjustment Adjustment is required required (c) F.C.U F.C.U adjust adjustment ment is required required 45. F.C.U is running at idle. If OAT increases idle r.p.m. is constant, it is due to (a) (a) C.I. C.I.T T adjus adjustm tmen entt (b) Defec Defectiv tivee thro thrott ttle le Idle r.p.m = fn. (C.I.T.) (c) (c) Spee Speed d sens sensor or C.I.T. = fn. (OAT) (d) C.D.P C.D.P adjust adjustmen mentt 46. If an engineer finds that the EGT reading is less than that of normal it may be dure (a) Fault Faulty y electr electrica icall harness harness (b) Wire Wire length length is shortene shortened d during maint maintenanc enancee 47. Jet engine noise (a) Compresso Compressorr noise noise is less less than than jet – pipe noise noise (b) Low frequenc frequency y decays more more rapidly rapidly than high freque frequency ncy noise (c) . (d) (d) All All are are corr correc ectt
48. An air leak is internally at fan duct in compressor aircraft (a) N1, N2 wil willl incr increas easee (b) EGT EGT wil willl incr increas easee (c) Fuel Fuel flow flow will will increa increase se (d) (d) All All are are corr correc ectt 49. If an engine has been started using all components normal and hung start occurs, it may be due to (a) Closur Closuree of surge surge bleed bleed valv valves es (b) Opening Opening of surge surge bleed bleed valves valves (c) Lack of lubri lubricatio cation n in the beari bearing ng 50. If the CSU (constant speed unit) fails, the pilot will maintain (a) At climb, climb, the the r.p.m. r.p.m. Is mainta maintained ined at climb climb r.p.m. r.p.m. (b) At cruise cruise,, coarse coarse pitch pitch is constant constant (c) At climb, the pilot increase throttle throttle to fly at level flight condition condition 51. A cascade varies type thrust reverse (a) Does not take cowl-load cowl-load sharing sharing 52. When an electronic TGT amplifier fluctuates (a) Amplific Amplificatio ation, n, TGT, TGT, N2 sensor all all fluctuat fluctuates es 53. Starter has two holes
(a) (a) For For alig alignm nmen entt (b) For breath breather er sump sump vent vent 54. Exhaust nozzle is changed due to heat after long operation. It will cause (a) The thrust thrust to reduce reduce for for the amount amount of fuel fuel flow flow (b) The thrust thrust will will increase increase with with increase increase in EGT. EGT. (c) No apprecia appreciable ble change change in thrust thrust or EGT EGT as area area is the same same (d) The thrust will will increase due to increase of fuel fuel flow due to to more airflow airflow through inlet 55. Mark the correct statement (a) Compresso Compressors rs are loaded loaded more more in the the front stage stagess (b) Compresso Compressors rs are loaded loaded more more in the the rear stages stages 56. Bore scope inspection is does through the holes given. During inspection the HPT shaft is rotated (a) By removing removing the starter and and rotate through the starter engagement gears gears (b) By a drive pad provided provided for this this purpose in in the AGB AGB section of the engine engine (c) After After removing removing the c/c c/c only, only, B.S.L B.S.L can be done done (d) 7/8” socket socket and spanner spanner attache attached d in the hand cranking cranking pad pad
57. If the adjustment of the P & D valve on the FCU is lower than normal then (a) Hot star tart (b) (b) Hung Hung star startt 58. After engine light up the state does not cut off. The probable cause is (a) Starter Starter cut-of cut-offf circuit circuit is faulty faulty (b) Starter Starter drive spring spring is weak (c) Starter Starter bleed bleed valve valve does does not close (d) Either Either (a) (a) or (b) is corre correct ct 59. Hot shift and cold shift of engine is determined by (a) C.I.T C.I.T sensor sensor probe condition condition (b) T.I.T T.I.T sensor sensor probe condition condition (c) T.L.A T.L.A and and its position position w.r.t w.r.t M.E.C M.E.C (d) T.I.T T.I.T sensor sensor and C.I.T C.I.T sensor sensor condit condition ion 60. Engine anti-icing system condition and (a) Heats Heats up fwd, fwd, and rearw rearward ard simult simultaneo aneously usly (b) Heats Heats up fwd, and and rearward rearward in cycli cyclicc operation operation (c) Consists of dual dual butterfly valve, which regulates regulates the hot bleed bleed air in relation relation with a timer timer circuit (d) Can be used used in both both flight flight and ground ground operati operation on 61. L.O.P light illuminates during flight, what are the other parameters (associated with the same) that the pilot has to check on the cockpit indicators? (a) EGT and and r.p.m indica indicators tors for the the engine engine malfunctio malfunction n (b) N1 r.p.m. r.p.m. Gauge Gauge and and oil tempe temperatu rature re (c) Filter Filter cloggi clogging ng light light and EGT (d) No indicato indicators rs to check check but to cut-of cut-offf the engine. engine. 62. In the inlet of the hydraulic pump is blocked, what will happen? (Check Feb. 96) 63. In the pressurized chamber of the bearing sump area overboard drain is provided. This prevents (a) Compresso Compressorr air contamina contamination tion (b) Inward Inward air flow to the the chambe chamber r (c) (c) Oil Oil tank tank ove overf rflo low w (d) (d) None None of of the the abov abovee
64. What does the graph indicate? (a) Compre Compresso ssorr contam contamina inatio tion n (b) Undesira Undesirable ble engine engine condition condition (c) (c) Norm Normal al cond condit itio ion n (d) Engine Engine due due for for overh overhaul aul 65. In a turbo shaft engine, the electric starter has carbon brushes, which are worn out. This will (a) Decre Decrease ase the the starti starting ng speed speed (b) Not start start the engine engine (c) (c) Make Make EGT EGT high high (d) (d) All All are are corr correc ectt 66. A turbofan engine, with a hydro-mechanical hydro-mechanical FCU shows constantly poor r.p.m. Pick-up to maximum power. To detect the snag, mark the correct statement (a) C.D.P C.D.P.. senso sensorr and and N1 Cr (b) C.I.T C.I.T.. senso sensorr and and N2 Cr Cr (c) (c) R.p. R.p.m. m. sens sensor or (d) Gover Governor nor proble problem m 67. The power turbine turbo-shaft is running at higher r.p.m. There is a loss of oil pressure. The most probable cause is (a) The relief relief valve stuck stuck in closed closed position position (b) The relief relief valve valve is jammed jammed in in open positi position on (c) (c) Filt Filter er clog clogge ged d (d) Oil Oil spray spray jet clogge clogged d 68. Which of the following condition, for long time storage of engine (a) Lip (b) Cup (c) (c) Carb Carbon on-r -rub ubbi bing ng (d) (d) All All are are corr correc ectt 69. Engine operation inspection is O.K. except flame out during deceleration. The most likely cause is (a) Accelerat Acceleration ion and and decele decelerati ration on valve valve (b) Minimum Minimum flow valve setting setting (c) Maximu Maximum m flow flow valve valve setti setting ng (d) Governor Governor settin setting g (for maxim maximum um speed) speed) 70. Match the following condition, for long time storage of engine (a) Intake (b) (b) Fuel Fuel sys syste tem m (c) (c) Comp Compre ress ssor or (d) Exhau xhausst 71. Which is the hottest point in the engine? (a) Compre Compresso ssorr casing casing (b) Combus Combustio tion n chamber chamber casing casing (c) (c) N.G. N.G.V V casi casing ng (d) (d) Jet Jet pipe pipe cas casin ing g 72. If C.S.D fails during climb, (a) r.p.m. r.p.m. Remain Remainss the same same (b) Coarse Coarse pitch pitch is is select selected ed (c) Throttle Throttle is to be adjust adjusted ed for level level flight flight conditions conditions (d) (d) All All of the the abov abovee
73. Partial clogging of P & D valve results in (a) Hot star tart (b) (b) Hung Hung sta start rt..
1. Electric motion generator starter used in get engines (a) Separate Separate starter starter & generator generator not not reqd reqd (b) Common Common arma armatur turee is used used (c) Two Two field field windi windings ngs are are used used (d) (d) All All are are corr correc ectt 2. Air turbine starter used for get eng (a) Have Have light light to to torque torque rati ratio o low (b) Reqd. Reqd. supply supply of high vol of airflow airflow (c) Both Both a & b are correc correctt
3. In auto ign. System (a) Starter Starter ents of automatic automatically ally after after eng attains attains self acc. acc. Speed (b) It is designed primarily primarily to to ensure instant a NEOUS ign, ign, if an eng., begins to loose pwr in air (c) Automati Automaticall cally y restarts restarts when when flame flame out occurs occurs (d) (d) All All are are corr correc ectt 4. MCS (a) (b) (c) (d) (d)
The gap gap at igniter igniter plug plug is such such wider than than that that of spark spark plug As in a tip tip of igniter igniter plugs plugs not permit permitted ted to clean clean The ignitio ignition n of gas turbine turbine eng., eng., is not continuou continuouss as used in piston piston eng All All are are corr correc ectt
5. The problem of droop in governor can be reduced by (a) Using Using weaker spring spring requirin requiring g lower force force for valve movement movement (b) Making metering metering port narrow narrow so that that is requires requires small movement of the valve (c) Decrease Decrease the pr diffe different rential ial across across the metering metering valve valve (d) (d) All All are are corr correc ectt 6. Amongst the many inputs to the fuel control it senses (a) (a) N2 burn burner er pr (b) (b) As in a ITT, ITT, RPM RPM (c) As in in b CIP CIP (d) (d) As in c CI CIP 7. HOT SECTION OF ENG. INGLUDE (a) Comp, Comp, turbin turbine, e, combin combinati ation on (b) Combusti Combustion, on, turbine, turbine, exhaust exhaust (c) (c) Comp Comp,, comb comb,, exh exh,, (d) (d) None None abov abovee 8. Which is not part of the eng (a) (a) Main Main fuel fuel pump pump (b) (b) Fuel Fuel boo boost st pum pump p (c) Filter (d) (d) All All are are corr correc ectt 9. MCS regarding centrifugal comp (a) Pr. Pr. Rise Rise per per stage stage is is high high (b) Low front frontal al area area (c) Possi Possible ble damage damage to fod fod (d) (d) All All are are corr correc ectt 10. Lubrication oil use din gas turbine engine have (a) Low viscos viscosity ity index index (b) High viscos viscosity ity index index = low viscos viscosity ity (c) (c) High High pour pour poin pointt (d) (d) High High vis visco cosi sity ty 11. When water is injected in diffuser sec (a) N1 will will shift shift towa towards rds stal stalll (b) N2 will will shift away from stall (c) N2 will will shift shift towa towards rds stal stalll (d) As a & c are are corre correct ct 12. MCS (a) Pr pump pump is gear type type scaven scavenge ge pump is centr centrifuga ifugall type
(b) Pr. Pump Pump is venk type type sev sev pump is gear gear type type (c) (c) Both Both of of gea gearr type type (d) Pr. Pump Pump is vent type type & sev is vene vene type type 13. Propeller blade tracking is the process of determining (a) The plane plane of rotation rotation of propeller propeller w.r.t. w.r.t. a/c longitudin longitudinal al axis (b) That blade blade angle within the specified specified tolerance tolerance of each others (c) The position position of tips tips of the prop. prop. Blades Blades relative relative to to each other other (d) (d) All All are are corr correc ectt 14. Angle of attack of of blade is defined defined as (a) Angle Angle between between airfoil airfoil section section method line line & plane of rotation rotation (b) Angle Angle between between chord chord line & the the relative relative change change (c) Axis of blade blade rotation rotation during during pitch pitch change change 15. MCS (a) Geometric pitch is the the distance a propeller should mores fwd in one complete rev., rev., (b) Effective pitch pitch is the the actual distance a prop move fwd fwd in one complete rev. rev. (c) Slip is is difference difference betwee between n geometric geometric & effective effective pitch pitch (d) (d) All All are are corr correc ectt
16. Reverse pitch prop (a) Uses Uses far reduc reducing ing landi landing ng roll roll (b) When When used used high high fuel fuel is is consume consumed d (c) (c) All All are are corr correc ectt 17. Compressor blades are attached to the rotor by (a) Fir tree with retention retention device device (b) (b) Dove Doveta tail il slot slot (c) Bulb ulb ty type (d) (d) A & b are are corr correc ectt 18. Thermocouple type egt probes reconnected in (a) Fir tree with retention retention device device (b) (b) Dove Doveta tail il slot slot (c) Bulb ulb ty type (d) (d) A & b are are corr correc ectt 19. Procedure of reconturing-damaged area of fan blades is called (a) Blend lendin ing g (b) Shapi haping ng (c) (c) Burn Burnis ishi hing ng (d) (d) Blab Blabbe beri ring ng 20. The temp of air is higher in rear stages of comp. This is due to (a) (a) Diff Diffus usio ion n actio action n (b) Mechanica Mechanicall work. work. Done by by rotor rotor with with an (c) Mechanica Mechanicall energy energy is convert converted ed into heat heat energy energy (d) (d) All All are are corr correc ectt 21. The type of eng. Used in helicopter is (a) Shaft (b) Prop
(c) Fan (d) As in in a with with free free turbi turbine ne 22. Inc., the exhaust nozzle area will result in (a) N2 dec (b) (b) Thru Thrust st dec dec (c) N1 inc. nc., (d) As in in a with with free free turbi turbine ne 23. Diffuser in centrifugal comp (a) (a) Inc, Inc, stat static ic pr (b) Inc, Inc, velocit velocity y and pressu pressure re (c) Increase Increasess kinetic kinetic velocity velocity and decreas decreases es pressures pressures (d) Decrease Decreasess velocity velocity and pressu pressure re 24. In the compressor RPM engine speed remain constant and mass airflow increased (a) Pressure Pressure ratio ratio will increase increase and stall stall margin margin will decrease decrease (b) Pressure Pressure ratio ratio will increase increase and stall stall margin margin will inc (c) Pr. Ratio Ratio & stall stall margin margin will will dec dec (d) Ratio Ratio will will dec & stall stall 25. TSFC change (a) Direc Directly tly by thrust thrust (b) Invers Inversely ely by p. p. ratio ratio (c) Direc Directly tly by pr. pr. rati ratio o 26. MCS (a) Temp drop takes takes places thru the turbine i.e. approx equivalent to to the temp rise occurred in the comp (b) Temp drop takes takes place than the turbine turbine is much greater greater than the temp temp rise of the comp 27. Stall characteristic of comp. Blade (a) Begin to in., at higher altitude altitude due to higher higher Reynolds no., & thus dec., efficiency of the eng. (b) Remains Remains same same on the ground ground & at higher higher altit altitude. ude. 28. Components used in the secondary air thrust reverse type (a) (a) Bloc Blocke kerr door door (b) As in A cascad cascadee vane vane (c) As in in b trans translat lating ing slee sleeve ve (d) (d) As in c thr thrus ustt 29. In modern jet eng., fue metered fuel by (a) Airflow may be metered by keeping the pr., pr., drop across the metering valve constant constant while varying varying the valve orifice (b) Valve orifice orifice may be kept constant constant size and and the pressure pressure difference difference varied (c) (c) Vary Varyin ing g bath bath (d) (d) All All are are corr correc ectt 30. A BURNER design, which reduces cooling air req. by 50% & dec., burner wt., by 20% is (a) (a) Floa Floatt wall wall (b) In wa wall (c) Annu nnular lar (d) (d) Reve Revers rsee flow flow 31. During cruise (a) Igv & stator stator vanes vanes in closed closed position position
(b) Igb & stat stator or in full fully y open open 32. Fire extingquishing agents (a) Freon (b) (b) Meth Methyl yl bro bromi mide de (c) Cholor Cholorabr abromo omoeth ethane ane (d) (d) All All are are corr correc ectt 33. When fire extinguishing agents introduced into the engine (a) Water Water & chlorid chloridee mixture mixture wash wash is necessa necessary ry (b) Extinguishing agents will will evaporate evaporate itself and no need of water wash wash (c) It is normal normal & no no need need of preca precaution ution (d) Shut do the the eng & send send it to to the shop 34. Continuous loop fire detection system (a) Ceramic beads looses resistant after temp, rise & causes fire fire warning & require require manual reset reset (b) The ceramic beads looses resistant resistant after temp temp rise & give fire fire warning will will automatically automatically resets itself when cooled 35. MCS (a) In two wire thermal s/w type type fire detection detection can withstand withstand either an open open or a short & still remain remain in function (b) In fenw fenwal al typ typee also also (c) (c) A & B are are corr correc ectt 36. MCS (a) In nozzle nozzle diaphragm diaphragm area area is measured measured at the exit of the the vanes (b) Total Total area is sum sum of all all areas betwee between n the vane (c) Nozzle Nozzle area effec effects ts the effici efficiency ency of the the eng (d) (d) All All are are corr correc ectt 37. MCS (a) Pr. Of superso supersonic nic air as it flows flows that that the converge convergent nt nozzle nozzle inc (b) As in a pr. Of super sonic air air is flows thru thru a convergent nozzle nozzle is inversely inversely proportional to the temp (c) As in a the pr of supersonic air as it flows thru thru convergent nozzle nozzle is directly proportional to the temp. (d) The pt. of supersoni supersonicc air is it flows thru thru convergent convergent nozzle nozzle dec. 38. When a turbine stage is damaged will have (a) Vibratio Vibration n throughout throughout the eng. eng. But clearl clearly y at low speed. speed. (b) Eng. Vibration Vibration through out pm range range but indicated indicated amplitude amplitude reduces as as rpm reduces reduces (c) Vibration through through out the the eng., but most probably probably at high speed & fuel fuel flow (d) Eng. Vibrates Vibrates through rpm range but but is more more prommcal in cruise or idle condition condition 39. Eng. Trumbles during starting at low power cruise condition the reason is (a) Pressuri Pressuring ng & damp valve malfuncti malfunction on (b) (b) Crac Cracke ked d an duct duct (c) Fuel Fuel contro controll malfun malfuncti ction on (d) (d) All All are are corr correc ectt 40. Fuel is delivered at high-pressure thru the fact control unit thru (a) (a) Gear Gear type type pump pump (b) Centri Centrifug fugal al boost boost type type (c) Gear type type & centri centrifugal fugal boost pump (d) Filter, Filter, gear gear type pump pump & centrif centrifugal ugal pump pump
41. Trimming of eng. Is necessary (a) (a) Afte Afterr fen fen chan change ge (b) As in in a to set set maxi maximum mum thrust thrust (c) (c) As in b to set set idle idle rpm rpm (d) (d) All All are are corr correc ectt 42. Water contain in fuel will (a) Clog Clog the the pump pump out out let let (b) (b) Caus Causee corro corrosi sion on (c) Can cause cause engine engine performanc performancee loss or even even lame out jeppese jeppesen n 262 (d) All All the the above above correc correctt 43. Filter used in get eng. (a) Screer Screer disk disk type type steel steel insert insert filter filter (b) Water type type (water, (water, screen screen fuel filter) (bowl (bowl type type filter) filter) (c) Cartri Cartridge dge type type filter filter (d) (d) All All the the corr correc ectt 44. Oil pt. indicator uses (a) (a) Ther Thermo moco coup uple le (b) (b) Resi Resist stan ance ce bulb bulb (c) (c) Auto Auto syn syncc syst system em (d) Diaphrag Diaphragm m repai repairr of bellows bellows 45. Egt indicator include (a) Red dial dial at max max gas temp temp for for wet & operatio operation n (b) Green arc from max permissible temp, for continuous continuous operation to to minimum recommended recommended by the eng. Manufacture (c) Yellow / amber are from from max temp for continuous continuous operation operation to max permissible gas temp (d) (d) All All are are corr correc ectt
46. Vibration momtor (a) Latest Latest type type uses uses piezo piezo electr electric ic type type (b) As in a also also uses velocity velocity pickup pickup 47. When an eng is operation without its antince valve on epr inc., when other parameters readings are normal the reason (a) Ice formed formed the inlet cowling causing causing low piston piston PIC probe probe parts act as PS2 PS2 (b) Causing Causing high high pr. On On PT2 PT2 probe probe (c) (c) Fuel Fuel malf malfun unct ctio ion n (d) Rise is is engine engine pr ratio ratio indicatio indication n in cockpit cockpit 48. Motor less type fuel flow meter senses fuel by (a) Vane Vane moves moves agai against nst mass mass flow flow (b) Two signals signals through through transdu transducers cers (c) Impell Impeller er & synch synchron ronous ous unit unit 49. P & D valve acts as a (a) (a) Flow Flow divi divide der r 50. Provision for drain of fuel in eng. (a) Feoe have have provision provision for for slight slight Crain Crain if requd requd (b) Fuel heater heater will will have provisi provision on for same same drain of fuel fuel
(c) Combusti Combustion on chamber chamber have have provisi provision on for drain drain 51. Wet thrust means (a) Max power power availa available ble when when water water is injected. injected.
MUMBAI : 29 SEMESTER EXAMINATION JET ENGINES – THEORY AND CONSTRUCTION
Part – I QUIZ TYPE 1. Which of the following is not an air-breathing engine? (a) Rocket (b) Pist iston (c) Ramjet (d) Turbof Turbofan an engine enginess 2. The general method of attaching compressor blades is (a) By fixture fixture arran arrangeme gement nt and and locking locking (b) By doveta dovetail il arrang arrangement ement and lockin locking g (c) By weldin welding g to the disc disc (d) Both Both B & C are are corre correct ct 3. The basic types of turbine blades are (a) Reacti Reaction on and and conve convergi rging ng (b) Tange Tangenti ntial al and converg converging ing (c) Reacti Reaction on and and impuls impulsee (d) Impuls Impulsee and vector vector 4. The advantages with split spool compressor over single spool compressor is (a) Better Better compress compression ion ratio ratio and and surge margin margin
(b) More turbine turbine wheel wheelss can be used used (c) The velocity velocity of air enteri entering ng the combustion combustion chamber chamber is increase increased d (d) Number Number of beari bearings ngs require required d is reduced reduced 5. To produces a thrust of 9600 lbs a jet engine consumes 900 gallons of fuel per hour. Given that one gallons of fuel weighs 8 lbs. What is the thrust specific fuel consumption of the engine? (a) 0.075 0.075 lbs/ lbs/hr/ hr/lb lb thru thrust st (b) 0.750 0.750 lbs/h lbs/hr/l r/lb b thrust thrust (c) 1.330 1.330 lbs/ lbs/hr/ hr/lb lb thru thrust st (d) (d) None None of of the the abov abovee 6. Compressor blades are not rigidly fixed but a slight movement is allowed in order to (a) Provide Provide flexibi flexibility lity for blade blade replace replacement ment (b) Provide Provide toler tolerance ance for blade blade expansion expansion (c) Reduce Reduce vibration vibration stresses stresses produced produced by high velocit velocity y air stream stream (d) (d) All All the the abo above ve 7. Turbine blades creep with increase is temperature and operating time. This means (a) The blades blades elonga elongates tes (b) (b) Blad Bladee wear wearss out out (c) The blade losses losses its its toughn toughness ess (d) (d) All All the the abov abovee 8. Which of the following engine casing is the hottest during engine run (a) H.P H.P turbin turbinee casing casing (b) L.P L.P turb turbine ine casing casing (c) Jet Jet pipe pipe (d) Combus Combustio tion n chamber chamber casing casing 9. What is the primary advantage of an axial flow compressor over a centrifugal flow unit? (a) Easie Easierr mainte maintenan nance ce (b) High High front frontal al area area (c) (c) Less Less expe expens nsiv ivee (d) Great Greater er press pressure ure rati ratio o 10. The compression ratio of an axial flow compressor is a function of (a) The No. No. Of compr compress essor or stage stagess (b) (b) Roto Rotorr diame diamete ter r (c) (c) Diff Diffus user er area area (d) Air Air inle inlett velo velocit city y 11. Which of the following types of combustion sections are used in aircraft turbine engines. (a) Variable Variable can can annular annular and cascade cascade vanes vanes (b) Annular Annular varia variable ble and and cascad cascadee vane (c) Can multiple multiple can and variable variable (d) Multiple Multiple can, can, can can annular, annular, and and annular. annular. 12.The exhaust section of a turbine engine is designed to (a) Impart Impart a high exit exit velocity velocity to the exhaus exhaustt gases (b) Swirl Swirl the the exhau exhaust st gases gases (c) Increase Increasess temperature temperature there there by increas increasing ing velocity velocity (d) Decrease Decreasess temperature temperature there there by increasing increasing pressure pressure 13. Why do some turbine engines have more than one turbine wheel attached to a single shaft? (a) To facilita facilitate te balancin balancing g of the turbine turbine assembl assembly y (b) To straightened straightened the airflow before it entered the the exhaust area
(c) To help stabilize the pressure pressure between between the compressor compressor and and the turbine (d) Decrease Decrease tempera temperature ture there there by increasing increasing pressure pressure
14. What is the purpose of directing bleed air to the bearing compartment? (a) It increase increasess oil pressure pressure for for better better lubricat lubrication ion (b) It provides provides a high volume volume of oil oil to the most most critical critical bearings bearings (c) It heats heats the oil oil to the proper proper operati operating ng temperat temperature ure (d) It heats heats the oil oil to the bearin bearing g compartme compartments. nts. 15. Which of the following variables affect the inlet air density of a turbine engine? (a) The turbine turbine inlet temperat temperature ure (b) The altitude altitude of the aircraft aircraft (c) Compre Compressi ssion on ratio ratio (d) The turbin turbinee and compre compressor ssor effici efficiency ency 16. Dirt particles in the air being introduced into the compressor of a turbine engine will form a coating on all but which of the following (a) (a) Turb Turbin inee bla blade dess (b) Compre Compresso ssorr blad blades es (c) Casin asings gs (d) Inlet Inlet guide guide vanes vanes 17. Mark the correct statements (a) Roller Roller bearings bearings take take both both axial axial and radial radial loads loads (b) Ball beari bearings ngs take take both axial axial and radia radiall loads (c) Given the same diameter, diameter, the ball ball bearing takes greater greater load than the roller bearings (d) None of of the above above statem statement ent is correct correct 18. In the twins spool compressor system the first stage turbine drives the (a) (a) N – 1 com compr pres esso sor r (b) (b) N – 2 com compr pres esso sor r (c) (c) N – 1 & comp compre ress ssor or (d) The fan. an. 19. What are the two functional elements in a centrifugal compressor? (a) Bucket Bucket and expand expander er (b) Impell Impeller er and and diffu diffuser ser (c) Turbin Turbinee and and compr compress essor or (d) Air Air intake intake and and expel expeller ler 20. Newton’s first law of motion states (a) To every every action there there is an equal equal and opposites opposites re action action (b) Force Force is proportiona proportionall to the product of mas masss and accelerati acceleration on (c) Every Every body persist persistss in its product product of mass mass and accelerati acceleration on (d) Heat energy energy and mechanical energy are are quantitatively quantitatively inlet inlet convertible convertible
21. Engine pressure ratio for power assessment is determined by (a) Multiplying the engine inlet inlet total pressure by turbine out let total pressure (b) Dividing turbine turbine outlet outlet total pressure by engine inlet inlet total pressure (c) Dividing engine engine inlet total pressure pressure by turbine outlet outlet total total pressure (d) Dividing compressor delivery pressure by engine engine inlet inlet pressure pressure
22. An advantages of the centrifugal flow compressor is its high (a) (a) Ram Ram eff effic icie ienc ncy y (b) Peak Peak effici efficienc ency y (c) Press Pressure ure rise rise per per stage stage (d) (d) Fron Fronta tall are areaa 23. In a gas turbine engine combustion occurs at a constant (a) Veloc locity ity (b) (b) Pres Pressu sure re (c) Densi nsity (d) Volume 24. Purpose of the stator vanes in an axial flow compressor is to (a) Increase Increase the veloci velocity ty of airflow airflow and prevent prevent swirli swirling ng (b) Straighte Straighten n the airflow airflow and eliminate eliminate turbule turbulence nce (c) Decrease Decrease the velocit velocity y prevent prevent swirling swirling and boost the pressure pressure (d) Prevent Prevent compress compressor or stalls stalls and elimina eliminate te surge 25. In a (a) (b) (c) (d)
turbine engine with a dual spool compressor the low speed compressor Always turns at the same speed compressor, compressor, the the low speed compressor compressor Is connected connected to the the high-pressure high-pressure compressor compressor through a reduction gear. Seeks Seeks its its own own best best operat operating ing speed speed Is coupled to the high-speed high-speed turbine mechanically but through a reduction gear.
26. How many ignitions are normally used on a turbine engine having nine burner cans? (a) One (b) Two (c) Nine (d) (d) Eigh Eighte teen en 27. Using standard atmospheric conditions the standard sea level temperature is (a) (a) 15 degr degree eess C (b) (b) 0 deg degre rees es F (c) (c) 0 degr degree eess C (d) (d) 273 273 deg degre rees es K
28. Which of the following is the ultimate limiting factor of turbine engine operation? (a) Compresso Compressorr inlet inlet air temperatu temperature re (b) Compresso Compressorr outlet outlet air air temper temperatur aturee (c) Burner Burner can pressu pressure re (d) Turbine Turbine inlet inlet temperat temperature ure 29. Where is the highest gas pressure in a turbo jet engine experienced? (a) At the the outlet outlet of the the burner burner section section (b) At the the entrance entrance of the the turbine turbine section section (c) At the the outlet outlet of the tail tail pipe pipe sectio sections ns 30. What turbine engine sections provides for proper mixing of the fuel and air? (a) Combus Combustio tion n sectio section n (b) Turbin Turbinee sectio sections ns (c) (c) Diff Diffus user er secti section onss
(d) Compre Compresso ssorr secti sections ons
GAS TURBINE ENGINES – MODEL PAPER NOTE: 1. Answer the questions by circling the night answer 2. Answer the essay questions questions on the separate shuts provided provided 3. Write your name on the top R.H corner PART I – QUIZ TYPE: 1. Both temps. And pr. Rise during combustion in (a) The Brayto Brayton n cycle cycle (b) (b) The The otto otto cyc cycle le (c) The otto otto bray brayton ton cyc cycle le (d) None None of the the above above is corr correct ect 2. If the Pt2 probe is famed in a jet engine due to lee formation? (a) ETR ETR will will show show high high (b) EPR EPR wil willl show show low (c) EPR EPR will will not not be be affec affectt (d) (d) EGT EGT will will go go high high 3. What is the basic function of combustion chamber is a gas engine? (a) Change Change potentia potentiall energy energy of high speed speed air air into ram ram pr (b) Change Change kinetic kinetic energy energy of air air into pr. pr. Energy Energy (c) Reduce the speed of air air and increase increase the volume volume of air air and accelerate accelerate it (d) Change Change the thermal thermal energy energy to potentia potentiall energy energy
4. Which statement is true regarding jet engines? (a) At the lower engine speeds thrust increases rapidly rapidly with small increases increases in r.p.m. r.p.m. (b) At the higher engine speeds thrust increases rapidly rapidly with small increases increases in r.p.m. (c) The thrust delivered delivered per found of air consumed is less at high delivered delivered per pound of low altitude altitude (d) The thrust delivered delivered for a given given small increase increase in r.p.m. is is independent of the the speed range at which rpm is increased 5. Using standard atmospheric conditions, the standard sea level temperature is (a) 590C (b) 590 F (c) 290 C
(d) 00 C 8. ATA system specification 80-00-00 represents the chapter (a) (a) Engi Engine ne oil oil sys syste tem m (b) Igniti Ignition on syste system m (c) Engine Engine star startin ting g syste system m (d) Engine Engine instr instrume ument nt system system 9. The area of the after turner jet pipe is forger than normal jet pipe in order to (a) Reduce Reduce air veloci velocity ty (b) As in in A for bette betterr combusti combustion on (c) (c) To pre preve vent nt ckok ckokin ing g (d) (d) None None of of the the abov abovee 10. The exhaust system components are (a) Manufact Manufactured ured from from nickel nickel or titanium titanium for high high strength strength (b) Made from from nickel nickel or titanium titanium for for high stren strength gth (c) Made from from high high carbon carbon steel steel for for strength strength (d) None of of the above above statem statements ents is is correct correct 11. Mark the correct statement w.r.t the by pass engine (a) The low by pass engine, the bypass ad core core airflows are combined combined in a mixture mixture unit before exiting through the propelling nozzle (b) In a high by pass engine. The by pass and core flows flows a reduction reduction separately separately (c) The lower lower the by pass the the higher higher the propell propeller er of (d) All three three stateme statement nt are are wrong wrong 12. A variable area propeller nozzle: (a) Generally on engine without without reheat reheat because performance performance gain is offset by increase increase in weight weight (b) Gives Gives better fuel fuel economy during during reheat reheat applicat application ion (c) Uses lower lower nozzle nozzle area area during during take off off for greater greater (d) It used on high high by pass engines engines for for better better fuel economy economy 13. What is the purpose of directing bleed air to the bearing compartment? (a) It seals seals the oil in in the beari bearing ng compartm compartment ent (b) It seats seats the oil to the proper proper operati operating ng temperatu temperature re (c) It provides provides a high volume volume of oil oil to the most most critical critical bearings bearings (d) It increase increase the the oil pr for for better better lubrica lubrication tion 14. It the water injection system operation the addition of methanol will (a) Restore Restore turbin turbinee inlet inlet temperatu temperature re (b) (b) Brin Bringd gdow own n N2 rpm rpm (c) Lower Lower freezin freezing g point point of water water
(d) Both Both a and and c are are corr correct ect 15. Mark the correct statement regarding thrust resources (a) Mixed Mixed exhaust exhaust type engine enginess need only only one resourc resources es (b) In high by pass pass turbo fans, recourse recourse of secondary air is more effective than that that of primary primary air (c) Both primary primary and and secondary how are reversed by using separate reverses reverses (d) All of of the above above statem statements ents are are correct correct
16. Rotation pad on the accessory G.B is provided for (a) Filterin Filtering g alternat alternatee tacho-ge tacho-genera nerator tor (b) (b) For For N2 rota rotati tion on (c) To facil facilita itate te fan balan balancin cing g (d) All the the above above stateme statements nts are are correct correct 17. In the APU (a) Turbine Turbine blade bladess are are made made of titanium titanium (b) APU has has reverse reverse flow flow combusti combustion on chamber chamber (c) It is supported supported by plain journal bearing in the front and roller bearing at the rear (d) One of the above above stateme statement nt is correct correct 18. Power point is expressed in (a) (a) Deci Decibe bell – soun sound d (b) (b) Cent Centis istr trok okee (c) Poise (d) Degree gree F 19. Anti icing of jet engine air inlets is commonly accomplishedly (a) Electric Electrical al heating heating elements elements inside inside the inlet inlet guide vane vane (b) Engine Engine blud air air ducted ducted through through critic critical al areas areas (c) Electrical heating elements elements located, located, within within the engine engine air inlet cowling cowling (d) Spent Spent exhaust exhaust gas ducted ducted through through critical critical areas areas 20. The fire detection system that uses a single course surrounded by a temperature sensitive insulating medium in a tube is (a) (a) Fenw Fenwal al syst system em (b) (b) Kidd Kiddie ie sys syste tem m (c) Thermo Thermocou couple ple syste system m (d) (d) Squi Squist stss syst system em 21. Which of these characteristics is desirable in turbine engine oil (a) (a) Low Low fla flash sh poin pointt (b) (b) High High flas flash h poi point nt (c) (c) High High vola volati tili lity ty (d) (d) Low Low visc viscos osit ity y inde index x 22. Thrust reverse utilizing a pneumatic actuating system usually receive air from (a) The engi engine ne bleed bleed air air syste system m (b) An on board board recipro reciprocatin cating g compress compressor or (c) One or or more more high pressure pressure air battl battles es (d) Environme Environmental ntal control control system. system.
23. The rearward thrust capacity of an engine with the thrust reverse system deployed is
(a) (b) (c) (d)
Less tharits tharits forward forward capacity capacity Equal to or less less than its forward forward capacity depending on ambient ambient conditions and system system design Equal Equal to its forward forward capacity capacity More than its forward forward thrust capacity capacity since engine bleeds are kept closed closed
24. What is the function of an engine fire detection system? (a) To discharge discharge the powerplane powerplane fire extinguishing agent agent at the origin of the the fire (b) To activate activate a warning warning device device in the event event of a power power plant fire fire (c) To identif identify y the locatio location n of a power power plant ifre ifre (d) To idienfy idienfy the exting extinguishe uisherr son that that spot spot 25. Mark the correct statement as applicable to magnetic plugs (a) They are are removed removed at periodic periodic intervals intervals for conditio condition n monitoring monitoring (b) They are connected to a cock pit warming system system to give an in flight indication indication (c) All the the above above statem statements ents are corre correct ct 26. Squeeze rpm type bearings are used on some engine to (a) Reduce Reduce vibra vibration tion level level of engine engine (b) Modify Modify the radial radial motion motion of rotating rotating assembl assembly y (c) Reduce Reduce possibil possibility ity of damage damage by fatig fatigue ue (d) Contri Contribut butee to all the the above above 27. Mark the correct statement regarding T.R operation (a) T.R. can can be used in the air air to change change direction direction of a/c heading heading (b) T.R is to be actuated at a height of 100 before before a/c touch down down for minimum use of run way (c) The T.R should should be held held in reverse reverse till till the a/c comes comes to a complete complete halt halt (d) None of of the above above statem statements ents is is correct correct 28. The air and oil are separated in a jet engine oil system by returning the scavenge oil to (a) The bott bottom om of the the reserv reservoir oirss (b) The deaira deairator tor at the the top of the the reservor reservor temp temp (c) The pressu pressuriz rized ed tank tank (d) To the centrifug centrifugal al separ separator ator 29. The net reverse thrust available on a high by pass engine having only tan revouser is approxionately (a) 40 % (b) 80% (c) 60% (d) 100%
30. In a jet engine otherwise behaving normally there are reports of flameout during descent the problem is (a) Metering Metering orifice orifice in FCU FCU clogged clogged (b) Minimum Minimum flow valve malfuncit malfunciton on (c) Fan Fan exit exit guide guide vane vane icing icing (d) Malfunct Malfunction ion of accelerat acceleration ion and decelerati deceleration on valve 31. On a jet engine the EGT reading is high as noticed by he AME during comparison check in transit. The cause could be (a) Party Party comp compres ressor sor blad blades es (b) One of the the thermocou thermocouple ple probes probes is open open circuit circuit (c) Turbine Turbine blade rub at at periphe periphery ry (d) Both Both A & C are are correc correctt
32. In and engine with hydromechanical hydromechanical system F.C.U pilot reports engine acceleration without throttle movement the possible cause is (a) (a) Loss Loss of of spad spad sen sense se (b) (b) Loss Loss of of CDP CDP sens sensee (c) C.I.T C.I.T sensor sensor failur failuree (d) Any one of the the abov abovee 33. Compressor air leakage in a turbo fan engine is noted by (a) (a) Rise Rise in r.p r.p.m .m (b) Rise Rise in vibra vibratio tion n (c) (c) Rise Rise in EGT EGT (d) (d) All All the the abov abovee 34. Engine hot start is indicated by (a) (a) EPR EPR incr increa ease se (b) (b) EPR EPR inc incre reas asee (c) Fuel Fuel flow flow incre increase ase (d) Faster Faster rise in EGT EGT in proporti proportion on to N2 rotor rotor rpm increase increase 35. If the crack pressure adjustment of the pressuring valve is on the lower ride that required than (a) Secondar Secondary y fuel fuel will will flow flow carlier carlier (b) Start Start EGT EGT will will be high higher er (c) Stall Stall margi margin n will will be reduce reduced d (d) All All above above is corr correct ect 36. What is the possible cause when a turbojet engine indicates no change in power setting parameters lent oil temperature is high (a) Gear Gear box box real real leakag leakagee (b) Engine Engine main main bearing bearing distress distress (c) High High oil oil sum sump p press pressure ure (d) Oil scavenge scavenge pump not effec effective tive 37. Mark the incorrect match match (a) Turbo prop (b) Turbo jet (c) Rocket (d) High by pass jet
Best TSFC Best thrust to weight ratio maximum air consumption least noise
38. Why is the necessary to control acceleration and deceleration rates of turbine engines (a) To preve prevent nt blow blow out out due to to rich rich (b) To enable enable to heat and and cool the engine engine at control controlled led rates rates (c) To prevent friction between between turbine wheels and the case due to expansion and contraction (d) To operate operate engine engine at optim optimum um fuel fuel consumptio consumption n 39. When the pilot selects water injection during take of which of the following observation is true? (a) The engine engine r.p.m r.p.m rises rises (b) The engine r.p.m. Rises Rises and J.P.T J.P.T gas slightly above above acceptable limit (c) (c) J.P. J.P.T T incr increa ease sess (d) Fuel consumpt consumption ion becomes becomes less that that normal due to water water addition addition 40. Turbine blades air more susceptible to operation damage than compressor blades because of (a) Highe Higherr centrif centrifuga ugall loading loading (b) Exposure Exposure to high temperat temperature ure (c) High pressu pressure re and high high velocity velocity gas flow flow (d) (d) All All the the abov abovee
41. What is the first engine instrument indicating successful start of a turbine engine? (a) L.P.S L.P.S spool spool rotati rotation on (b) Rise in exhaus exhaustt gas temperat temperature ure (c) Rise Rise in in oil oil pressu pressure re (d) Rise Rise in engi engine ne fuel fuel flow flow 42. Hot section inspection for many modern turbine engines are required (a) Only Only at engine engine overha overhaul ul (b) Only when when an over temper temperature ature or speed speed is reporte reported d (c) On a time time or or cycle cycle basis basis (d) During During ever every y C of A renew renewal al
SEMESTER IV 1. A severs condition of chafing or fretting in which a transfer of meal from one part to another occurs. If called (a) Goug ouging ing (b) Burni urning ng (c) Erosi osion (d) Galli lling 2. Compressor stall is caused by (a) A low angle of attack attack airflow airflow through through the first first states of compress compression ion (b) A high angle angle of attack attack airflow through the first stages stages of compression compression (c) A high velocity velocity airfl airflow ow in the the engine engine inlet inlet (d) Rapid Rapid engine engine deceler decelerati ation on 3. Hot spots in the combustion section of a turbojet engine are possible indicator of (a) Foreig Foreign n objec objectt damag damagee (b) Fault Faulty y ignit igniter er plug plugss (c) Dirty Dirty comp compres ressor sor blad blades es (d) Malfunct Malfunctionin ioning g fuel nozzles nozzles 4. In what section of turbojet engine is the jet nozzle located? (a) (a) Comb Combus usti tion on (b) Turbi urbine ne (c) (c) Comp Compre ress ssor or (d) Exhau xhausst 5. What is the purpose of the pressurization and dump valve used on turbo jet engine? (a) Controls the the pressure of of the compressor compressor outlet by dumping air when pressure reaches reaches an established level. (b) Allows fuel pressurization pressurization of the engine when starting and operating operating and dumps fuel fuel pressure of engine shutdown (c) Controls compressor stall stall by dumping compressor compressor air under certain certain condition (d) Maintain fuel pressure pressure to the fuel fuel control valve and dumps excessive excessive fuel bake to the the fuel tanks 6. What is meant by a shrouded turbine? (a) The turbine turbine blades blades are shaped shaped so that that their ends ends form a band band or shroud (b) Each turbine turbine wheel wheel is enclose enclosed d by a separate separate housing housing or shroud
(c) The turbine wheel wheel is enclosed by a protective protective shroud to contain the blades in case of failure (d) The turbine wheel has shroud or duct duct which provides provides cooling air to the the turbine blades
7. Why does a turbine engine require a cool off period before shutting it down? (a) To allow the surfaces surfaces contacted by the lubricating lubricating oil to to return to normal operating operating temp (b) To burn burn off excess excess fuel fuel ahead of the the fuel contro controll (c) To allow allow the turbine turbine wheel wheel to cool before before the case case contracts contracts around around I (d) To avoid avoid seizure seizure of of the engine engine beari bearings ngs 8. Which of the following types of combustion sections are used in a/c turbine engines (a) Variable, Variable, can-annula can-annular, r, and and cascade cascade vane vane (b) Annular, Annular, variable variable and and cascade cascade vane vane (c) Can multiple multiple can, and variable variable (d) Multiple Multiple can, can, annula annular, r, and can can annular annular 9. Why do some turbine engines have more than one turbine wheel attached to a single craft? (a) To faciliti facilities es balancing balancing of of the turbine turbine assemb assembly ly (b) To straighte straighten n the airflow airflow before it enters enters the exhaust exhaust area area (c) To help stabilize the pressure pressure between between the compressor compressor and and the turbine (d) To extract extract more power power from the exhaust gases than a single single wheel can absorb 10. The compression ratio of an axial flow compressor is a function of the (a) Number Number of comp compres ressor sor stag stages es (b) (b) Roto Rotorr diame diamete ter r (c) (c) Diff Diffus user er area area (d) Air Air inle inlett velo velocit city y 11. What is the function of a fire detection system? (a) To discharge discharge the power plant fire extinguishing system at the origin of the fire fire (b) To warn warn of the presence presence of fire in the the rear section section of the the power plant plant (c) To activate activate a warning warning devices devices in the the event of a power power plant fire fire (d) To identif identify y the locatio location n of a power power plant fire fire 12. How does carbon dioxide extinguish and engine fire? (a) A continuous continuous loop loop fire detect detector or is what type type of detector detector (b) By lowering lowering the temp temp to a point where where combustion will not take places (c) The gas spray spray liquefi liquefies es in the heat heat and smoothers smoothers the the fire (d) The high-pressure high-pressure spray lowers the temperature and blows out out the fires. fires. 13. A continuous loop fire detector is what type of detector? (a) (a) Spot Spot dete detect ctor or (b) Overhe Overheat at detec detector tor (c) Rate Rate of temp temp rise rise detec detector tor (d) Radiation Radiational al sensing sensing detection detection
14. What is the operating principle of the spot detector sensor in a fire detection system? (a) Resistant core material material that that prevents current flow at normal temp (b) Fuse material material that that melts melts at high temp temp (c) A convention conventional al thermoco thermocouple uple that that produces produces current current flow (d) A bimetallic bimetallic thermoswitch thermoswitch that closes when heated heated to a high temp.
15. Which of the following is the safest fire-extinguishing agent to use from a standpoint of toxicity and corrosion hazards? (a) (b) (c) (d)
Cholorbro Cholorbromoma momathane thane (Halon (Halon 1011) Dibromodi Dibromodifluor fluorometh omethane ane (Halon (Halon 1202) 1202) Bromochlo Bromochlorodif rodiflurom luromometh omethane ane (Halon (Halon 1211) 1211) Bromotri Bromotriflur fluromome omomethane thane (Halo (Halon n 1211)
16. Which of the following is not used to detect fires in reciprocating engine necellers? (a) (a) Smod Smodee dete detect ctor orss (b) Overhe Overheat at dete detecto ctors rs (c) Rate Rate of temp temp rise rise detec detector torss (d) (d) Flam Flamee detec detecto tors rs 17.What is the principle of operation of the continuous loop fire detector system sensor? (a) Fuse material material which which melts melts at high high temp temp (b) Core resistance resistance material material which which prevents prevents current flow at normal temp temp (c) A conventiona conventionall thermocoup thermocouple le which produce producess a current current flow (d) A bimetallic bimetallic thermo switch which which closes when heated to a high temp 18. Why does the fenwal fire detection system use spot detectors wired in parallel between two separate circuits? (a) A control unit is used to isolate isolate the bad bad system in case of of malfunction (b) This installation installation is equal to to two systems systems a prime system system and a reserve reserve system (c) The duel terminal terminal thermo switch switch is used so that one terminal terminal is wired to to a bell the other other to a light (d) A short may may exist in either circuit without without causing a false fire fire warning. warning. 19. Which of the following fire detector system measures temp rise compared to a reference temp? (a) Fenwa Fenwall conti continuo nuous us loop loop (b) (b) Ther Thermo moco coup uple le (c) (c) Ther Therma mall swit switch ch (d) Lindberg Lindberg continuou continuouss element element 20. A fuel or oil fire is defined as a (a) (a) Clas Classs B fire fire (b) (b) Clas Classs D fire fire (c) (c) Clas Classs A fire fire (d) (d) Clas Classs C fire fire 21.When starting a turbojet engine (a) A hot start start is indicated indicated if the exhaust gas temperature temperature exceeds specified specified limit limit (b) An excessive excessively ly lean mixtur mixturee is likely likely to cause cause a hot start (c) The engine should start between 60 to 80 seconds seconds after the fuel shut off lever is opened (d) Release the starter switch switch as soon as indication of light off occurs 22. In the dual axial flow or twin spool compressor system the first stage turbine drives the (a) N1 and and N2 N2 compr compress essors ors (b) (b) N4 comp compre ress ssor or (c) (c) N2 comp compre ress ssor or (d) (d) N1 comp compre ress ssor or 23. Cracks may occur in hot section components of a turbine engine if they are marked during inspection with (a) (a) A lead lead pen penci cill (b) Chalk (c) (c) Layo Layout ut dye dye
(d) (d) Any Any of the the abo above ve 24. When starting a turbine engine, a hung start is indicated if the engine. (a) Exhaust Exhaust gas tempera temperature ture exceeds exceeds specifie specified d limits limits (b) Falls Falls to to reach reach idle idle RPM RPM (c) RPM exceeds exceeds specifi specified ed operati operating ng speed speed (d) Pressure Pressure ratio ratio exceeds exceeds specified specified operating operating limits limits 25. What are the two main sections of a turbine engine for inspection purposes? (a) Combus Combustio tion n and and exhau exhaust st (b) (b) Hot Hot and and col cold d (c) Compre Compresso ssorr and and turbi turbine ne (d) Combus Combustio tion n and turb turbine ine 26. What are the two functions elements in a centrifugal compressor? (a) Turbin Turbinee and and compr compress essor or (b) Compre Compresso ssorr and manif manifold old (c) Bucket Bucket and expand expander er (d) Impell Impeller er and and diffu diffuser ser 27. What must be done after the fuel control unit has been replaced on a turbine engine? (a) (a) Reti Retime me engi engine ne (b) Recalibra Recalibrate te the the fuel fuel nozzles nozzles (c) (c) Retr Retrim im the the eng engin inee (d) Rechec Recheck k the flame flame patt pattern ern 28. What is the most satisfactory method of attaching turbine blades to turbine wheels? (a) The fire-t fire-tre reee desig design n (b) The tong tongue ue and and groove groove design design (c) High temp high strength strength design design (d) Press Press fit method method 29. A turbine engine compressor which contains vanes on both sides of the impeller is a (a) Single Single entry entry centrifuga centrifugall compresso compressor r (b) Double Double entry entry centri centrifugal fugal compre compressor ssor (c) Double Double entry entry axial axial flow flow compre compressor ssor (d) Single Single entry entry axial axial flow flow compress compressor or 30. What is the first engine instrument indication of successful start of a turbine engine? (a) A decrease decrease in the exhaust exhaust gas tempera temperature ture (b) A rise rise in in the the engine engine fuel flow (c) A decreas decreasee in the the engine engine pressu pressure re ratio ratio (d) A rise in the the exhaust exhaust gas gas temperatu temperature re 31. Fuel before entering kinto fcu it encounter a course filter (a) The course course filter protects metering metering section section against against damage by contamination contamination (b) This filter filter has by pass provision and permit continued operation operation with unfiltered unfiltered fuel (c) This filter filter is self cleaning cleaning type 32. During boroscope inspection (a) Engine Engine should should be cold cold (b) All boroscope plug plug on the engine should should be in failed failed back in same place place after completion completion of job (c) Engine Engine should should be be rotated rotated thro N2 pad pad (d) All All above above to be be done done 33. Engine fail to start to restart engine
(a) (b) (c) (d)
Recycle Recycle the the fuel shut off off lever lever to restar restartt Shut off fuel fuel and ignition and and dry motor engine engine for 15 sec before before attempting to to restart Engine Engine star startt again again after after 30 sec sec Starte Starterr must must be replac replaced ed
34. During starting if engine over temp beyond specified limit. (a) Engine Engine should should be cooled cooled down and and restarte restarted d (b) Engine Engine compressor compressor borosco boroscope pe to be done before startin starting g (c) Immediate Immediately ly shut down down engine and and determine determine cause cause of over temp temp (d) Carry out in situ hot section section inspection and find out cause of over temp before before attempting to restart
35. Anti static leak valve provided in some lubricating system in turbine engine (a) To mainta maintain in pressure pressure in oil oil system system (b) To main maintai tain n oil line line full full (c) To help help cold cold starti starting ng of engin enginee (d) To prevent prevent flooding flooding of gear gear box after engine engine shut shut down 36. Starting egt high on turbine engine (a) (a) Idle Idle mix mixtu ture re lea lean n (b) (b) Ambi Ambien entt temp temp low low (c) VSV VSV riggi rigging ng not not corre correct ct (d) We Weak ak spark spark on igni igniter ter 37. Reciprocating engine fuel injection carburetor not developing full power may be due to (a) Prope Propelle llerr balanc balancing ing out out (b) Carburet Carburetor or idle RPM RPM adjustmen adjustmentt not correct correct (c) (c) AMC AMC defe defect ctiv ivee (d) Cylinder Cylinder head coolin cooling g fin cracked cracked 38. On turbine engine cruise egt high (a) (a) Flt Flt idle idle RPM RPM hig high h (b) Incorr Incorrec ectt throttle throttle rigin riging g (c) Inter Inter stage stage bleed bleed valve valve stuck stuck open open (d) Fuel Fuel tempe temperat rature ure high high 39. Carburetor mounting bolt loose flange crack (a) Will Will cause cause rich rich mixtu mixture re tall tall (b) Accel Accelera eratio tion n poor poor (c) Overheati Overheating ng of cylin cylinder der and and power power hors hors (d) Engine Engine wil willl not start start 40. Reciprocating engine is shut down by (a) By puttin putting g fuel shut shut off off valve valve to off off position position (b) By putting putting igniti ignition on s/w to to OFF positi position on (c) By putting putting mixtur mixturee controls controls lever lever to idle cut of positio position n (d) (d) None None of of the the abov abovee 41. What are the self-igniting temperatures of kerosene? (a) 6500 C (b) 7500 C (c) 4280 C (d) 8500 C
42. Specific fuel consumption is checked during (a) Take off (b) Climb (c) Cruise (d) Landi nding 43. Calorific valve is measured (a) (a) In hors horsee pow power er (b) BTU/IB /IB (c) (c) Lbs Lbs /Ga /Gall llon on 44. While rigging power lever one important to check is conditioning (a) If out of limit limit engine engine will will have have rich rich due out out (b) If limit of cushion is within within limit internal internal stop will will not allow to to over boast engine engine (c) Cushion of power power lever assure that that will not only be able to obtain take off power but also additional power lever movement during emergency (d) Cushion of power power lever is given given to have smooth and and free operation and to get maximum maximum power. 45. The active clearance control portion of an eec system aid turbine engine efficiency by (a) Adjusting start vane position according according to operating condition condition and and power requirement (b) Ensuring compressor compressor and turbine turbine blade to the engine engine laseing clearance are are kept a minimum minimum by controlling case temperature (c) Automatically Automatically adjusting adjusting engine engine spaced spaced to maintained a desire desire EPR EPR 46. Fuel flow indicator needle is inter by (a) A mecha mechanic nical al gear gear tra train in (b) Direct Direct couplin coupling g to motor motor shaft shaft (c) (c) Magn Magnet etic ic link linkag agee (d) A friction friction clutch clutch on motor motor shaft shaft 47. Combustion efficiency of jet engine is primary function (a) Chemic Chemical al compos compositi ition on of fuel fuel (b) Combusti Combustion on chember chember designs designs (c) (c) Visc Viscos osit ity y of fuel fuel (d) (d) Flam Flamee spee speed d 48. Oil pressure gauge oscilate constantly (a) Leaki Leaking ng oil oil per line line (b) (b) Dirt Dirty y fil filte ter r (c) Indica Indicatio tion n needle needle loos loosee (d) Reducer Reducer in oil line line to indicato indicatorr partially partially clogged clogged
49. Which of the following turbine fuel filters has greatest filtering action action (a) Micron (b) (b) Wine ine mesh mesh (c) (c) Wa Wafe ferr sene seneen en (d) (d) Stac Stack k char charco coal al 50. What should be checked/changed to ensure the validity of turbine engine perfomance check of alternate fuel is used? (a) Fuel Fuel sp gravit gravity y adjust adjustmen mentt (b) Maximu Maximum m RPM RPM adjust adjustme ment nt
(c) EPR EPR KG gaug gaugee calibr calibrati ation on (d) 51. MIL F- 4624A. ATF – JP – 4 Fuel commonly used on gas turbine engine because (a) High High calor calorifi ificc value value of fuel fuel (b) Specific Specific gravity gravity and vapour vapour pressure pressure low low (c) Good Good lubrica lubricatio tion n properti properties es (d) (d) All All abov abovee 52. Which type of fuel control is used on most turbine engine? (a) (a) Mech Mechan anic ical al (b) Hydro Hydro mechan mechanica icall (c) (c) Elec Electr tron onic ic (d) Elect Electrom romech echani anical cal 53. What are the main input parameters in fuel controller unit monitors fuel flow (a) Compressor inlet pressure compressor RPM and turbine turbine inlet inlet pressure pressure (b) Compressor inlet pressure pressure compressor compressor RPM RPM compressor compressor pressure ratio (c) Compressor inlet temperature burner pressure, pressure, tail pipe pipe temperature temperature (d) Compressor inlet pressure, burner pressure and compressor compressor RPM RPM 54. Which type of engine driven fuel pump are mostly used on turbine engine (a) (a) Vane Vane tyup tyupee (b) Double Double gear gear element element (Series) (Series) (c) (c) Cent Centri rifu fuga gall pump pump (d) Double Double gear gear eleme element nt (para (parallel) llel) 55. Which component in FCU prevent compressor stall during acceleration (a) Compressor inlet temperature temperature sensor and turbine inlet inlet temperature temperature sensor sensor (b) By adjusting adjusting high differe differential ntial pressure pressure across across throttle throttle valve (c) By adjustin adjusting g forward forward thrust thrust stop stop and idle idle RPM (d) By a mase stop positioned by three dimensional cam which is is rotated by signal signal proportional to engine speed and translated by signal proportional to CIP
56. What are the positions of pressurizing and dump valve when engine is shut down? (a) Pressuri Pressurizati zation on valve valve and dump dump valve valve open open (b) Pressuri Pressurizati zation on valve closed closed and and dump open open (c) Pressuri Pressurizati zation on valve valve open and and dump dump closed closed (d) Pressuri Pressurizati zation on valve closed closed and and dump closed closed 57.Where flows divider is located (a) In simp simplas lasee fuel fuel nozz nozzle le (b) In the the fuel fuel manifo manifold ld (c) Near pressuriz pressurizing ing and and dump dump valve valve (d) In dupl duplex ex fuel fuel nozzle nozzle 58. What are the causes of hung start? (a) HP fuel fuel shut shut off valve defectiv defectivee (b) Defectiv Defectivee compressor compressor inlet inlet pressure pressure sensor sensor (c) Burner Burner pressur pressuree line leakin leaking g or cracke cracked d (d) (d) Abov Abovee all all (e) 59. What are the causes of start exhaust gas temperature high? (a) Fuel Fuel pump boos boostt stage stage failu failure re (b) Compresso Compressorr pressure pressure ratio ratio prob prob defective defective
(c) Start Start fuel fuel flow flow high high (d) Variable Variable stator stator vane vane stuck stuck open 60. Under which of following conditions will be trimming of turbine engine will be most accurate? (a) Low mois moistur turee and tail tail wind wind (b) Aircraft Aircraft should should be parked parked in cross cross wind and high high humidity humidity (c) All fuel fuel tank must must be full full and rear rear cargo cargo ballasted ballasted (d) Aircraft parked parked engine facing facing wind and after engine warmed warmed go stabilize stabilize temperature temperature 61. What term is used to describe a permanent and cumulative deformation deformation of the turbine blades of turbojet engine? (a) Stre tretch tch (b) (b) Elon Elonga gati tion on (c) (c) Dist Distor orti tion on (d) Creep 62. Which of the following can cause fan blade shingling in a turbofan engine? (a) (a) Engi Engine ne ove overr spee speed d (b) Engine Engine over over tempe temperat rature ure (c) Large Large rapid rapid thrott throttle le (d) FOD
63. Compressor stall is caused by (a) A low angle of attack attack airflow airflow through through the first first stages of compress compression ion (b) A high angle angle of airflow airflow in the through the first stages stages of compression compression (c) A high velocity velocity airfl airflow ow in the the engine engine inlet inlet (d) Rapid Rapid engine engine deceler decelerati ation on 64. A condition known as hot streaking in turbine engine is caused by (a) A partia partially lly clogged clogged fuel fuel nozzle nozzle (b) Misaligne Misaligned d combustio combustion n liner liner (c) Uneven Uneven burn burner er can can coolin cooling g (d) Excess Excessive ive fuel fuel flow flow 65. How many igniter are normally used on a turbine engine having burner cans? (a) One (b) Two (c) Three (d) Nine 66. Which of the following is used to minotor the mechanical integrity of the turbines as well as to check engine operating conditions conditions of a turbojet engine? engine? (a) Engine Engine oil pressu pressure re (b) Engine Engine gas gas temper temperatu ature re (c) Engine Engine oil oil temp temper eratu ature re (d) Engine Engine pres pressur suree ratio ratio 67. Which of the following can inspect and approve an engine major repair for return to service? (a) Certific Certificated ated mechanic mechanic with with airframe airframe and power power plant ratings ratings (b) Certific Certificated ated mechan mechanic ic with a power power plant ratings ratings (c) Certific Certificated ated mechanic mechanic with with inspection inspection authoriza authorization tion (d) Designed Designed mechanic mechanic examiner examiner 68. Hot spots in the combustion section of a turbojet engine are possible indicators of
(a) (b) (c) (d)
Foreig Foreign n objec objectt damag damagee Fault Faulty y ignit igniter er plug plugss Dirty Dirty comp compres ressor sor blad blades es Malfunct Malfunctionin ioning g fuel nozzles nozzles
69. The fuel flow in the combustion section of a turbojet engine are possible indicators of (a) (a) Fuel Fuel mass mass-f -flo low w (b) (b) Fuel Fuel vol volum umee flow flow (c) Engine Engine burne burnerr pressu pressure re drop drop (d) Fuel Fuel visco viscosit sity y flow flow
70. Which of the following conditions is usually not acceptable to any extent in turbine blades? (a) Cracks (b) Nicks (c) Pits (d) Dents 71. Which of the following I the ultimate limiting factor of turbojet engine operation? (a) Compresso Compressorr inlet inlet air temperatu temperature re (b) Compresso Compressorr outlet outlet air air temper temperatur aturee (c) Turbin Turbinee inlet inlet temper temperatu ature re (d) Burner Burner can pressu pressure re 72. The oil used in reciprocating engine has a relatively high viscosity due to (a) The reduced ability ability of thin oils to maintain maintain adequate film strength at altitude altitude (reduced (reduced atmosphere pressure) (b) The relati relatively vely high rotati rotational onal speeds speeds (c) Its lower lower oxidation oxidation rate rate at elevated elevated tempera temperature ture (d) Large Large clearances clearances and and high operating operating temper temperatur aturee 73. The type of lubricating oil that is used in a turbine aircraft engine is (a) (a) Synt Synthe heti ticc (b) (b) Petr Petrol oleu eum m (c) 50-50 blend blend of petro petroleum leum and and synthet synthetic ic (d) 30-70 blend blend of of petroleum petroleum and and synthet synthetic ic 74. The viscosity of a liquid is a measure of its (a) Resist Resistanc ancee of of flow flow (b) Rate of change change of internal internal friction friction with with change in temp density density (c) Densi nsity (d) Ability Ability to transmit transmit force force 75. In a reciprocating engine oil system, the temperature bulb senses oil temp (a) And indic indicates ates the average average oil oil temp temp (b) At point point after the the oil has passed passed through through the oil oil cooler cooler (c) While While the oil is is in the hottes hottestt area of the the engine engine (d) Immediate Immediately ly before before the oil enters enters the oil oil cooler cooler 76. What is the purpose of an augmenter used in some reciprocating engine exhaust systems? (a) To reduce reduce exhaust exhaust back pressure pressure (b) To aid aid cooli cooling ng the the engine engine (c) To assist assist in in displaci displacing ng the exhaus exhaustt gases gases (d) To augment augment the surface surface area area of the exhaust exhaust extension extension
77. How do cowl flaps aid in cooling a horizontally opposed aircraft engine? (a) Furnishes Furnishes ram air air to the the engine engine cylinder cylinderss (b) Directs Directs air throu through gh the engine engine cylinde cylinders rs (c) Streml Stremline iness the the engi engine ne (d) Controls Controls the the amount of air air passing passing around around the engine engine 78. Power recovery turbine used on some reciprocating engine are driven by the (a) Exhaus Exhaustt gas gas pres pressur suree (b) (b) Cran Cranks ksha haft ft (c) Veloc Velocity ity of of the exhau exhaust st gases gases (d) Fluid Fluid dri drive ve coup couplin ling g 79. A bend colling fin on an aluminium cylinder head (a) Will Will cause cause reject rejection ion of the cylin cylinder der (b) Should Should be sawed sawed off and and filed filed smooth smooth (c) Should Should be left left alone alone if no no crack crack has formed formed (d) Should Should be stop drilled drilled or a small small radius radius filed filed at the point of the the bend 80. If the turbo supercharger waste gate is completely closed (a) None of the the exhaust exhaust gases are are directed directed through through the turbine turbine (b) The manifol manifold d pressure pressure will be lower lower than than normal normal (c) The turbo turbo supercha supercharger rger is in in the OFF OFF position position (d) All the exhaus exhaustt gases are are directed directed through through the turbine turbine 81. How do the turbines, which are driven by the exhaust gases of a turbine compound engine, contribute to total engine power output? (a) By driving driving the cranksh crankshaft aft through through suitabl suitablee couplings couplings (b) By causing causing the exhaust back pressure to remain below below atmosphere atmosphere pressure at all operating operating altitudes (c) By driving the supercharger supercharger thus relieving relieving the engine of the the super charging charging loud (d) By converting the the latent heat energy of the exhaust gases into thrust by collecting collecting and accelerating them 82. Corrosive valve clearance results in the valves opening (a) Early and closing early (b) Late Late and and closi closing ng early early (c) Early Early and closin closing g late late (d) Late Late and and clos closing ing late late
83. Metallic particles are found on the oil screen during an engine inspection (a) It is an an indication of normal engine wears wears unless the particles are are nonferrous (b) The cause should be identified identified and corrected before before the aircraft aircraft is released for flight (c) It is an an indication of normal engine wear wear unless the deposit. Exceeds Exceeds a specified specified amount (d) It is an indication indication of normal engine wear unless unless the particles particles show ferritic ferritic content (respond (respond to a magnet) 84. Excessive valve clearance will cause the duration of valve opening to (a) Increase Increase for for both intak intakee and exhaust exhaust valves valves
(b) Decrease Decreasess for both intak intakee and exhaust exhaust valves valves (c) Decrease Decreasess for intake valves valves and increases increases for exhaust exhaust valves valves (d) Increase Increasess for intake valves valves and decreases decreases for exhaust exhaust valves valves 85. Engine operating flexibility is the ability of the engine to (a) Deliver Deliver maximum maximum horsepow horsepower er at a specific specific altitud altitudee (b) Meet exacting exacting requirement of efficiency efficiency and low low weight per horsepower horsepower ratio (c) Run smoothly smoothly and and give the desire desired d performance performance at all all speeds speeds (d) Expand Expand and contract contract with changes changes in temperatu temperature re and pressure pressure 86. What is an advantages of using metallic fillex exhaust valves in aircraft reciprocating engine? (a) Increase Increased d resistanc resistancee to corros corrosive ive gases gases (b) Increase Increased d strength strength and resista resistance nce to fatigue fatigue (c) Reduced Reduced valve valve operating operating temperat temperature ure (d) Greater Greater resistanc resistancee to deterior deterioration ation at high valve tempera temperature ture 87. Excessive valve clearance in a piston engine (a) Increa Increases ses valv valvee overla overlap p (b) Has no effect effect on valve valve overlap overlap (c) Increa Increases ses valve valve servi service ce life life (d) Decre Decrease asess valve valve overlap overlap 88. The pumping capacity of the scavenger pump in a dry-sump aircraft engine’s lubrication system? (a) Is greater greater than than the capacity capacity of of the oil suppl supply y pump (b) Is less than than the capac capacity ity of the the oil supply supply pump pump (c) Is usually usually equal equal to the capacit capacity y of the oil supply supply pump pump in order (d) Varies according according to the oil supply supply tank capacity capacity and not according according to the oil supply pump capacitys
89. The economizer system of a float type carburetor performs which of the following functions? (a) It supplies and regulates the fuel required for all engine speeds speeds below cruising (b) It supplies supplies and regulate regulatess the fuel required required for all engine engine speeds speeds (c) It supplies sand regulates regulates the additional additional fuel required required for all speed above above cruising (d) It regulates regulates the fuel required for all engine speeds and all all altitude.
ALL INDIA AME VELFARE ASSOCIATION (REGD) ENJAB, KARBLA LODHI ROAD NEW DELHI- 110003 AME L.C. FROM EXAM. QUESTION PAPER
SESSION- JUNE 1996
PAPER III (JET ENGINE) OBJECTIVE TYPE 1. Fig. Shown trend analysis the defect defect indicated is (a) N2 indi indicat cator or defec defectiv tivee (b) Bleed Bleed valve valve stru struck ck in open open (c) Bleed Bleed valve valve stru struck ck in clos closee (d) (d) All All are are wron wrong g 2. In a turbo prop engine for a given EPR (a) EGT EGT rings rings wit with h altitu altitude de (b) EGP decreased decreased with altitudes altitudes (c) Altit Altitude ude has has no effe effect ct on EGT EGT (d) (d) All All are are corr correc ectt 3. Fig. Shown a simple torque meter which in the torque sensing component (a) A (b) A B & C (c) B & C (d) E 4. Axial compressor the blades becomes shorter at the rear stages (a) To incre increases ases the velocity velocity of air air (b) To prevent prevent high speed speed stall stall and surge surge 5. CSD input RPM is 5800 while output RPM in 6000 (generator) the CSD is working as (a) (a) Hyd. Hyd. Moto Motor r
(b) Pump (c) Direct Direct straight straight drive drive to genera generator tor is working working as as 6. NTCS regarding the r-v graph (a) Stage Stage betwee between n 1 & 2 is compressi compression on (b) Stage Stage between between 2 & 3 is compre compression ssion (c) Stage Stage betwee between n 3 & 4 is compressi compression on (d) All All of the the above above are are corre correct ct
7. The fig shown a thermocouple probo MTCS (a) A is eve (b) A is alumal alumal and and is color color codeddgra codeddgraph ph (c) (c) A a thud thudss mag magne nett (d) All All above above are correc correctt 8. A helicopter on rescue mission is hovering. The EGT is 700 0 C when the power is increased (a) EGT EGT wil willl incr increas eased ed (b) EGT EGT wil willl decre decrease ased d (c) EGT will will first first decreased decreased upto certain power power and train increases increases 9. A turbo shaft produces max. power (a) (a) At take take off off (b) At minim minimum um conti continge ngency ncy (c) At max. max. contin contingen gency cy (d) (d) Max Max cont contin inuo uous us 10. A turboshaft produces max power (a) Below elow PSI (b) (b) Abov Abovee 20 PSI PSI (c) (c) Betw Betwee een n 10 – 18 18 PSI PSI (d) None 11. Most commonly used cleaning agent for turbine blades (a) Kerose rosene ne (b) Telchoroe Telchoroethyl thylene ene eloctroly eloctrolyto to (c) (c) Any Any one one can can be used used 12. Turbine engine components are never manufactured by (a) Argon Argon or plasma plasma are are weldi welding ng (b) (b) Gas Gas weld weldin ing g (c) Elec Elec resis resistan tance ce weldi welding ng 13. MTCS regarding the goar type pump (a) A partia partiall vacuum vacuum is is create created d at A (b) Oil trapped trapped between between gear tooth’s tooth’s and pump pump antiwar antiwar housing is 14. As per Bernoulli principal if air passes through a convergent tube (a) Pressure Pressure will will increa increase se and velocity velocity decrease decrease (b) Vel Vel increa increase se & pr. decr decreas easee (c) Vel. Incre Increase ase & pr. Decrea Decrease se with decre decrease ase temp temp
15. MTCS regarding thrust reversor (a) Mixed Mixed exhaust exhaust type engine engine need need only one reversor reversor (b) In high by pass pass turbofans reversor reversor of secondary air air is more effective effective than that that of primary air (c) Both primary primary and and secondary secondary flow are reverse reversed d by using two reversor reversor (d) All All of the the above above are are corre correct ct 16. Fig. Annular combustion chamber MTCS (a) This type type of chamber chamber given given more mechanic mechanical al strength strength (b) Makes Makes well utiliz utilization ation of of available available space space (c) Side effici efficient ent combustio combustion n act reduce reduce power & high high altitude altitude (d) (d) All All are are corr correc ectt 17. Resin used for engine cowlings (a) Epoxy (b) Thermo Thermopla plasti sticc resin resin (c) (c) Ther Thermo mose sett resi resin n (d) (d) Hybr Hybrid id mat matri rix x 18. Inlet for coolings air for the first stage turbine blades is from (a) (a) Gill Gill hole holess (b) (b) Blad Blades es roo roott 19. Max forward thrust is produced by (a) Diffus ffuseer (b) (b) Comp Compre ress ssor or (c) (c) Comb Combus usto tor r (d) (d) Exha Exhaus ustt unit unit 20. Maxi energy jet blast is provided by (a) (a) Turb Turbop opro rop p (b) (b) Turb Turbo o shaf shaftt (c) Turbo urbo fan (d) (d) Turb Turbo o jet jet 21. Magnesium is uses to east compressor case because of (a) Good Good case case prope properti rties es of Mg (b) No compli complicate cated d prosses prosses are are involve involved d 22. Mandatory fuel additive is (a) (a) Fung Funglc lcid idee (b) Anticorr Anticorrosive osive anti-oxid anti-oxidisin ising g (c) (c) Anti Anti-- ici icing ng (d) (d) All All abov abovee 23. The figure shown in typical igniter plug for turboprop engine. Mark the correct statement regarding it (a) The holes are provided provided for for coolin cooling g (b) The body body provide providess positive positive curre current nt path (c) All All the above above are are correc correctt 24. Oil system generally used on most modern turbine engine is (a) (a) We Wett sum sump p typ typee (b) (b) Dry Dry sum sump p typ typee (c) Low pressu pressure re syste system m (d) High High pres pressur suree syste system m
25. Front bearings supporting the compressor drive shaft in a small business jet is (a) Roller (b) Hall (c) (c) Tape Taperr roll roller er (d) Depends Depends on the radia radiall longs impene impened d on engine engine 26. In the given figure of oil filter (a) A & B are are inle inlett parts parts (b) D is filter drain drain for maintenance purpose the filter becomes becomes slogged slogged (c) All All the above above the the corre correct ct 27. In the figure of nozzle diaphragm assembly the splinge are provided are provided for (a) (a) Lock Lockin ing g spr sprin ing g (b) (b) Labr Labry y in the the sea seall 28. In the figure the rain locking part is (a) A (b) B (c) Both oth A & B (d) None 29. Rotation pad on Accessory drive gearbox is provided for (a) (a) For For N2 N2 rot rotat atio ion n (b) Alternat Alternatee techno-gen techno-generat erator or (c) Balanc Balancing ing of of fan fan can be be done done (d) All All the abov abovee are corr correct ect 30. Methyle browide fig extinguisher has been accidentally discharged to return the engine into service: (a) Wa Wash sh the engi engine ne into into servic servicee (b) Wait for for atleast atleast 3 hrs hrs so that the extinguishing agent evaporation evaporation (c) Operate Operate the the engine engine at idle low power power (d) Carry Carry out electrol electrolytic ytic compre compressor ssor wash wash 31. At ram recovery point (a) Pressure Pressure increas increasee neutralizes neutralizes the friction friction losses losses in inlet 32. In the given 1 – 7 graph (a) One event is at constant constant volume volume (b) Shown Shown line is the compressio compression n stroke stroke (c) All All the above above are are correc correctt 33. In the given figure of ignition system, the (a) C4 is a tank tank capac capacito itor r (b) L-c circu circuit it is radio radio noise noise filter filter (c) S is is a buler buler capa capacit citor or (d) All All the abov abovee are corr correct ect 34. The point of height pressure in the gas turbine engine is (a) (a) Comp Compre ress ssor or (b) (b) Diff Diffus user er (c) Turbi urbine ne (d) (d) Exha Exhaus ustt nozz nozzle le 35. Mark the correct statement (a) In the stator stator the pressure pressure of the air increase increase and velocity velocity a decreases decreases (b) The velocity loss is restored by the angular deflection of the air through through rotor
(c) Inlet Inlet guide vane vane inlet inlet & exhaust exhaust velociti velocities es are equal equal (d) All All the abov abovee are a corr correct ect 36. In the APU (a) Turbine Turbine blade bladess are are made made of titanium titanium (b) APU has has reverse reverse flow flow combusti combustion on chamber chamber (c) It is supported supported on the the plain journal journal bearings at the front front and roller roller bearing bearing (d) (d) None None of of the the abov abovee 37. Pour point is expressed in (a) Decima cimall (b) (b) Cent Centii stro stroke ke (c) Poise (d) Degree gree F 38. Win the given figure point (a) Provide Provide for geroscopi geroscopicc inspec inspection tion (b) Remains Remains locked locked during during the engine engine opera operation tion (c) (c) To fix fixed ed sta start rter er (d) To provide provide for for manual manual crank crank of gas turbine turbine engine engine
39. The hardware used in gas turbine engine, which bolt is cd. Plated. (a) (a) Both Both A and and B (b) A (c) B only (d) (d) All All A B and and C 40. Mark the correct statement (a) Governme Government nt spill valve valve acts as as a safety relief relief valve valve (b) Engine Engine speed speed governor governor acts acts as a relief relief system system (c) Both Both a and and b are are corr correc ectt (d) None of the the above above are are correc correctt • •
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In is only for AIAMESWA members. Members can obtain the question papers from their respect are regional local secretaries by paying normal photocopy charge. Question papers can be obtained from the central office directly, New Delhi on payment of Rs. 10/- for each paper through DD in favour of the AIAMESWA, AIAMESWA, New Delhi. To increase participants in preparation of the question papers, the association has decided to furnish the copy of the question papers fuel of cost to the members who send at least so objective and 4 subjective type question to us.
41. In the fuel control unit of hydro mechanical system if the engine all elevators without throttle movement, it is due to (a) (a) Less Less of spee speed d sens sensee (b) CIT CIT soon sooner er failur failuree (c) CIS de dense nse (d) (d) All All are are corr correc ectt 42. The gearbox gasing is made of (a) Alumi uminum num (b) (b) Magn Magnes esiu ium m (c) Steel
(d) Nicke ckel 43. Compressor air leakage in a turbine of an engine is noted by (a) (a) Rise Rise in RPM RPM (b) Rise Rise in vibra vibratio tion n (c) (c) Rise Rise in EGT EGT (d) (d) All All the the abov abovee
44. Pintle valve are used in (a) (a) Vane Vane type type pump pump (b) Radial Radial piston piston pump pump (c) (c) Axia Axiall pist piston on pum pump p (d) (d) Guro Guroto torr pump pump 45. With the change in the altitude or forward speed of the a/c the our capsule assembly in the fuel control unit in (a) Capsul Capsulee assemb assembly ly expand expanded ed (b) Capsule Capsule assembly assembly compresse compressed d (c) No changed changed in capsule capsule assembly assembly (d) (d) None None of of the the abov abovee 46. Match the following component with their method of processing Engine inlet camshaft nozzle (a) (b) (c) (d)
Spin casting Send casting Spin casting Send casting
Sinning Forging Forging Forging
EC ECM EC ECM EC ECM EB EBM
turbine
ECM EBM EBM EBM
47. During operation of the engine equipped with water injection system the watering of the coolent to the system is (a) Due to to atmosp atmospher heree pressu pressure re (b) Due to altit altitude ude chan change ge (c) Selec Selected ted by the pilot pilot (d) (d) None None of of the the abov abovee 48. Mark the correct statement (a) Humidity Humidity has has formally formally large large effect on the reciproc reciprocating ating engine engine (b) Humidity Humidity has has loss effect effect on the gas reciprocati reciprocating ng engine (c) Both jet and reciprocating reciprocating engine are are equally affected by the humidity effect. (d) None of the the above above are are correc correctt 49. Mark the correct statement (a) Starter Starter drive drivess the N2 compr compressor essor (b) Starter Starter drives drives the N1 N1 compress compressor or (c) Quill shaft shaft breaks breaks if the the sessing switch fails fails to disengage the starter (d) (d) A & C are are corr correc ectt 50. In a gas turbine engine, velocity type and accelerometer type vibration indicators are used, in which: (a) Velocity type reads reads in VOLTs and accelerometer accelerometer type type in COULUMBS (b) Velocity Velocity type type is less reliable reliable than than accelerome accelerometer ter type
51. The lowest TSFC is of (a) (a) Turb Turbof ofan an eng engin inee (b) (b) Turb Turboj ojet et engi engine ne (c) (c) Turb Turbop opro rop p engin enginee (d) Turbos Turboshaf haftt engine engine 52. The purpose of the inlet guide vanes is (a) To incr increas easee the pressu pressure re (b) To incre increase ase the the veloc velocity ity (c) To direct direct the air without without changin changing g the pressure pressure & velocity velocity 53. When anti-icing system is switched ON (a) (a) TGT TGT inc incre reas ased ed (b) (b) EPR EPR decr decrea ease sed d (c) (c) N2 decr decrea ease sess (d) All All the abov abovee are corr correct ect 54. When fire extinguisher bottle is discharged due to high temp (a) Red disc disc is is blow blown n out out (b) Yello Yellow w disc disc is blown blown out out (c) It is is indicat indicated ed in pressure pressure gauge gauge (d) (d) None None of of the the abov abovee 55. Identify the following symbols: (a) Motor Relief valve (b) Pump Relief valve (c) Pump Heat exchanger (d) Motor Relief valve
cooler Heater heater heater
pressure gauge pressure gauge temperature gauge temperature gauge
56. The pitch movement of the propeller blade is controlled by a hydraulic servo piston the increase of oil pressure in the servo makes the propeller blade to (a) Low pitch pitch rotati rotation on (b) High High pitc pitch h rotat rotation ion (c) (c) Run Run at at low low RPM RPM (d) High High pitch pitch with with high high RPM RPM 57. The firing end of the low voltage igniter should be (a) Cleare Cleared d using using dry dry cloth cloth (b) Cleaned Cleaned using using fibre fibre brist bristle le brush brush (c) Any one one the the above above could could be be used used (d) (d) Neve Neverr cle clean aned ed
58. Mark the correct statement with respect to engine bearings (a) Atleast Atleast one ball ball bearing bearing must be in in the front of the the engine engine (b) Deep groove groove thrust thrust bearing bearing support support axial axial and radial radial loads (c) Load carrings carrings capacity of roller bearings is better than the ball bearing bearing (d) (d) All All the the abov abovee 59.The free turbine turboprop engine has different control levers is the cockpit the power lever directly controls the (a) Gas Gas genera generator tor spee speed d (Ng) (Ng)
(b) Power Power turbi turbine ne speed speed (Nf) (Nf) (c) Prope Propelle llerr govern governor or (d) (d) All All the the abov abovee 60. The compleate control of a modern APU is performed by microprocessor based electronic control box. (ECB) the input of the the box is from (a) (a) APU APU anal analog og inp input ut (b) As in (a) and and APU APU discre discrete te input input (c) Aircr Aircraft aft disc discrat ratee input input (d) Analog and discrete from from APU along along with the signal from aircraft. aircraft. 61. In commercial turbofan power management control (PMC) provides an electronic override of the MEC to correct fan speed which is a function of (a) (a) Powe Powerr leve leverr angl anglee (b) Fan Fan inle inlett pres pressur suree (c) Fan Fan inlet inlet temper temperatu ature re (d) (d) All All the the abov abovee 62. Modern jet engine uses a accelerometer to pick up engine vibration the indicator must have (a) (a) Char Charge ge ampl amplif ifie ier r (b) Voltage Voltage to curre current nt conver converter ter (c) (c) Curr Curren entt limi limite ter r (d) (d) Volt Voltag agee limit limiter er 63. A free turbine turbo shaft is running at higher RPM there is loss of oil pressure the probable cause is (a) The relief relief valve struck struck in closed closed posit position ion (b) The relief relief valve struck struck in open open positio position n (c) (c) Filt Filter er clog clogge ged d (d) Oil Oil spray spray jet clogge clogged d 64. When Pt2 is blocked due to ice formation then the EPR gauge will (a) Over ver re read (b) (b) Unde Underr rea read d (c) Read ead zer zero o 65. Which one of the following scale is high pressure system (a) Lip (b) Cup (c) (c) Carb Carbon on rubb rubbin ing g (d) (d) All All the the abov abovee 66. When oil filter particle dissolves fully in Aquous solution of ammonium nitrate, the particle is (a) Tin (b) Cadmi admiu um (c) (c) Alum Alumin iniu ium m (d) Silver lver 67. The figure given below is or APU fitted in modern boeling aircraft the air inlet in the figure in (a) C (b) A and B (c) D (d) (d) None None of of the the abov abovee 68. During preflight inspection the crewmember find that the amber deck of the fire warning light appears out this indicates (a) The extingu extinguishin ishing g agent in bottle bottle is over over pressurize pressurized d
(b) The extingu extinguishin ishing g agent in dischar discharged ged due to over temp. temp. (c) The extingu extinguishin ishing g agent in the the bottle is is at low pressure pressure (d) The extingui extinguishing shing agent agent in discharged discharged due to cook pit control control 69. When the air starter over speeds due to failure of internal switch mechanism (a) The engine engine RPM contin continues ues to rise until until it reache reachess idle RPM (b) The volume to starting starting air automatically automatically decrease to overcome the situation (c) The drive drive shaf shaftt break breakss (d) Any the stated stated above above may may happe happen n 70. Engine operating instructions are OK except flam out during deceleration the most likely cause is (a) Accelerat Acceleration ion decelera deceleration tion valve valve (b) Maximum Maximum flow valve setting setting (c) Minim Minimum um flow flow valve valve sett setting ing (d) Gover Governor nor settin setting. g. 71. At cruise condition the pilot observes fluctuation of EGT about 30 but the EPR and RPM are study. The part of engine defective is (a) Combus Combustio tion n chambe chamber r (b) Pyrom Pyromete eterr system system (c) Turbi urbine ne (d) (d) None None of of the the abov abovee 72. The graph indicates the specified fuel consumption at standard level pressure is of (a) (a) Turb Turbo o prop prop (b) (b) Turb Turbo o jet jet (c) Turbo urbo fan (d) All of of the above above will will have have same graph graph 73. The figure is of air intake having electrical anti icing (a) Outer Outer surface surface is is continual continually ly heated heated (b) Forward Forward surface surface is cycli cyclicall cally y heated heated (c) Welding Welding will will reduce reduce the resistance resistance of the the elements elements (d) There There is no overhe overheat at protecti protection on on ground ground 74. The centrifugal compressor is shown (a) A (b) B (c) C (d) (d) None None of of the the abov abovee 75. In the figure (a) Fl is the the fuel manifo manifold ld supplied supplied fuel fuel at starting starting (b) F2 is the the fuel fuel supplied supplied for for all the points points (c) The airflo airflow w blow away and carbon carbon deposit depositss (d) All All the abov abovee are corr correct ect 76. Mark the correct statements (a) Whittle Whittle burner burner min. min. pressur pressuree loss loss (b) Annu nnular lar (c) Can – annula annularr best best efficienc efficiency y (d) Cannular Cannular – best utiliz utilization ation of availab available le space space 77. Match the following (a) Solenoid (b) Relief valve
-
LP speed governor Fuel pump
(c) Back pr. Valve (d) Annular
-
Spray nozzle Dash feed throttle.
78. Identify the turbine blades: Fir Fir tre tree root oot Fir tree ree root oot BMW holl hollow ow blad bladee De-le e-leve vell bulb bulb ----------------------------------------------------------------------------------------------------------------------(with lock plate) (with shank seal) (with retaining pin) (with look sc) (a) A B C D (b) B A D C (c) C D A B (d) D C B A 79. In the figure (a) R is the bleed bleed resi resisto stor r (b) R grounds the earth charge of the trigger capacitor capacitor turning each cycle. (c) When When the ignitor ignitor is not triggere triggered, d, R grounds grounds the current current (d) All All the abov abovee are corr correct ect 80. Mark the correct statement with respect of single speed engine shown being more comp. Stage than turbine because. (a) Compresso Compressorr material material is what what before before cannot take take the load (b) It’s differe different nt to get compression compression due to diffusi diffusion on in less stage (c) All All the above above are are correc correctt
ALL INDIA AME STUDENTS WELFARE ASSOCIATION (REGD) AME Lic. Exam. Question paper Session – JUNE 95 Paper – III Subject jet engine (objective) ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------1. Consider forget turbine helicopter engine running at max. gas generator speed any increase of load will (a) (a) Redu Reduce ce NTL NTL onl only y (b) Both Ng and and NTL NTL will will increase increase (c) Bring Bring down down gas gener generato atorr speed speed (d) Increase Increase Ng and decreas decreasee ferr turbine turbine speed speed (NTL) (NTL) 2. Refer the fig. Of turbine disc/blade and mark correct statement (a) Teritiar Teritiary y creep is indepen independent dent of gas temper temperatur aturee (b) The rate of primary creep is always less less than of the secondary secondary creep (c) The middle portion of the blade is exposed to high temp than root and tip of the blade (d) All All the abov abovee are corr correct ect 3. When a turbojet engine operating at steady state max RPM any increase of airmass flow due to inlet variable (a) May increased increased the compressio compression n ratio ratio (b) May decre decrease ase the the compres compression sion ratio ratio.. (c) Not affect affect the the compr compressio ession n ratio ratio (d) (d) None None of of the the abov abovee 4. The following fig shows a electrical tube anti icing system of an enging inlet. (a) Outer Outer surface surface is is continuou continuously sly heate heated d (b) Repairing element by welding welding decreases the the element element resistance resistance (c) Forward Forward eleme element nt is cyclicly cyclicly heated heated (d) There There is no over heat protec protection tion when when the A/C is on the ground ground 5. The principle involved in controlling the fuel flow according to the requirement of he engine? (a) Keeping the delta pressure across the metering valve constant and changing the cross section section of the orific (b) Keeping the constant constant section of the orific constant constant and varying the dolta pressure pressure across the metering valve (c) Sessing the feed back from from RPM and EGT thermocouple and and controlling the fuel through through the electronic controller. 6. Hottest section of the engine is (a) Combuc Combuctio tion n chamber chamber casin casing g (b) H.P. H.P. turb turbine ine casing casing (c) L.P L.P turb turbine ine causin causing g (d) (d) Jet Jet pipe pipe cas casin ing g 7. When CDP sensor fail during cruise condition or high power condition the engine will. (a) Flame lame out out (b) Surge (c) Decel Decelera erate te to idle idle conditi condition on (d) Accelerat Acceleratee to max max power power conditi condition on 8. On a twin spool turbofan engine with electronic TGT limitor (Amplifier) all engine paramotors are fluctuating at max. RPM this is due to malfunction of (a) (a) Ampl Amplif ifie ier r (b) TGT TGT thermo thermocou couple pless storm storm
(c) (c) N1 sen sense serr syst system em (d) Any one of the the abov abovee 9. Mark the correct statement regarding cracks (a) A & B can be detec detected ted by longitu longitudina dinall magnetiza magnetization tion (b) B can be detected detected by either circular circular or longitudinal magnetization (c) C can be be detected detected by circular circular magnes magnesatio ation. n. (d) (d) None None of of the the abov abovee 10. The advantages of the type of injector injector shown in the figure is is (a) Fuel Fuel regulat regulator or not requi require red d (b) Two injec injectors tors are are used used in an an engine. engine. (c) Does not depend depend on rate rate of fuel fuel flow flow (d) All All the abov abovee are corr correct ect 11. In a typical turboshaft free power turbine engine, the FCU basically senses. senses. (a) The power power lever lever governor governor free turbine turbine (b) The power power turbin turbinee (c) The power power lever lever governor governor free turbine turbine throug through h power turbine turbine (d) (d) Gas Gas gene genera rato tor r ESSAY - TYPE 1. A modern aircraft fitted with two turbofan engines is O.K during engine ground run performance. The aircraft was released for flight with instructions to the pilot. During take-off run, there was a jerk with rise in EGT, severe EPR fluctuation and vibration. The pilot aborted the take-off. (a) What What is the cause cause and the the events events took place place in a sequan sequance? ce? (b) What are the critical critical areas to be checked for for the cause and the remedial remedial action. 2.
(a) What will will happen happen if the the P & D valve is struck in open condition condition during starting? (b) What are the functions of straightening vanes of exhaust cone? (c) How the micro organism form in the fuel fuel how they affect affect the fuel system and its components? How they are detected? (d) What are the areas to be checked for high oil consumption? (e) What is the trim balancing?
3. How will you check the serviceability of the following I. LOP switch II. Tacho generator III. Surge bleed valve IV Oil temp. bulb V Thermocouple harness VI RPM pulse pick – up b. Describe the serviceability check of H.E ignition system. 4. In the figure given below (a) Identi Identify fy the parts parts (b) Explain Explain the the purpose purpose of various various parts. parts. a. How will you perform emergency shut down of APU during ground run b. Where are the boroscopic inspection holes are provided in the engine and how and they helpful in monitoring the health of engine? c. What actions you will take during fire warning stall/surge and engine flame out? 5. Titanium should not be cleaned (a) Trich Trichlor lor ethyl ethylene ene (b) Rx 222
6. RD 2490 is (a) Corros Corrosion ion inhibi inhibitor tor (b) (b) Synt Synthe heti ticc oil oil (c) (c) Clea Cleani ning ng agen agentt (d) (d) None None of of the the abov abovee 7. After shut down of engine the boost pump should never be put off until the engine rotor stop this make that the (a) (a) EDP EDP do do not not loos loosee prim primee (b) F & D oper operate ate correc correctly tly (c) (c) Fuel Fuel pump pump life life more more (d) Fuel filter filter operat operation ion is is satisfa satisfactor ctory y 8. In hydro mechanical fuel control if CIT sense fail on hot day then engine (a) Takes Takes more more time time to accel accelerat eratee (b) (b) Run Run at at low low RPM RPM (c) Surge Surge and and EGT EGT may may occu occur r (d) All All the abov abovee are corr correct ect 9. Crack pressure adjustment of P & D valve is at low side (a) Secon Secondar dary y fuel fuel flow flow casier casier (b) High EGT starter starter accel accelerat eration ion (c) Reduce Reduce stall stall margin margin (d) (d) All All the the abov abovee 10. The vibration indicator pick up is mounted in the turbine casing it indication (a) Turbin Turbinee vibra vibratio tion n only only (b) Turbine Turbine and and turbine turbine casing casing vibration vibration (c) Turbine Turbine and compressor compressor vibration vibration (d) (d) All All abov abovee 11. The blades of the compressor are twisted. This make blade (a) More press pressure ure on the the blade blade tip than than the the root (b) More press pressure ure on the the blade blade root than the the tip (c) More pressur pressuree at the middle middle portio portion n of the blade blade (d) (d) None None of of the the abov abovee 12. For the water particle inspection of the fuel the water indicator paste is applied at the bottom of the sample bottle if the water is present in the fuel (a) The past past will will come come to from the bottom bottom (b) The bottom bottom of the the bottle bottle will will be discolour discoloured ed (c) The complet completee sample sample will will be discol discoloured oured (d) (d) None None of of the the abov abovee 13. A turbofan engine produce. A thrust of 9100 lbs, the fuel consumption is 700 Gallon/hr. The SPC will be (a) (a) 0.07 0.07 lb/l lb/lb/ b/hr hr (b) (b) 0.5 0.5 lb/l lb/lb/ b/hr hr (c) (c) 0.6 0.6 lb/l lb/lb/ b/hr hr.. (d) (d) 0.7 0.7 lb/ lb/lb lb/h /hr. r. 14. The diagram is of a single hydraulic actuator for satic vanes the is will be (a) 200 PS PSI (b) 20 PSI (c) 10 PSI (d) 200 200 PSI
15. Compressor blades are not fitted rigidly on the nut there is a slight movement this is done to (a) Provide Provide case case of replacem replacement ent of blade (b) To provide provide relief relief for the the expansion expansion of the blade blade due to heat heat (c) To reduce reduce vibrat vibrational ional stress stress on the the blade blade (d) (d) All All the the abov abovee 14. The baffles plates are incorporated in the oil tank the of this plate is (a) To avoid avoid local turbulen turbulence ce and recircul recirculatio ation n of used of (b) To settle settle down the the foreign foreign particles particles in the bottom bottom (c) They They give give coolin cooling g capaci capacity ty (d) All All the abov abovee are corr correct ect 15. For soap analysis the sample must be collected (a) Within Within ½ an hour hour of the engine engine shutdown shutdown (b) After After enough enough cooling cooling of the the engine engine (c) After After half an an hour of the engine engine showdow showdown n (d) Any time 16. For a given EPR if the OAT decreases the N2 RPM of turbofan engine will (a) Incre ncreaase (b) (b) Decr Decrea ease sess (c) (c) Rema Remain in same same (d) Increase Increasess N2 with with decre decrease ase of EGT 17. If engine fitted with hydro mechanical FCU when speed sense N2 fails during IDLE condition the engine. (a) Flame lame out out (b) Can not not acceler accelerate ate above above IDLE IDLE RPM RPM (c) Accel Accelera erate te to high high power power bottj bottj (d) (d) None None of of the the abov abovee 18. Match the following (a) Threaded (b) Un threaded (c) Greased blank (d) Grease proof paper
(a) Air intake (b) Fuel lines (c) Compressor of take (d) Rubber part
19. Match the following (a) Injector wheel (b) Secondary burner (c) Double cone (d) A square low injector 20. Match the following Differential pr. On vane produces (a) Torque load (b) Bending movement (c) (c) Bend Bendin ing g move move-Ment (d) Torque load.
(a) Simplex (b) Centrifugal (c) Duplex (d) Pre vaporization form.
Aerodynamic force produces pending movement Torque load.
Torque load Bending load.
Angle of incidence Pressure acro &Subsequent stage Vane Reduces increases Increases
increases
increases Increases
constant Reduced
21. Match the following star starti ting ng cont contro roll (a) Droop cam (b) 3D cam (c) 3D cam (d) droop cam
stud study y stat statee cont contro roll acce accele lera rati tion on decr decrea ease sess 3D cam Droop cam 3D cam 3D cam 3D cam Droop cam 3D cam Droop cam Droop cam Droop cam 3D cam 3D cam
22. Match the following (a) Blade rotainor (b) S Sp pacer (c) Spinner road cone (d) mid span shroud 23. Match the following stru struct ctur ural al stability (a) Can annular (b)
(a) In assembly stiffness (b) Radial movement (c) Axial movement (d) Axial stability on rotation
most most effi effici cien ency cy
easy easy insp inspec ecti tion on
annular
For For lowe lowerr no emmision Can annular Double annul
24. If the spring prossure of the P & D valve is weak each (a) The engine engine will will run run at lower lower RPM RPM (b) The engine engine will run at at higher higher RPM RPM (c) (c) High Higher er EGT EGT (d) (d) All All the the abov abovee 25. The transformation of kinetic energy in to pressure energy is NIL in which type of engine (a) (a) Turb Turbo o prop prop (b) (b) Turb Turbo o jet jet (c) (c) Turb Turbo o sha shaft ft (d) (d) By pass passed ed fan fan 26. Bell mouth compressor is used in engine calibration on ground because (a) The duct loss is is so small that that it is considered considered zero and the engine performance performance date can be gathered without any correction for inlet duct loss being necessary 27. The purpose of slot in the fig. Of impeller (a) (a) Used Used for for bala balanc ncin ing g (b) Ease of fitting fitting in the zig and fixture fixture during during manufactu manufacturing ring (c) (c) Surg Surgee prote protect ctio ion n (d) All All the abov abovee are corr correct ect
28. In fig. The area of the compressor casing the gradually decreasing if it is constant (a) Veloc Velocity ity decrea decreased sed (b) Veloc Velocity ity in even even 29. Match the following (a) EG EGT (b) Acceleration (c) Oil pr. Transducer
(a) D.C. pulse (b) EMF (c) Charge
(d) Fuel flow transducer
(d) Reluctance
30. In the Fig of ignition system R is (a) A co (b) Filter lter (c) Vibra brator tor (d) To producer producer India India interf interferenc erencee 31. In case of post exit thrust reverser (a) Down lock lock pressure pressure is less less than the reflec reflecting ting pressure pressure (b) Down lock lock pressure pressure is more more than the deflect deflecting ing pressure pressure 32. In the APU of the A/C holes are provided near the exhaust the pu is to (a) Exhaust Exhaust duct duct air intake intake cooling cooling oil oil breather breather (b) (b) For For cool coolin ing g (c) (c) Exha Exhaus ustt of of QPU QPU 33. In the secematic of the fuel filter (a) (a) A is is the the inle inlett (b) (b) B is is the the inle inlett (c) (c) C is is the the inle inlett (d) Eithe Eitherr A or or B is is inlet inlet 34. The figure indicates (a) (a) Comp Compre ress ssor or (b) Turbi urbine ne (c) Fan (d) Can not be be indent indentif ified ied 35. In the efficiency graph shown A, B, C, D stand for A B (a) Turbo prop Lowby pass (b) Low by pass turbo prop
C high by pass turbo jet
36. In the filter system if both the filters are clogged the pressure at A will be (a) 10 PSI (b) 60 PSI (c) 30 PSI (d) 20 PSI 37. In given diagram A is (a) (a) Flam Flamee hold holder er (b) Flame Flame stabil stabilize izer r
D turbo jet high by pass
