CF34-Engine survey

CF34-8E Flight Operations Seminar February 2004

GE Aircraft Engines

Flight Operations Support • Established within the GE Customer and Product Support Operation to: – Interface with customer and airplane manufacturer flight operations – Represent their viewpoint within GE – Provide flight operations feedback to GE

• Staffed with pilots with airline, military, flight test, training, and engineering experience • Specific tasks: – – – –

Conduct engine systems/operations briefings and seminars Perform operations surveys Research engine operations questions from customers and aircraft manufacturers Issue and maintain engine operations documents: • Specific operating instructions • Operations engineering bulletins

– Maintain selected airplane flight/operations manuals – Provide pilot support to GE Flight Test Operation – Participate in accident/incident investigations involving GE powered airplanes

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Contact Information:

NOTES

Walt Moeller Technical Pilot GE Aircraft Engines 111 Merchant Street Cincinnati, OH 45246 Phone: (513) 552-6602 [email protected]

3

Outline • • • • • • • •

Program Overview Technical Features Operational Characteristics Testing Normal Operating Considerations Reduced Thrust Erosive FOD and Volcanic Ash Inclement Weather Operation

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NOTES

5

Program Overview

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NOTES

7

Commercial Engines Small

Large CFM56-2

CFM56-3

CFM56-5A

CT7 shaft

CT7 prop CFM56-5B

CFM56-5C

CFM56-7B

T58

T64

CF6-6

CF6-50

CF6-80A

T700/CT7

CF34-1/-3/-8/-10

CF6-80C2

CF6-80E1

GE90 -8EFLIGHTOPS.PPT

GE and CFM engines are built at the following locations:

NOTES

• Lynn, Mass: Small Commercial Turboprop and Turbo Shaft • Durham, NC: Small and Large Commercial Turbo Fans (CF34, CF6, GE90) • Evendale, OH: Large Commercial Turbo Fans (CFM56) • France (Snecma): Large Commercial Turbo Fans (CFM56, CF6)

8

CF34 Engine Family

CF34-3

CF34-8

CF34-10

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NOTES

9

CF34 Family Evolution Military Service

Corporate Service

Regional Jet and Corporate Service

CF34-8C/D/E/C5 CF34-3B/-3B1 CF34-3A1 TF34

CF34-1A/3A

• Long Life Materials

• Reduced Noise

• Serpentine Cooled First Stage Turbine

• Improved Materials • Modularity

USN USAF S-3A A-10

• Boroscope Ports

• New Ignition System

• New Low Emission Combustor

• Hot Day Performance • Higher Flow Compressor • Improved Cruise SFC • Higher Climb/Cruise Thrust

CF34-10

•

50% Thrust Increase 14,500 lbs class

• Thrust Capability to 20,000 Lbs

•

Improved SFC

•

Flat Rated to 86°F

• Growth Capability to 22,000 lbs +

•

FADEC equipped

•

Reduced Parts Count

• Improved Flat Rating

• Improved Maintainability

• Containment • High/Hot Performance

1975

1982 - ’86

1991

1995

1999 - 2003

2004 EIS -8EFLIGHTOPS.PPT

NOTES

10

CF34-8E Technical Features

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NOTES

11

CF34-8E Specifications Engine parameter

-8E2

-8E5

-8E5A1

EMBRAER 170/175

EMBRAER 170/175

EMBRAER 170/175

ISA+15

ISA+15

ISA+15

Normal takeoff thrust (lbs-SLS)*

12,XXX

13,170

13,800

APR thrust (lbs-SLS)*

13,000

14,200

14,200

Length (in.)

128

128

128

Weight (lbs)

2,470

2,470

2,470

Maximum diameter (in.)

52.0

52.0

52.0

Fan diameter (in.)

46.2

46.2

46.2

Fan bypass ratio

5:1

5:1

5:1

Overall pressure ratio

28:1

28:1

28:1

Compressor stages

10

10

10

HPT stages

2

2

2

LPT stages

4

4

4

Aircraft Flat rating temp

(oC)

*Installed, Bleed Off -8EFLIGHTOPS.PPT

NOTES

12

CF34-8E Propulsion System Cross Section Spinner design (“coniptical”) optimized for inclement weather

2 Stage High Pressure Turbine 4 Stage Low Pressure Turbine

10 Stage Compressor

Chevron Exhaust Nozzle Engine control Wide Chord Fan Blades • Full Authority Digital Engine Control (FADEC)

Accessory Gearbox

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•The low pressure system - Single stage fan coupled to 4 stage low pressure turbine

NOTES

•The high pressure system - Variable inlet guide vane assembly - 10 stage HP compressor rotor - 5 variable stator vane assembly - Annular combustor with 18 fuel nozzles - 2 stage HP turbine •The accessory drive system - Power to drive accessories is extracted from HPC front shaft and mechanically transmitted through drive shaft to accessory gearbox

13

CF34-8E Propulsion System

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NOTES

14

CF34-8E Nacelle and Thrust Reverser Thrust reverser Hurel Hispano

Fan cowl Aermacchi Inlet cowl Aermacchi

Aft core cowl Hurel Hispano

EBU systems Aermacchi -8EFLIGHTOPS.PPT

NOTES

15

CF34-8E Powerplant Airflow

Primary Airflow

Secondary Airflow

Parasitic Airflow -8EFLIGHTOPS.PPT

The airflow paths are divided into primary, secondary, and parasitic. Primary is used by the core engine. Secondary is used as fan bypass and parasitic for customer and component requirements.

NOTES

16

CF34-8E Thrust Reverser

Reverse Thrust

Forward Thrust

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Innovative design of nacelle shape and transcowl deployment: •Transcowl naturally blocks bypass duct when deployed •No need for blocker doors •Improved reverse thrust efficiency •Common left hand and right hand nacelle

NOTES

17

CF34-8E Nacelle – Left Side Access FADEC & T2 Access Panel

Operability Bleed Valve Exhaust

Inlet & Piccolo Tube Inspection Panel

Pressure Relief Door

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NOTES

18

CF34-8E Nacelle – Right Side Access Oil Servicing Door

Inlet & Piccolo Tube Inspection Panel

IDG Sight Glass Door

Inlet Anti Ice Exhaust & Piccolo Tube Inspection -8EFLIGHTOPS.PPT

NOTES

19

CF34-8E Engine Bearing Structure

N1 ROTOR #1 BALL BEARING Single Stage Fan Rotor Four Stage Low Pressure Turbine

#2 ROLLER BEARING

#5 ROLLER BEARING

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NOTES

20

CF34-8E Engine Bearing Structure

#4 ROLLER BEARING #3 BALL BEARING

N2 ROTOR Ten Stage High Pressure Compressor Two Stage High Pressure Turbine -8EFLIGHTOPS.PPT

NOTES

21

CF34-8E Engine Sump Structure

A Sump Located in Compressor Front Frame

B Sump Located in Combustion Chamber Frame

C Sump Located in Exhaust Frame -8EFLIGHTOPS.PPT

NOTES

22

CF34-8E Engine Aerodynamic Stations T4.5 INTER TURBINE TEMPERATURE

P3 COMPRESSOR DISCHARGE PRESSURE T2 FAN INLET TEMPERATURE

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NOTES

23

CF34-8E Fan Rotor

BALANCE WEIGHTS FAN BLADE AFT SPINNER RETAINING PIN

FAN DISK

#1 BEARING

#2 BEARING

FORWARD SPINNER -8EFLIGHTOPS.PPT

• The spinner is a hybrid shape of conical (to minimize ice accretion) and elliptical (to reduce ingestion into the core engine of rain and hail)

NOTES

• Wide chord fan blades

24

CF34-8E Fan Stator FAN CONTAINMENT CASE TIE ROD

FAN SPEED SENSOR

OUTLET GUIDE VANE

COMPRESSOR FRONT FRAME

#1 BEARING #2 BEARING

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• The fan case is lined with acoustic panels for noise reduction

NOTES

• The fan case also serves as a blade containment system

25

CF34-8E High Pressure Compressor Rotor STAGE 1 – 2 BLISK

FORWARD SHAFT

STAGE 4 – 10 SPOOL

STAGE 3 BLISK

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NOTES

26

CF34-8E High Pressure Compressor Stator VARIABLE GEOMETRY ACTUATING ARMS

STAGE 4 BLEED MANIFOLD

STAGE 6 BLEED MANIFOLD

INLET GUIDE VANES VARIABLE GEOMETRY VANES

FIXED STATOR VANES

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• The variable inlet guide vanes and four variable stator vane stages serve to match airflow of the forward and aft compressor stages

NOTES

• The variable IGVs and VSVs are controlled by the FADEC • At low N2 speeds they are closed and move toward the open position with increasing N2 speed • Malfunctioning or off schedule VSVs can cause stalls or slow acceleration • Fourth stage compressor air is extracted for sump pressurization • Sixth stage is extracted for air conditioning, nacelle anti-ice, wing anti-ice • Tenth stage is used for air conditioning, nacelle anti-ice and wing anti-ice

27

CF34-8E Combustor OUTER LINER STAGE 1 HIGH PRESSURE TURBINE NOZZLE

NOZZLE SUPPORT SWIRLER INNER LINER

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• Fuel is supplied to the combustor by 18 fuel nozzles equally spaced around its circumference

NOTES

• ignitors are located within the combustor at the 4 o’clock and 8 o’clock positions

28

CF34-8E High Pressure Turbine STAGE TWO NOZZLE

STAGE TWO SHROUD

STAGE ONE SHROUD

STAGE TWO BLADES

STAGE ONE BLADES

STAGE ONE DISK

OUTER TORQUE COUPLING

HPT SHAFT STAGE TWO DISK

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• The HPT nozzle diverts combustor exit gas to the HPT rotor

NOTES

• A serious effect of flight through volcanic ash is that the ash melts in the combustor then solidifies and creates a ceramic coating on the HPT nozzle vanes, Plugging cooling holes and changing the aerodynamics of the HPT nozzle area

29

CF34-8E Low Pressure Turbine STAGE 3 – 6 NOZZLES LOW PRESSURE TURBINE STATOR CASE

LOW PRESSURE TURBINE SHAFT STAGE 3 – 6 ROTORS

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NOTES

30

CF34-8E Accessory Gearbox

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• The AGB is a cast two-piece housing. Drive pads allow for the mounting of the accessories on the forward and aft faces of the gear box. Intermeshed gears are located in the housing. Power is taken form the core rotor of the engine and transmitted to the engine accessories by the gear box

NOTES

• The AGB provides support and drive for all mechanical accessories needed to supply the engine with fuel, lubrication and electrical power. The top of the AGB serves as the oil reservoir.

31

CF34-8E Accessory Gearbox – Aft View Oil Reservoir

Fuel pump

PMA

Starter Air Valve Starter Integrated Drive Generator (IDG)

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NOTES

32

CF34-8E Accessory Gearbox – Forward View Oil Pressure Switch

Chip Detector

Hydraulic Pump

Oil Filter Lube and Scavange Pump

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NOTES

33

CF34-8E Engine Airflow A SUMP PRESSURIZING

PRESSURIZING VALVE

B SUMP PRESSURIZING C SUMP PRESSURIZING

4

6

10

BLEED AIR FOR AIRCRAFT 4TH STAGE SHUTOFF VALVE

HIGH PRESSURE SHUTOFF VALVE

PRESSURE REGULATING SHUTOFF VALVE

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• ECS Bleed Pressures and Temperatures

NOTES

•(Maximum values at ATTCS (APR) thrust) •6th Stage Bleed •Pstatic = 153.6 psia •Temperature = 758 F •10th Stage Bleed •Pstatic = 374.3 psia •Temperature = 1064F

34

CF34-8E FADEC • Full Authority Digital Engine Control – No mechanical connection cockpit to engine – Analogous to “fly by wire” aircraft control system

• Consists of – Dedicated alternator and power supplies – Sensors for control, monitoring and feedback – Cables and connectors

• More than just fuel control functions – – – – –

Start Ignition Variable geometry (VSV’s) Reverse thrust Fault detection

-8EFLIGHTOPS.PPT

FADEC is Full Authority Digital Engine Control. It is the name given to the most recent generation of electronic engine controls currently installed on a variety of high-bypass turbofan engines. FADEC systems are more responsive, more precise, and provide more capability than the older mechanical controls. They also integrate with the aircraft onboard electronic operating and maintenance systems to a much higher degree. The FADEC enhanced engine is not only more powerful and efficient than its mechanically controlled counterpart, it is simpler to operate, and easier to maintain.

NOTES

35

FADEC Control System • Improved operational characteristics – – – – – –

Reduced ITT thermal overshoot Full flight regime thrust management Uniform engine response times Automated starting Built-in thrust ratings Idle speed control for aircraft bleed requirements

• Improved aircraft - engine integration – – – –

Auto-thrust system features and compatibility Less hysteresis Digital aircraft interface Better informed cockpit -8EFLIGHTOPS.PPT

NOTES

36

Ignition System 115V

400Hz

A

Ign A Plugs

B

Ign B

• Features – Two independent systems per engine • Automatically alternated every start

– – – – – –

Either channel can control both ignition boxes Ignition off when N2 >50% Auto relight if “flame-out” sensed Pilot can select continuous ignition Both ignitors on for all air starts If FADEC detects a missed light-off during a ground start attempt the other ignitor will be energized – Ignitors located at the 4 and 8 o’clock position on combustion case -8EFLIGHTOPS.PPT

NOTES

37

VSV Control Feedback Closed

FADEC

A

VSV actuators

FMU

VSV

B

Transient Schedules

Steady state

Open

N2K

• • • • •

Match airflow of Fwd/Aft compressor stages Electrical vs mechanical schedule Steady state schedules maximize efficiency Transient schedule improves stall margin Controlled by FADEC through FMU servo valves

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NOTES

38

CF34-8E Fuel System

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• Fuel supplied by the aircraft fuel tank(s) flows to the centrifugal boost stage of the fuel pump. Upon exiting, the flow divides into two paths. One flow passes through the secondary highpressure gear stage of the pump and then goes back to the aircraft as motive flow.

NOTES

• The second flow exits the pump, passes through the fuel/oil heat exchanger and then flows to the FMU where it enters the fuel filter. • Once filtered, the flow leaves the FMU and returns to the fuel pump where it enters the primary high-pressure gear stage. • The flow leaves the pump and returns to the FMU. The FMU, using commands from the FADEC, meters flow to the fuel injectors through the manifold. The 18 fuel injectors deliver atomized fuel into the combustion chamber, where it mixes with compressor discharge air and is burned. • The fuel pump provides the controlling fuel flow to operate the OBV based on commands from the FADEC 39

CF34-8E Lube System Schematic

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• The lubrication system provides the following functions: oil storage and delivery, pressurization and vent, heat and contamination removal, lubrication/protective barrier against wear and corrosion of internal components.

NOTES

• Oil from the system reservoir, is pressurized by the supply element of the Lube & Scavenge pump, sent to the filter, to the heat exchanger for cooling, and then to the engine bearings. • The scavenge oil is removed from the sumps and the AGB by the scavenge elements of the L&S pump, flows past the chip detector, to the deaerator, and then returns to the reservoir. • Vent air is removed from the sumps and scavenge oil, by the air/oil separator on the AGB, or the deaerator in the oil reservoir, and vented overboard through the drain mast.

40

CF34-8E Operational Characteristics

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NOTES

41

Ratings Transients Operating Limits Exceedances

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NOTES

42

Ratings Versus Thrust Limits • Ratings – Takeoff and MCT – Agency certified

• Thrust limits – – – – – – –

MCL, MCR, for example Not agency certified Specified by aircraft/engine manufacturers Reflected in aircraft power management Basis of aircraft climb, cruise performance Prolong engine life (versus MCT) MCT intended primarily for engine out operation

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NOTES

43

Flat Rate Concept • All GE/CFMI engines • Power managed for – Constant thrust independent of ambient temperature up to “flat rate” temperature – Decreased thrust above flat rate temperature to maintain a constant ITT – Flat rate temperature defined as ISA +∆T (for example ISA + 15oC)

• N1 schedule reflected in – Thrust Rating Computer (TRC), Flight Management System (FMS) – Graphic or tabulated data in operations publications -8EFLIGHTOPS.PPT

NOTES

44

Engine Parameters at Takeoff Thrust I.

Thrust

II.

Constant thrust

N1 Decreasing thrust

TAT

Constant thrust

FRT III.

TAT

Decreasing thrust

FRT

ITT Red Line

ITT Increasing ITT

TAT

Constant ITT

FRT

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I. To meet aircraft performance requirements, the engine is designed to provide a given thrust level to some “Flat Rate” Temperature (FRT). At temperature above FRT, thrust decreases and aircraft performance is adjusted accordingly.

NOTES

II. N1 for takeoff power management schedule increases with OAT (up to FRT) to maintain constant thrust. After FRT, power management N1 (and thrust) decreases. III. ITT increases with OAT to FRT, then remains constant. Any deviation from N1 power management will result in corresponding deviations in ITT. This applies to positive deviations of N1 (overboost) as well as to reduced thrust operation.

45

Altitude Variation SL Thrust Increasing altitude

OAT FRT

Increasing altitude

N1 SL

OAT FRT

ITT

Increasing altitude

SL

OAT FRT -8EFLIGHTOPS.PPT

NOTES

46

Typical FADEC Transient Characteristics

thrust lever angle N2 ITT

N1

thrust lever set

Time -8EFLIGHTOPS.PPT

The power management function on FADEC engines consists of controlling N1 (rather than N2) to produce thrust requested by the thrust lever position. The FADEC uses the ambient conditions (total air temperature, total pressure and ambient pressure) and engine bleed requirements to calculate N1 based on a thrust lever position. Additionally, FADEC modulates the variable stator vanes to maximize engine efficiency during transient and steady state operations. As a result of this increased efficiency, the ITT bloom and droop are reduced.

NOTES

47

Operating Limits • ITT, N1, N2 red lines • Based on the capabilities of hot section and rotating parts • Limits must be compatible with transient characteristics • FADEC engines, with lesser transients, allow higher power management with lower potential for limit exceedances

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NOTES

48

ITT Margin ITT Redline

Margin Deterioration

ITT

TAT

OATL

FRT

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ITT margin is the difference between the ITT redline and the ITT observed on a full thrust takeoff at or above flat rate temperature (FRT). The ITT margin decreases as engine components deteriorate.

NOTES

At temperatures at or above FRT, ITT on a zeromargin engine will reach the ITT redline at takeoff thrust. An engine with a negative ITT margin will reach ITT redline at some temperature less than FRT. This is called the OAT limit (OATL).

49

Contributors to ITT Exceedances • Engine deterioration • Engine hardware damage • Bleed air leak • Inappropriate selection of bleed air based on the thrust configuration

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NOTES

50

Effect of Temperature Inversion at Takeoff I.

Thrust

II.

Constant thrust

N1 Decreasing thrust

TAT

Constant thrust

FRT

TAT

Decreasing thrust

FRT

III.

EGT Increasing EGT

TAT

Constant EGT

FRT -8EFLIGHTOPS.PPT

FADEC will control the engine according to the above charts. Below FRT thrust would be maintained but N1 and ITT would be higher versus no inversion. Above FRT, some loss of thrust would occur (not deemed significant by the aircraft manufacturers) in terms of aircraft performance.

NOTES

51

Testing

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NOTES

53

Overview • A variety of development and certification tests are conducted on GE/CFMI engines. Ground testing is primarily accomplished by GEAE’s Peebles Test Operation in Peebles, Ohio and by comparable SNECMA facilities in France. Flight testing is accomplished by GEAE’s Flight Test Operation in Mojave, California. This presentation summarizes some of these tests and test facilities used.

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NOTES

54

GE Peebles Outdoor Test Facility

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NOTES

55

Crosswind Testing • Objectives – Demonstrate engine operability in crosswinds and tailwinds

• Location – Peebles Test Operation

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A bank of electrically driven fans can rotate 360º around the engine to create headwind, crosswind and tailwind conditions. We look at start characteristics with tailwinds in excess of 50 knots as well as the engine’s resistance to instability during acceleration and high static thrust operation in high crosswind conditions.

NOTES

Shown above is GE90 engine.

56

Cold Weather Testing • Objectives – Demonstrate engine operability in a heavy ice environment for certification and engineering evaluation – Demonstrate a “cold” start

• Location – Peebles Test Operation

-8EFLIGHTOPS.PPT

These tests evaluate impact on hardware and operability of ice build up on non-anti-iced engine components such as fan blades, spinner and booster/HPC stators.

NOTES

Ice is allowed to build up at various power settings, then shed by centrifugal force and temperature rise during engine acceleration. In another test (not shown here), an ice slab is fired into the engine to simulate the shedding of ice that was allowed to build up on the engine because of late or no actuation of inlet anti-ice. Shown above is GE90 engine.

57

Icing Tests in Climatic Hangar (CFM56-3 Upgrade)

-8EFLIGHTOPS.PPT

Normally, icing tests are run at our Peebles, Ohio outdoor test facility. In this case, test stand scheduling and ambient temperature conditions precluded outdoor testing. CFM fabricated a portable version of the Peebles test set-up and shipped it to the USAF climatic hangar in Florida, where the tests were performed with the engine installed on a leased B737-300 in a temperature controlled environment. Outside temperatures were approximately 30 deg C while temperature in the hangar were in the –15 deg C range.

NOTES

58

Bird Ingestion Testing • Objectives – Evaluate impact on engine hardware and operability of bird ingestion

• Location – Peebles Test Operation

-8EFLIGHTOPS.PPT

Large birds (up to 8 lbs.) and medium birds (up to 2 ½ lbs.) are fired into the engine while it is operating at takeoff thrust.

NOTES

Shown above is CFM56-7 engine.

59

Erosive FOD Testing • Objectives – Evaluate ingestion and erosion potential in a FOD environment

• Location – Peebles Test Operation

-8EFLIGHTOPS.PPT

Shown above is CFM56-7 engine.

NOTES

60

Water Ingestion Testing • Objectives – Demonstrate engine operability in a heavy rain environment – Demonstrate starting with water ingestion

• Location – Peebles Test Operation

-8EFLIGHTOPS.PPT

This test simulates a worst case downpour. The engine must demonstrate satisfactory operability.

NOTES

Shown above is CFM56-5C engine.

61

Hail Ingestion Testing

• Objective – Demonstrate engine operability in a heavy hail environment . . . for certification

• Location – Peebles Test Operation

-8EFLIGHTOPS.PPT

One half inch ice cubes are fired through air powered “guns.” The engine must demonstrate satisfactory operability.

NOTES

In another test (not shown here), 1½ inch hailstones are fired into the engine at high thrust to evaluate hardware impact. Shown above is GE90 engine.

62

Fan Blade-Out Testing

Blade Release

Subsequent Stall

-8EFLIGHTOPS.PPT

• Objectives – Demonstrate effect on engine of fan blade released at takeoff thrust • Success Criteria – No fire – No uncontainment – No exceedance of mount loads – Safe shutdown • Location – Peebles Test Operation

NOTES

Shown above is CF34 engine.

63

Mojave Airport

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NOTES

64

A300 Test Bed Aircraft (CF6-80C2 Installed)

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This aircraft, an A300B2 leased from Airbus Industrie, was used as a flying test bed for the CF6-80C2 PMC and FADEC engines.

NOTES

65

A300 Test Bed Aircraft (CF6-50C2 Installed) Water Ingestion Tests

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NOTES

66

B707 Test Bed Aircraft (CFM56-5B Installed)

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This aircraft was used as a flying test bed for CFM56-3/-5A/-5B/-5C engines.

NOTES

67

B707 Test Bed Aircraft (CFM56-3 Installed) Water Ingestion Tests

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NOTES

68

B727 Test Bed Aircraft (UDF Engine Installed)

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NOTES

69

B747 Test Bed Aircraft (GE90 Installed)

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This aircraft, a B747-100, has been used as a flying test bed for all GE and CFM56 engines since 1992, including the GE90, CFM56-7 and CF34 engines. GE believes there is no substitute for in-flight testing. This test bed allows GE to subject our new engines to very rigorous in-flight operability testing before delivery of a new engine to the aircraft manufacturer. This helps account for the outstanding operability reputation of GE and CFM56 engines relative to those of other manufacturers. This test bed was most recently used to flight test the world’s highest thrust engine, the GE90-115B (115,000 pounds of thrust). The GP7000-series (Engine Alliance) engine for the A380 will be tested on the same aircraft as will the CF34-10 regional jet engine.

NOTES

70

B747 Test Bed Aircraft (CFM56-7 Installed)

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NOTES

71

B747 Test Bed Aircraft (CF34-8C Installed)

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NOTES

72

Development and Certification Tests • Operability and Hardware Impact • Crosswind • Ice – Induction icing – Ice slab ingestion – Natural icing (in-flight)

• Medium bird*

– Eight 1-1.5 pound birds (four 2.5 pound birds) – Takeoff power – Maintain thrust lever setting for 5 minutes (demonstrate operability for 20 minutes) – Retain 75% thrust

• Large bird* – – – – – –

Four pound bird (8.0 pound bird) Takeoff power No fire No uncontainment Mount loads not exceeded Normal shutdown

• Water and hail ingestion • Fan blade out • Overlimit *Additional requirements for larger engine effective 9/2000 are shown in parentheses -8EFLIGHTOPS.PPT

NOTES

73

Typical Operability Test Maneuvers Performed • Start – – – –

Ground Air Manual Auto

• Steady state operation – High thrust – Low thrust

• Acceleration – Normal – Burst

• Deceleration – Normal – Chop

• Bodies

-8EFLIGHTOPS.PPT

NOTES

74

Conditions Under Which Maneuvers are Performed • Normal

• Bird ingestion

• Crosswind

• Off schedule VSV’s

• Tailwind

• Off schedule fuel

• Icing

• Suction feed

• Rain

• High angle of attack

• Hail

• Slow speed

-8EFLIGHTOPS.PPT

NOTES

75

Operability Measurements • Time (e.g. to start, accel, decel) • ITT • Thrust response • Stall free • Flameout free • Crew workload requirement

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NOTES

76

Condition

Maneuver

Cross Tail Normal Wind Wind

Ground start Air start Accel (Norm) Accel (Burst) Decel (Norm) Decel (Chop) Bodies Steady State (High) Steady State (Low)

Icing

Rain

Hail

Off Sched Off Bird VSV/ Sched Suct Strike VBV Fuel Feed

Slow High Air Alpha Speed

G

G

G

G

G

-

-

G

G

-

-

-

F

-

-

-

F*

-

-

F

F

F

-

F

G,F G

-

G G,F* G

-

G,F

-

F

-

G

G,F G

-

G G,F* G

-

G,F G,F F

-

F

G,F G

-

- G,F* G

-

G,F

F

-

F

G,F G

-

- G,F* G

-

G,F G,F

-

-

F

G,F G

-

-

-

-

G,F G,F

-

-

-

G,F G

-

G G,F* -

G

-

-

F

F

-

G,F G

G

G G,F* G

-

G,F

-

F

F

F

-

*Not routine test

-

G = Ground F = Flight -8EFLIGHTOPS.PPT

NOTES

77

Normal Operating Considerations

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NOTES

79

Note

• If there are inconsistencies between this presentation and the Aircraft Operations Documents the Aircraft Operations Documents take precedence

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NOTES

80

CF34-8E Preflight

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Inlet Area

NOTES

• Ensure ramp area near inlet is free of FOD, loose snow and ice prior to engine start

81

CF34-8E Preflight

-8EFLIGHTOPS.PPT

Inlet

NOTES

• Remove engine covers and plugs

82

CF34-8E Preflight

-8EFLIGHTOPS.PPT

Inlet/Fan

NOTES

• Check for tools, equipment, snow, ice or FOD on fan blades, spinner or in the lower inlet near the fan • Remove snow or ice with warm air instead of deicing fluid • Check for damaged fan blades • Ensure fan is free to rotate prior to engine start

83

Ice Damage to Fan (CF6)

-8EFLIGHTOPS.PPT

NOTES

84

CF34-8E Preflight

-8EFLIGHTOPS.PPT

T2 Sensor

NOTES

• Check for FOD damage

85

CF34-8E Preflight

3 Fan cowl latches - unlatched

-8EFLIGHTOPS.PPT

Cowls and Thrust Reverser in Open Position

NOTES

• Cowls and thrust reverser are hinged to pylon

86

CF34-8E Preflight

3 Fan cowl latches - unlatched

Fan compartment vent

2 of 3 Fan cowl latches - unlatched -8EFLIGHTOPS.PPT

Fan Cowl

NOTES

• Difficult to see if latches are latched at standing height when close to nacelle • Verify that all three latches are latched. Fan cowl may look secure even though two latches may be unlatched.

87

Loss of Fan Cowl (CF6)

-8EFLIGHTOPS.PPT

We believe this incident was the result of takeoff with one or more cowl latches open.

NOTES

88

Loss of Fan Cowl (CF6) Holes Through Fuselage Above Window Line

-8EFLIGHTOPS.PPT

NOTES

89

CF34-8E Preflight

Core cowl latches (3) - unlatched

Thrust Reverser latches (2) - unlatched -8EFLIGHTOPS.PPT

View of Nacelle – Aft Looking Forward

NOTES

90

CF34-8E Preflight

Pressure Relief Door

Core cowl latches - latched -8EFLIGHTOPS.PPT

Core Cowl – View from 6 o’clock

NOTES

• Open pressure relief door may indicate a pneumatic duct separation

91

CF34-8E Preflight

Drain Mast -8EFLIGHTOPS.PPT

Drain Mast

NOTES

• Maintenance should be requested if large puddles appear under the drain mast

92

Physical Hazard Areas Minimum Idle Thrust WARNING: AIRCRAFT MUST BE POINTED INTO WIND FOR ACCESS TO ENGINE COMPONENTS AT GROUND IDLE Inlet Hazard Area Includes Worst Case 20 Knot Headwind Based on 40 ft/sec Critical Velocity with 3 ft. Contingency Factor

Exhaust Hazard Area Includes Worst Case 20 Knot Headwind with Ground Effects

2.5 M (8.3 ft) Entry Corridor .9 M (2.7 ft) Wide

Engine Exhaust Hazard Area Velocity = 65 MPH or greater = 29.0 m/sec (95.3 ft/sec)

1.7 M (5.7 ft) 1.1 M (3.5 ft) 26 M (86 ft) -8EFLIGHTOPS.PPT

• At min idle thrust, the 65 mph exhaust wake danger area extends aft of the engine approximately 86 feet.

NOTES

93

Physical Hazard Areas Takeoff Thrust

Height Above Ground Plane, Feet

5 4 Meters

Exhaust Velocity Contours Include Worst Case 20 Knot Headwind with Ground Effects

3 2 1 0

16

A B C

14 12 10 8 6 4

D

E

2 0 0

4

8

12

20

24 28 32 36 40 Distance from Core Nozzle Exit, Feet

6

4

2

0

16

8 Meters

10

12

44

48

52

14

56

60 18

16

F 24

6 5 4 3 2 1 0

Distance from Airplane CL, Feeet

7

Meters

Velocity (ft/sec) MAX = 1583 A 50 B 100 C 200 D 400 E 800 F 1500

A B C

20 16

D

E

F

12 8 4 0 0

0

4

8

2

12

16

4

20

24 28 32 36 40 Distance from Core Nozzle Exit, Feet

6

8

10

12

44

48

14

52

16

56

60

18

Meters

-8EFLIGHTOPS.PPT

NOTES

94

Embraer 170 Cockpit

-8EFLIGHTOPS.PPT

NOTES

95

Embraer 170 Cockpit Layout

-8EFLIGHTOPS.PPT

NOTES

96

CF34-8E Engine Control Panel

-8EFLIGHTOPS.PPT

NOTES

97

Embraer 170 Thrust Levers

-8EFLIGHTOPS.PPT

• Flats (detents) at TO/GA and MAX

NOTES

• Thrust reverser deployed by lifting the idle stop lever on the thrust lever and moving thrust lever into the reverse position

98

Embraer 170 EICAS Display

CF34-8E Starter Operating Limits Starting - Ground Operation Start Number

Maximum Time

Followed By

1&2

90 seconds

10 second cool-down

3 through 5*

90 seconds

5 minute cool-down

Starting – In-flight Operation Start Number

Maximum Time

Followed By

1&2

120 seconds

10 second cool-down

3 through 5*

120 seconds

5 minute cool-down

Motoring – Ground or In-flight Operation Motoring Number

Maximum Time

Followed By

1&2

90 seconds

5 minute cool-down

3 through 5*

30 seconds

5 minute cool-down -8EFLIGHTOPS.PPT

Starter Notes

NOTES

• * After 5 sequential start attempts/motorings, cycle may be repeated following a 15 minute cooldown • For ground starts only, the maximum accumulative starter run time per start attempt is 90 seconds (motoring plus start time) • For in-flight starts, the maximum accumulative starter run time per start attempt is 120 seconds (motoring plus start time)

100

CF34-8E Ground Starting Start Sequence 1. Thrust Lever – IDLE position 2. Ignition switch – AUTO 2. Start switch – move to START then release to RUN • FADEC controls starter air valve, ignition and fuel flow - Starter air valve opens when start switch moved to START -

Ignition sequenced on at 7% N2 - Alternate ignitor selected if no light-off in 15 seconds after fuel on - Ignition A (essential bus) – No dispatch message if Ignition A inop. - Ignition B – Short term dispatch if Ignition B inop. - Either FADEC channel can control each ignition exciter - Alternate ignition selected for every other start

-

Automatic Fuel Control - Fuel on at 20% N2 - Light-off typically within 5 seconds after fuel on

-

Starter air valve closes and ignition off at approximately 50% N2 -8EFLIGHTOPS.PPT

Ground Start Notes •

FADEC will prevent engine start if thrust lever is not in the idle position

•

On the ground FADEC will automatically turn off ignition and fuel if a hot start or a hung start is detected • Engine will continue to motor until the pilot manually closes starter air valve by moving STOP/START switch to STOP

•

If no light off within 30 seconds of fuel on the pilot must abort start manually (STOP/START switch to STOP)

•

Dry motor the engine for at least 30 seconds after aborting a start to purge the combustor of residual fuel prior to the next start attempt

NOTES

101

CF34-8E Starting Characteristics Normal Ground Start (All Numerical Values Are “Typical” Not Limits) Idle N2

Idle

light-off (2-4 sec)

N1

Min N1 Display = 8%

30-50 seconds to idle from light-off

Time

light-off occurs before N1 = 8%

Peak ITT = 550-650°C Light-off

ITT

FF

Time

Peak FF = 110-180 pph prior to light-off 500-650 pph after light-off Fuel shutoff open 450-550 pph at idle

460-550°C ITT at idle

Time

Time -8EFLIGHTOPS.PPT

• Light-off - Typically within 2-4 seconds

NOTES

• ITT start limit - 815°C • Oil pressure - Must be indicated by ground idle - May indicate full scale for cold soaked engine • Idle - Indicated by ITT and fuel flow reduction - Typical start time: 40 to 60 seconds - 22% N1, 60% N2, typical idle speeds

102

CF34-8E Ground Start Considerations • START/STOP switch – Switch must be moved from STOP to START in 30 seconds or less or FADEC will prevent engine start – Recycle switch through STOP position for next start attempt

• Starter air pressure – 41 – 48 psi air supply pressure required – Slower starts with lower pressure

• Fan rotation – – –

– –

• Ignition selection is automatic – FADEC alternates A and B ignitors on every other start

• Cold Soaked Engine – Oil temperature must be at least -40 °C prior to engine start – Oil pressure peaks to full scale may occur due to high oil viscosity – Oil pressure should decrease as the oil temperature increases

N1 indication is absolute Tailwind may cause opposite fan rotation Core airflow will gradually override tailwind effect and eventually turn fan in correct direction Minimize tailwind prior to start by repositioning aircraft if practical With strong tailwinds consider manually drymotoring engine (ignition switch OFF) to achieve positive, increasing N1 prior to continuing start (ignition switch AUTO).

• Starts with high residual ITT – –

Expect delayed light-off if starting with residual ITT > 120°C FADEC will automatically dry motor until ITT is less than 120°C, then turn on ignition and fuel

-8EFLIGHTOPS.PPT

NOTES

103

CF34-8E In-Flight Starting Air Start Envelope Windmill

Windmill Only if N2 is greater than 7.2%

Starter Assist

25000

Altitude (ft)

20000 Starter Assist or Windmill if N2 is greater than 7.2%

15000 Starter Assist Required

10000 5000 0 -5000 0

50

100

150

200

250

300

350

Airspeed (kias) -8EFLIGHTOPS.PPT

•

FADEC will not allow engine start if thrust lever is not in the idle position

•

FADEC does NOT provide hot start, hung start or stall protection in the air

NOTES

104

CF34-8E In-Flight Starting Starter Assisted Air Start 1. Thrust Lever – IDLE position 2. Ignition switch – AUTO 3. ITT must be less than 90°C for all air starts • May have to dry motor engine if ITT > 90 °C (Ignition OFF) 4. Start switch – move to START then release to RUN • FADEC controls starter air valve, ignition and fuel flow - Starter air valve opens when start switch moved to START -

Ignition sequenced on at 7% N2 - Both ignitors are on for all air starts

-

Automatic Fuel Control - Fuel on at 20% N2

-

Starter air valve closes and ignition off (auto) at approximately 50% N2

-8EFLIGHTOPS.PPT

Assisted Air Start Notes •

FADEC will prevent engine start if thrust lever is not in the idle position

•

FADEC will NOT provide hot start, hung start or stall protection in the air

•

If N2 has not reached 20% after 15 seconds ignition and fuel will be turned on automatically

•

If no light-off within 30 seconds of initiating start the pilot must abort start manually (STOP/START switch to STOP)

•

Dry motor the engine for at least 30 seconds after aborting a start to purge the combustor of residual fuel prior to the next start attempt

NOTES

105

CF34-8E In-Flight Starting Windmill Air Start 1. Thrust Lever – IDLE position 2. Ignition switch – AUTO 3. ITT must be less than 90°C for all air starts 4. Start switch – move to START then release to RUN • FADEC controls, ignition and fuel flow -

Ignition sequenced on at 7% N2 - Both ignitors are on for all air starts

-

Automatic Fuel Control - Fuel on at 7.2% N2

-

Ignition off (switch in AUTO position) at 50% N2

-8EFLIGHTOPS.PPT

Windmilling Air Start Notes •

FADEC will prevent engine start if thrust lever is not in the idle position

•

FADEC will NOT provide hot start, hung start or stall protection in the air

•

FADEC will not open starter air valve if outside the assisted air start envelope

•

If N2 has not reached 7.2% after 15 seconds ignition and fuel will be turned on automatically

•

Increasing airspeed will increase windmilling engine RPM

•

Start attempt should be discontinued if no light-off within 30 seconds of fuel flow

•

Dry motor the engine for at least 30 seconds after aborting a start to purge the combustor of residual fuel prior to the next start attempt

NOTES

106

CF34-8E Abnormal Starts • Hot Start – The indication of a hot start is an unusually fast ITT increase after ignition. – A start stall condition is indicated by an abnormally slow core speed acceleration and an abnormal increase in ITT as compared to core speed. – The FADEC provides automatic hot start protection (fuel and ignition off) on the ground. The FADEC will not provide automatic hot start protection in the air.

• Hung Start – A hung start is identified by abnormally slow acceleration after ignition and rpm that stabilizes below idle. – During ground starts, the FADEC will automatically turn off fuel and ignition if a hung start is detected. The FADEC will not provide automatic hung start protection in the air.

-8EFLIGHTOPS.PPT

NOTES

107

Taxi • Minimize breakaway thrust – Less than 40% N1 if possible • Reduces FOD potential • Reduces blast hazard

• Operate (warm up) engines two minutes minimum prior to takeoff • Reverse thrust during taxi only in emergency • Oil pressure – Varies with N2 – Minimum 25 psi – May be full scale for cold soaked engine • Should come off full-scale after required minimum 2 minute warm up time prior to takeoff

• Oil temperature – Rise must be noted prior to takeoff – Maximum 155°C continuous, 163°C for 15 minutes

• Oil quantity – “Gulping”

-8EFLIGHTOPS.PPT

NOTES

108

CF34-8E Oil Pressure

-8EFLIGHTOPS.PPT

• Oil pressure varies with N2

NOTES

• Oil pressure less than 25 PSID is permissible for maximum of 10 seconds during “Negative G” operation • Oil pressure below 25 PSID (other than negative-G condition) requires engine shutdown

109

CF34-8E Oil Quantity • Varies inversely with engine speed • Remains constant during steady-state operation • Oil gulping: after engine start, oil level decreases due to distribution within system (sumps, gearboxes and supply scavenge lines) • Increasing oil quantity or lack of gulping could indicate leak in fuel/oil heat exchanger

-8EFLIGHTOPS.PPT

NOTES

110

Taxi (Continued) • Ground operation in icing conditions – Anti-ice on • Anti-ices inlet lip

– During extended operation (more than 30 minutes): • Accelerate engines to 54% N1 and hold for 30 seconds (or to an N1 and dwell time as high as practical, considering airport surface conditions and congestion) – Allows immediate shedding of fan blade and spinner ice – De-ices stationary vanes with combination of shed ice impact, pressure increase and temperature rise • Perform this procedure – Every 30 minutes – Just prior to or in conjunction with the takeoff procedure, with particular attention to engine parameters prior to final advance to takeoff thrust – Any time fan ice accumulation is suspected by perceived or indicated fan vibration -8EFLIGHTOPS.PPT

NOTES

111

Takeoff • Reduced thrust takeoff if conditions permit • Bleeds – On/off depending on company policy/performance requirements – Avoid bleed configuration changes at low altitudes after takeoff

• From an engine standpoint, rolling takeoff is preferred – – – –

Less FOD potential on contaminated runways Inlet vortex likely if takeoff N1 set below 30 KIAS Less potential for engine instability or stall during crosswind/tailwind conditions Observe limitations per aircraft manufacturer’s operations documents

• N1 thrust management – FADEC computes command N1 for max or reduced thrust based on FMS inputs – Thrust lever “stand up” at approximately 40% N1 prior to full thrust (minimizes uneven acceleration) – Pilot sets thrust lever to thrust set (TOGA) position for full thrust or reduced thrust – FADEC maintains N1 at command value -8EFLIGHTOPS.PPT

• FADEC will automatically reduce fan speed to compensate for ITT increase of ECS/anti-ice bleeds based on Takeoff Data Set inputs to the FMS prior to takeoff.

NOTES

• Manual selection of ECS ON below 500 feet above airport altitude at high thrust levels may result in ITT rise above limits unless thrust is momentarily reduced prior to selecting ECS ON. • Manual or automatic selection of cowl or wing anti-ice ON below 1700 feet above airport altitude at high thrust levels may result in ITT rise above limits unless thrust is momentarily reduced prior to selecting cowl or wing anti-ice ON or prior to entering icing conditions with anti-ice in auto mode.

112

ATTCS (Automatic Takeoff Thrust Control System) • Provides additional thrust on takeoff or go-around • Enabled automatically during engine start • Can be turned off for takeoff by pilot input on Takeoff Data Set page on FMS – For takeoff with ATTCS turned off, thrust increase to RSV thrust is NOT available automatically or manually (even with thrust lever push to MAX) – Re-enabled automatically after takeoff phase completed – Always available for go-around

• Windshear (caution or warning) detected – Automatic increase to RSV thrust if ATTCS enabled for takeoff – If ATTCS selected off for takeoff, RSV thrust is still available by manually pushing thrust lever to the MAX position – Automatic increase to RSV thrust is always available for approach/go-around

-8EFLIGHTOPS.PPT

• Thrust lever will stay in TOGA position if thrust increased to RSV level by automatic ATTCS activation

NOTES

• Pilot must manually reduce thrust to maintain ITT within limits

113

CF34-8E5 ITT Operating Limits Thrust (lbf) and ITT Limits Thrust Mode T/O-1

T/O-2 GA

ATTCS

AEO

OEI

ON

T/O-1 13000 (965/949)*

T/O-1 RSV 14200 (1006/990)

OFF

T/O-1 13000 (965/949)

T/O-1 13000 (965/949)

ON

T/O-2 11700 (932/916)

T/O-2 RSV 13000 (965/949)

OFF

T/O-2 11700 (932/916)

T/O-2 11700 (932/916)

ON

GA 13000 (965/949)

GA RSV 14200 (1006/990)

CON 12800 (960)

CON 12800 (960)

CON

-8EFLIGHTOPS.PPT

NOTES * ITT Time limits • 965°C for first 2 min. of the 5 min. • 949°C for remainder of 5 min.

114

Maximum Continuous Thrust

• Intended for use during single engine conditions or emergency situations • NOT intended for normal two engine operations

-8EFLIGHTOPS.PPT

NOTES

115

Climb

• No fixed detent or flat • Based on thrust lever position

-8EFLIGHTOPS.PPT

NOTES

116

Cruise

• Avoid unnecessary use of ignition – Conserves ignitor plug life

• Trend monitoring – Per company policy

-8EFLIGHTOPS.PPT

NOTES

117

Descent • Smooth thrust reduction • Idle most economical • FADEC maintains idle speed to meet bleed demands

-8EFLIGHTOPS.PPT

NOTES

118

CF34-8E Idle Modes • Flight Idle – Activated when in-flight and not in the approach idle mode (see below) – Provides minimum engine bleed pressure sufficient for ECS and anti-ice systems – Fan speed varies as a function of ECS bleed, and anti-ice bleed requirements

• Approach Idle – Activated when the aircraft altitude is less than 15,000 feet, and the flaps are down or the landing gear is down and locked – Used in flight to enable rapid acceleration to go-around thrust

• Final Approach Idle – Activated when: wing anti-ice is selected on, radar altitude is less than 1200 feet above landing altitude – engine idle speed will drop slightly from flight idle to approach idle to allow more descent profile flexibility during the final approach phase of flight – wing anti-ice system performance is maintained by the pilot through thrust lever modulation (cyan line on N1 indication showing minimum N1 to meet wing anti-ice requirements) -8EFLIGHTOPS.PPT

• Idle modes only activated when thrust lever is in the idle detent

NOTES

119

Icing • Cowl anti-ice system protects inlet cowl lip only • Turn on anti-ice prior to entering icing conditions • If ice is inadvertently allowed to accumulate: – Retard one engine at a time to idle before turning A/I on – Turn A/I on, monitor engine while increasing thrust -8EFLIGHTOPS.PPT

NOTES

120

Icing (Continued) • While in icing conditions in flight and – N1 is less than 70% or – If fan/spinner ice build-up is suspected (high indicated or perceived vibration): - Retard thrust lever towards idle, then advance to minimum of 70% N1 for 10-30 seconds or until vibration ceases - Return thrust lever to position required for flight conditions

– Repeat every 15 minutes as required

-8EFLIGHTOPS.PPT

NOTES

121

Landing/Reversing • Fan reversers only • FADEC controls N1 in full reverse – Pilot can move thrust lever(s) to MAX REVERSE detent immediately, but thrust will be limited to idle until reverser(s) deployed

• Modulate reverse if full thrust not needed – Less thermal stress and mechanical loads – Reduced FOD

• Reduce reverse thrust at 80 KIAS • Forward idle by 60 KIAS

-8EFLIGHTOPS.PPT

NOTES

122

Reverse Thrust Effectiveness vs Airspeed 9,000

Knots TAS

Training information only

8,000 7,000 6,000 Net reverse 5,000 thrust (lb/engine) 4,000

150

Reverse thrust 737-300/CFM56-3 SL/STD day Flaps 40

100

50

3,000

0

2,000 1,000 0 20

30

40

50

60

70

80

90

Percent N1 -8EFLIGHTOPS.PPT

NOTES

123

Shutdown • Cool-down prior to shutdown to thermally stabilize engine hot section – Two minute cool-down after coming out of reverse (includes normal taxi thrust lever movements) – One minute cool-down if required - minimize N1 during reverse – Five minute cool-down after high power ground operation such as maximum power assurance check – Cool-down not required for emergency shutdown

• Monitor fuel flow, ITT, N1 and N2 for decrease

-8EFLIGHTOPS.PPT

NOTES

124

Reduced Thrust CF34-8E

-8E FLIGHTOPS.PPT

NOTES

125

Overview • Definitions and restrictions • Benefits • Severity analysis • Performance aspects • Process map and cause/effect chart • Summary

-8EFLIGHTOPS.PPT

NOTES

126

Reduced Thrust Versus Derate • Reduced thrust (Flex thrust) takeoff – Takeoff at less than maximum takeoff thrust using the assumed temperature method or a fixed thrust reduction – V-speeds used protect minimum control speeds for full thrust – Reduced thrust setting is not a limitation for the takeoff, i.e., full thrust may be selected at any time during the takeoff

• Derated takeoff – Takeoff at a thrust level less than maximum takeoff for which separate limitations and performance data exist in the AFM. Corresponds to an “alternate” thrust rating – V-speeds used protect minimum control speeds for the derated thrust . . . not original maximum takeoff thrust – The derated thrust setting becomes an operating limitation for the takeoff

• On some installations derated thrust and reduced thrust can be used together, e.g., a derated thrust can be selected and thrust further reduced using the assumed temperature method -8EFLIGHTOPS.PPT

NOTES

127

AC 25-13 Restrictions • Reduced thrust setting must be at least 75% of the full thrust rating or alternate thrust rating • A periodic takeoff demonstration must be conducted using full takeoff thrust. An approved maintenance procedure or engine condition monitoring program may be used to extend the time interval between takeoff demonstrations • Reduced thrust takeoffs may not be performed – On contaminated runways • “More than 25 percent of the required field length, within the width being used, is covered by standing water or slush more than .125 inch deep or has an accumulation of snow or ice.”

– If anti-skid system is inoperative – These restrictions do not apply to “derated” takeoffs – Any other restrictions on reduced thrust or derated thrust are imposed by the aircraft manufacturer or operator; not by AC 25-13 -8EFLIGHTOPS.PPT

NOTES

128

Typical Additional Restrictions on Reduced Thrust Takeoffs • • • • •

Possible windshear Other MMEL items inoperative Anti-ice used for takeoff Takeoff with tailwind Performance demo “required”

Note: These are typical restrictions that are applied by individual operators. Each additional restriction should be investigated to determine whether or not it is valid. -8EFLIGHTOPS.PPT

When assessing a reduced thrust program, the operator should examine the rationale for each of the additional restrictions that might exist and eliminate restrictions where consistent with flight safety.

NOTES

129

Benefits of Reduced Thrust/Derate • Less severe operation due to lower – Rotational speed – Temperature – Internal pressure

• Less severe operation tends to lower – ITT deterioration rate • Increased time-on-wing

– SFC deterioration rate • Lower fuel burn over the on-wing life of engine

– Maintenance costs • Lower shop visit rate and cost per shop visit

• Reduced thrust on a given takeoff reduces engine stress level and probability of a failure on that takeoff -8EFLIGHTOPS.PPT

NOTES

130

CF34-8E5A1 Engine Parameters (Full Versus Reduced Thrust) At Sea Level, Flat Rate Temperature of 30oC, 0.25 Mach, Typical New Engine Full rated thrust

25% reduced thrust

∆% (or delta)

Thrust (lbs)

11087

8315

-25%

N1 (rpm)

6,878

6262

-9.0%

N2 (rpm)

16,670

16030

-3.8%

ITT (oC)

920

805

-115oC

PS3 (psia)

353

288

-18.4%

-8EFLIGHTOPS.PPT

NOTES

131

Exhaust Gas Temperature (ITT) Deterioration Versus Thrust Rating (Lack of ITT Margin Drives Engines Off Wing and Into the Shop) Cruise ITT Deterioration

Increasing

ITT Deterioration Rate

SL Static Takeoff Thrust Rating

Increasing -8EFLIGHTOPS.PPT

Although we do not have empirical data to allow us to plot ITT deterioration versus derate, we do know that for different thrust ratings of the same engine model the ITT deterioration rate tends to be greater on the higher thrust ratings. This concept is shown in the above chart.

NOTES

132

Specific Fuel Consumption (SFC) Deterioration Versus Thrust Rating (Rate of SFC Deterioration Impacts Fuel Costs) Cruise Fuel Flow Deterioration

Increasing

FF Deterioration Rate

SL Static Takeoff Thrust Rating

Increasing -8EFLIGHTOPS.PPT

Although we do not have empirical data to allow us to plot SFC deterioration versus derate, we do know that for different thrust ratings of the same engine model the SFC deterioration rate tends to be greater on the higher thrust ratings. This concept is shown in the above chart.

NOTES

133

Cycles to Shop Visit Versus Thrust Rating Cycles to Shop Visit

Increasing

Cycles to Shop Visit

SL Static Takeoff Thrust Rating

Increasing

-8EFLIGHTOPS.PPT

Although we do not have empirical data to allow us to plot cycles to shop visit versus derate, we do know that for different thrust ratings of the same engine model the cycles to shop visit tend to be lower on the higher thrust ratings. This concept is shown in the above chart.

NOTES

134

Engine Power Loss Versus Thrust Level • No data on reduced thrust versus engine failures • Following data is for flight phase (takeoff, climb) versus engine failures – Show significantly higher chance of failure at higher thrust settings associated with takeoff

Phase

% Time % Exposure IFSDs

IFSD Factor

% Uncontained Uncontained Failures Factor

% Fire Fires Factor

% Component Separation

% All-engine Power Separation Power Loss Factor Loss Factor

Takeoff

1

4

4

43

43

12

12

23

23

8

8

Climb

14

31

2

30

2

42

3

34

2.5

22

1.6

Takeoff vs Climb Factor

2

21.5

4

9

5

Note: Data for entire high-bypass engine-powered commercial transport fleet Source: “Propulsion Safety Analysis Methodology for Commercial Transport Aircraft,” 1998 -8EFLIGHTOPS.PPT

Example: For an average high bypass turbofan mission (approximately 2 hours) 43% of the uncontained engine failures occur in the 1% of the time spent in the takeoff phase. This yields an “uncontained factor” of 43÷1 = 43 versus the “uncontained factor” for climb which is 30÷14 ~ 2. Thus, an uncontained failure is 21.5 times more likely to occur in the takeoff (higher thrust) phase than the climb (lower thrust) phase of flight. To make the point that an engine failure is less likely at reduced thrust, one can think of the takeoff phase as a “full thrust” takeoff and the climb phase as “reduced thrust.” Thus, the data would show a significantly higher chance of engine failure at full thrust than reduced thrust.

NOTES

135

Severity Analysis

• A means of quantifying and predicting mission severity based on how the engine is used • Analysis and limited field data has shown that mission severity is a function of average flight length and the amount of reduced thrust used and is expressed as a “severity factor”

-8EFLIGHTOPS.PPT

NOTES

136

Severity Analysis (Continued) • Application – Establish baseline severity factor using • Actual flight length • Current effective derate* –The sum of 3 “partial derates” representing takeoff, climb, and cruise

– When these values are varied, a new severity factor results – Impact on severity is estimated by ratioing the new severity factor to the baseline severity factor * For the purpose of this discussion “derate” is used interchangeably with “reduced thrust” -8EFLIGHTOPS.PPT

NOTES

137

Severity Analysis (Continued) 1-Hour Flight Length 16

Partial Derate (%)

2-Hour Flight Length

Takeoff

Takeoff

16

12

3-Hour Flight Length

8

8

4

Cruise

4

0

10

20

30

Operational Derate (%)

Takeoff

12

12

Climb

16

Climb Cruise 0

10

20

30

Climb Cruise

8 4

0

Operational Derate (%)

10

20

30

Operational Derate (%)

(Effective Derate = Partial Takeoff % + Partial Climb % + Partial Cruise %) 1.6

Severity 1.2 Factor 0.8

0 10 % Effective Derate 20

0.4 0

2.0

4.0

Flight Length - Hours -8EFLIGHTOPS.PPT

• Severity of operation is a function of flight length and “effective derate” which is a composite of takeoff, climb and cruise reduced thrust/derate. The contributions of each phase are additive and the sum of the contributions represents “effective derate.” The charts above demonstrate this concept as well as the fact that the order of importance, in terms of effective derate contribution, is takeoff, climb and cruise.

NOTES

• T/O is weighted heavier on shorter flights; climb and cruise derate are weighted heavier (relative to takeoff) on long flights. Further, a given amount of effective derate has more impact on shorter flights. • The above charts are intended only to help illustrate the concept that effective derate is a composite of takeoff, climb and cruise derate, depending on flight length and the impact of flight length on severity factor. This visualization is not used in the pricing of maintenance service contracts.

138

Severity Analysis (Continued)

CFM56 Severity Factor Table

Flight Length (Hours)

Effective Derate

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

0.25 0.30 0.35 0.50 0.75 1.00 1.25 1.40 1.50 1.75 2.00 2.20 2.50 3.00 3.25 3.50 3.75 3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00 8.00 9.00 10.00 12.00

4.686 4.016 3.537 2.676 2.005 1.670 1.469 1.383 1.335 1.239 1.168 1.122 1.067 1.000 0.974 0.952 0.933 0.952 0.916 0.888 0.866 0.848 0.832 0.820 0.809 0.791 0.777 0.765 0.749

3.653 3.153 2.795 2.151 1.651 1.400 1.250 1.186 1.150 1.079 1.025 0.991 0.950 0.900 0.880 0.864 0.850 0.864 0.837 0.816 0.800 0.786 0.775 0.765 0.757 0.743 0.733 0.724 0.712

2.966 2.575 2.297 1.795 1.405 1.210 1.093 1.043 1.015 0.959 0.918 0.891 0.859 0.820 0.805 0.792 0.781 0.792 0.771 0.755 0.742 0.731 0.722 0.715 0.709 0.698 0.690 0.683 0.674

2.502 2.185 1.959 1.553 1.236 1.078 0.983 0.943 0.920 0.875 0.841 0.819 0.793 0.762 0.750 0.739 0.730 0.739 0.722 0.709 0.698 0.690 0.683 0.677 0.671 0.663 0.656 0.651 0.643

2.185 1.919 1.729 1.387 1.121 0.988 0.909 0.874 0.855 0.817 0.789 0.771 0.749 0.722 0.712 0.703 0.696 0.703 0.689 0.678 0.669 0.662 0.656 0.651 0.646 0.639 0.634 0.629 0.623

1.966 1.735 1.570 1.274 1.044 0.928 0.859 0.829 0.813 0.780 0.755 0.740 0.721 0.698 0.689 0.681 0.675 0.681 0.669 0.659 0.652 0.645 0.640 0.636 0.632 0.626 0.621 0.617 0.611 -8EFLIGHTOPS.PPT

This chart is used for illustrating the concept of severity factor. It is not intended for use in pricing maintenance contracts.

NOTES

139

Severity Analysis (Continued)

CFM56 Partial Derates Flight Time Hours 0.25 0.50 0.75 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.50 7.00 7.50 8.00 8.50 9.00 9.50 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00

P T/O

P CL

P CR

0.8667 0.7817 0.7100 0.6400 0.5717 0.5200 0.4807 0.4500 0.4233 0.4033 0.3883 0.3767 0.3693 0.3630 0.3580 0.3533 0.3490 0.3450 0.3413 0.3380 0.3350 0.3323 0.3300 0.3280 0.3263 0.3250 0.3240 0.3233 0.3227 0.3220 0.3213 0.3207

0.0900 0.1410 0.1790 0.2100 0.2400 0.2600 0.2723 0.2800 0.2843 0.2877 0.2907 0.2930 0.2950 0.2967 0.2980 0.2993 0.3003 0.3010 0.3017 0.3023 0.3027 0.3030 0.3033 0.3037 0.3040 0.3043 0.3047 0.3050 0.3053 0.3057 0.3060 0.3063

0.0433 0.0773 0.1110 0.1500 0.1883 0.2200 0.2470 0.2700 0.2923 0.3090 0.3210 0.3303 0.3357 0.3403 0.3440 0.3473 0.3507 0.3540 0.3570 0.3597 0.3623 0.3647 0.3667 0.3683 0.3697 0.3707 0.3713 0.3717 0.3720 0.3723 0.3727 0.3730 -8EFLIGHTOPS.PPT

NOTES

140

Severity Analysis (Continued) • Example No. 1 (CFM56) . . . varying takeoff derate (increase from 10% to 15%) – Baseline • • • • • •

2.0-hour flight leg Takeoff derate 10%, partial derate Climb derate 10%, partial derate Cruise derate 15%, partial derate Effective derate Severity factor: 0.901

5.2% 2.6% 3.3% 11.1%

– Variant • • • • • •

2.0-hour flight leg Takeoff derate 15% , partial derate Climb derate 10%, partial derate Cruise derate 15%, partial derate Effective derate Severity factor: 0.861

7.8% 2.6% 3.3% 13.7%

– Severity ratio (variant/baseline) = 0.861 ÷ 0.901 = 0.956 • Approximately 4.4% reduction in severity -8EFLIGHTOPS.PPT

NOTES

141

Severity Analysis (Continued) • Example No. 2 (CFM56) . . . varying climb derate (increase from 0% to 5%) – Baseline • • • • • •

2.0-hour flight leg Takeoff derate 10%, partial derate Climb derate 0%, partial derate Cruise derate 15%, partial derate Effective derate Severity factor: 0.950

5.2% 0.0% 3.3% 8.5%

– Variant • • • • • •

2.0-hour flight leg Takeoff derate 10%, partial derate Climb derate 5% , partial derate Cruise derate 15%, partial derate Effective derate Severity factor: 0.922

5.2% 1.3% 3.3% 9.8%

– Severity ratio (variant/baseline) = 0.922 ÷ 0.950 = 0.971 • Approximately 2.9% reduction in severity -8EFLIGHTOPS.PPT

NOTES

142

Severity Analysis (Continued) 2-Hour Flight Leg Climb Derate = 10% Cruise Derate = 10%

Estimated Severity Reduction Due to the Use of Reduced Takeoff Thrust

Estimated Severity Reduction %

0

5

10

15

20

25

Average Takeoff Reduced Thrust - %

-8EFLIGHTOPS.PPT

This chart represents the relative impact of reduced thrust increments on severity. Note that the slope of the curve is greater in the 0 to 5% increment than in the 20 to 25% increment, but that the slope is still substantially positive even at the higher increments of reduced thrust. This shows that the first increment of thrust reduction is the most important but that thrust reduction even at the higher increments is important.

NOTES

143

Severity Analysis (Continued) 2-Hour Flight Leg Takeoff Derate = 10% Cruise Derate = 10%

Estimated Severity Reduction Due to the Use of Reduced Climb Thrust

Estimated Severity Reduction %

Takeoff

Climb

0

5

10

15

20

25

Average Climb Derate Thrust - %

-8EFLIGHTOPS.PPT

This chart shows that the impact of climb thust reduction on severity, while still positive, is not as great as for takeoff thrust reduction.

NOTES

Although climb thrust reduction may reduce engine severity, its use may actually increase fuel burn on a given flight because of the lesser time spent in the highly fuel efficient cruise phase of flight.

144

Performance Aspects • Logic for calculating reduced takeoff N1 with the assumed temperature method: Note: this logic is incorporated in your FCOM/Operations Manual procedures – not a manual crew calculation – 1. Find allowable assumed temperature using takeoff analysis chart – 2. Find gage N1 (maximum) corresponding to assumed temperature – 3. Convert the gage N1 (maximum) for the assumed temperature to a value of corrected N1 using the assumed temperature • This represents the thrust required if actual temperature was equal to assumed temperature value

– 4. Convert this corrected N1 back to the gage N1 using the actual temperature • This gage N1 value will yield a corrected N1 (and thrust) equivalent to that achieved in Step 3

-8EFLIGHTOPS.PPT

NOTES

145

Performance Aspects (Continued) 1.

Obtain max assumed temp (TF) from airport analysis

N1 with no thrust reduction

4.

2. Find max N1

N1K at TF decorrected to N1 at ambient TA

for TF

∆N1

3. N1 max at TF corrected

N1K

to N1K at TF

∆N1K N1 TISA

TA

TFRT

TF

OAT

N1 = Physical (gage) N1 N1K = N1 corrected for temperature -8EFLIGHTOPS.PPT

This is a graphic representation of the logic on previous chart

NOTES

146

Performance Aspects (Continued) • Calculating reduced thrust N1 using the assumed temperature method – Example 1 737-400, CFM56-3B-2 (22k rating) engines. Temperature is 20oC, wind is calm, takeoff weight will be 52,300 kg • From the takeoff analysis the assumed temperature will be 55oC • From the takeoff N1 chart the gage N1 at 55o is 93.8% • The corresponding corrected N1 is 87.9% 93.8 ÷

(55 + 273.16) = 87.9 288.16

• The gage N1 for 87.9% corrected N1 at 20oC is 88.7% 87.9 X

(20 + 273.16) = 88.7 288.16

-8EFLIGHTOPS.PPT

NOTES

147

Performance Aspects (Continued) • For a given takeoff, there is obviously more performance margin at full thrust than at reduced thrust; however, – Reduced thrust takeoffs meet or exceed all the performance requirements of the FAA and other regulatory agencies – For a reduced thrust takeoff at a given assumed temperature, the performance margin is greater than for a full thrust takeoff at an ambient temperature equal to the assumed temperature

-8EFLIGHTOPS.PPT

NOTES

148

Performance Aspects (Continued) • For reduced thrust case, V-speeds are based on assumed temperature while aircraft is operating under ambient temperature conditions – Thus, TAS at a given V-speed is less • Significant improvement in field length performance • No significant impact on climb-out performance

-8EFLIGHTOPS.PPT

NOTES

149

Performance Aspects (Continued) • For Example: a B737-300 (CFM56-3B2) at sea level, 16°C. The actual take-off weight permits an assumed temperature of 40°C Temperature (oC):

40

16 assuming 40

%N1

95

91.5

V1 (KIAS/TAS)

137/143

137/137

VR (KIAS/TAS)

139/145

139/139

V2 (KIAS/TAS)

146/153

146/146

Thrust at V1 (lb per engine)

16,036

16,210

F.A.R. field length - ft

6,500

6,022

Accelerate-stop distance (engine out) (ft)

6,500

6,006

Accelerate-go distance (engine out) (ft)

6,500

6,022

Accelerate-go distance (all engine) (ft)

5,400

4,990

Second segment gradient

3.07%

3.19%

475

474

Second segment rate of climb – ft per minute

-8EFLIGHTOPS.PPT

NOTES

150

Tools to Analyze Reduced Thrust Programs Process Map (Typical) Does one or more of the following conditions exist:

Preflight planning

• • • •

Calculate allowable reduced thrust using:

Perfom demo required Brake deactivated Anti-skid inop Other MMEL items

No

•Load sheet •Runway data •Winds •Outside air temperature

Full Thrust Takeoff Performed

Yes

• • • • • •

No

Yes

Yes

Does one or more of the following conditions exist:

Is reduced thrust precluded by performance requirements?

Contaminated runway Noise abatement required De-icing performed Wind shear forecast Anti-ice for T/O Tailwind for T/O

No

Deviation due to pilot discretion?

No

Yes

Pilot’s choice

Takeoff performed at reduced thrust but not max allowable

Takeoff performed at max allowable reduced thrust

At time of takeoff -8EFLIGHTOPS.PPT

This is a process map for a typical operator with the typical company restrictions on reduced thrust discussed earlier in this presentation. Note that there are many hard decision rules and discretionary decisions on the part of the pilot that may result in full thrust takeoffs or takeoffs at less than maximum allowable reduced thrust.

NOTES

151

Periodic Takeoff Demonstrations • Operator methods vary e.g. – Every tenth takeoff – Every Friday – Never make dedicated full thrust T/O for performance verification • Take credit for ECM and full thrust T/O’s performed for operational reasons

• Less reduced thrust benefits acrue when unnecessary full thrust takeoffs are performed • Full thrust takeoffs meaningful only when takeoff is performed at the flat rate temperature; otherwise the takeoff data must be extrapolated to flat rate temperature – Reduced thrust takeoffs can be extrapolated as well – Cruise ECM data can also be used to predict ITT margin

• Negotiate with regulatory agency to extend interval between dedicated performance verification takeoffs – Take credit for ECM programs (T/O or Cruise) – Take credit for full thrust takeoffs performed for operational requirements – Extrapolate data obtained during reduced thrust as well as full thrust takeoffs -8EFLIGHTOPS.PPT

NOTES

152

Summary • Reduced thrust benefits – – – – –

Longer on-wing time between engine refurbishment Fewer operational events due to high ITT Lower fuel burn over on-wing life of engine Lower probability of engine failure on a given takeoff Lower maintenance costs

• Severity analysis helps estimate reduced thrust impact on engine severity factor – Reduced thrust has significant impact on severity – Takeoff thrust reduction has greater impact than climb thrust reduction – 1st increment of thrust reduction has greatest impact -8EFLIGHTOPS.PPT

NOTES

153

Summary (Continued) • Reduced thrust takeoffs meet or exceed FAR or other regulatory requirements – Significant margin due to operation at actual ambient temperature while V-speeds are based on assumed temperature

• May be useful to look at steps in reduced thrust process where use of reduced thrust might be compromised

-8EFLIGHTOPS.PPT

NOTES

154

Erosive FOD and Volcanic Ash

-8E FLIGHTOPS.PPT

NOTES

155

Erosive FOD

• What is it? – Dust – Sand – Volcanic ash – Debris from deteriorated runways/ramps/taxiways

-8EFLIGHTOPS.PPT

NOTES

156

Effect on Engines • Erodes airfoils resulting in: – Reduced parts life – Reduced ITT margin – Increased fuel consumption – Reduced airfoil strength (extreme case) – Reduced stall margin (extreme case)

• Blocks cooling flow passages – Higher temperatures for hot section parts

• May be incurred in single occurrence or cumulatively from frequent exposures

-8EFLIGHTOPS.PPT

NOTES

157

Sources • Contaminated runways, taxiways, ramps • Airborne particles (dust, sand, volcanic ash) • High FOD potential areas: – Desert and coastal airports – Airports with: • Construction activity • Deteriorated runways/ramps/taxiways • Narrow runways/taxiways • Ramps/taxiways sanded for winter operations • Plowed snow/sand beside runways/taxiways

-8EFLIGHTOPS.PPT

NOTES

158

Engine Vortices • Common cause of ingestion on ground • Strength increases at high thrust, low airspeed • Somewhat destroyed by: – Airspeed – Headwind – General rules: • 10 knots airspeed/headwind will destroy vortices formed up to 40% N1 • 30 knots airspeed will destroy vortices formed at typical takeoff thrust settings

-8EFLIGHTOPS.PPT

NOTES

159

Engine Vortex (CF6 Engine)

-8EFLIGHTOPS.PPT

NOTES

160

Airspeed Effect on Vortex Formation (Data from scale model and actual engine ground tests) 111 102

N1, %

Vortex

70

No vortex

50 40 30

Legend 1/16 model, test 1 455-115/4 in Cell 2 1/6 model, test 2

20

0

10

20

30

40

Air speed relative to inlet, knots -8EFLIGHTOPS.PPT

NOTES

161

High Exposure Operations • Thrust advance for breakaway from stop • 180 degree turn on runway or taxiway – Overhang of unprepared surface – Thrust assist in turn from outboard engine

• Thrust advance for takeoff • Reverse thrust at low airspeed • Power assurance runs

-8EFLIGHTOPS.PPT

NOTES

162

Recommendations/Considerations • Avoid engine overhang of unprepared surface – If unavoidable, leave engines at idle

• Minimize breakaway thrust – Less than 40% N1, if possible

• Minimize taxi thrust – Avoid allowing aircraft to come to complete stop

• Reverse during taxi only for emergency stopping • Avoid taxiing closely behind other aircraft where FOD may be blown -8EFLIGHTOPS.PPT

NOTES

163

Recommendations/Considerations (Continued) • Minimize thrust for crossbleed starts – Just high enough for adequate manifold pressure – Consider location for minimum FOD prior to crossbleed start

• Minimize thrust assist from outboard engine in 180 degree turn, particularly if outboard engine overhangs unprepared surface • Rolling takeoffs, if possible (follow aircraft manufacturer procedures) – 30 kias destroys vortices formed at typical takeoff thrust settings -8EFLIGHTOPS.PPT

NOTES

164

Recommendations/Considerations (Continued) • Reverse thrust – Minimize reverse thrust use on contaminated runways – Reverse thrust is more effective at high speed • Use high reverse thrust early, if necessary

– Start reducing reverse thrust per aircraft operations manual • For FOD conditions, at 80 kias, if practical • Most installations are certified for full thrust use to 60 kias (without engine instability) but re-ingestion of exhaust gases/debris may occur at full reverse thrust below 80 kias

– Select forward thrust at taxi speed and before clearing runway

-8EFLIGHTOPS.PPT

NOTES

165

Effect of N1 and Airspeed on Net Reverse Thrust Knots TAS 8,000

Net 6,000 reverse thrust (lb per 4,000 engine)

“Training information only” Reverse thrust 737-300/CFM56-3 SL/Std day Flaps 40

150 100 50 0

2,000 0 20

30

40

50

60

70

80

90

Knots TAS 16,000

Net 12,000 reverse thrust 8,000 (lb per engine)

200

“Training information only” Reverse thrust 747-400/CF6-80C2 SL/Std day Flaps 30

150 100 60 30 0

4,000 0 30

40

50

60

70

80

90

100

Percent N1

Percent N1

-8EFLIGHTOPS.PPT

NOTES

166

Volcanic Ash • Problem – – – – –

Ash builds up on HPT nozzles and blades Nozzle area reduced, cooling holes blocked Engine surges/stalls, high ITT Severe engine damage, power loss Encountered at all altitudes

• Recognition – – – – –

Smoke/dust in cockpit Odor similar to electrical smoke St. Elmo’s fire/static discharges Orange glow in engine inlets Multiple engine malfunctions/flameouts

Note: Ash may be difficult to detect at night and weather radar is not an effective means of detection -8EFLIGHTOPS.PPT

In 1982, two 747 aircraft experienced multiple engine flameouts/shutdowns as a result of flying through volcanic dust at 37,000 ft and 30,000 ft. In one of these incidents, all four engines lost thrust within 50 seconds. In 1989, a 747/400 entered a cloud of volcanic ash at 25,000 ft resulting in immediate flameout of all four engines. In all cases, serious engine damage occurred, aircraft surfaces were eroded, windshield visibility was restricted and airspeed readings were unreliable due to blocked pilot systems. Successful airstarts were accomplished by 12,500 ft.

NOTES

The volcanic dust affected the engine by causing rapid erosion of the compressor and build up of fused volcanic ash on the HPT nozzles and blades. The result is increased ITT, engines surges/stalls, torching from the tailpipe, power loss and flameout. It has been shown that the weather radar cannot be relied on to detect volcanic ash. Also, the ash is difficult to detect at night or in clouds but other indications may be present such as St. Elmo’s fire and an orange glow in the engine inlet.

167

CF6-80C2B1F Encounter • December 1989, B747-400 descended in Mt. Redoubt ash cloud • Ash cloud had visual characteristics of normal overcast • Cloud entry at 26,000 feet • Dust/smoke in cockpit immediately after cloud entry • Maximum climb thrust selected to climb out of ash

-8EFLIGHTOPS.PPT

NOTES

168

CF6-80C2B1F Encounter (Continued) • After approximately one minute at high power, all four engines lost thrust (spooled down to below idle) • After five or six start attempts, engine No. 1 and No. 2 restarted at 17,200 feet, engine No. 3 and No. 4 restarted at 13,300 feet • Subsequent operation normal, but higher ITT levels

-8EFLIGHTOPS.PPT

NOTES

169

Fan and Spinner • Spinner erosion was evident • Fan blades were dusted with ash • Fan blade outer panel leading edges were slightly roughened • Light polishing was required to restore original finish

-8EFLIGHTOPS.PPT

NOTES

170

-8EFLIGHTOPS.PPT

NOTES

171

High Pressure Compressor Blades, Stage 10

• Leading edge erosion near the blade tip – Resulted in concave leading edge profile

• Blades were razor sharp on the corners and tips

-8EFLIGHTOPS.PPT

NOTES

172

-8EFLIGHTOPS.PPT

NOTES

173

Stage 1 High Pressure Nozzle Guide Vanes • Surface deposits were recrystallized ash • High temperature operation formed harder ceramic layer – Total ash thickness was approximately 0.3 inch

• Ash buildup caused reduction in nozzle flow area – Increased compressor operating line – Reduced stall margin – Lowered HPT efficiency

-8EFLIGHTOPS.PPT

NOTES

174

-8EFLIGHTOPS.PPT

NOTES

175

Stage 1 HPT Blade • All blades were eroded down to the tip cavity • Cooling holes appeared to be open • No indication of overtemperature • Most blades not reusable due to excessive tip wear

-8EFLIGHTOPS.PPT

NOTES

176

-8EFLIGHTOPS.PPT

NOTES

177

Volcanic Ash • Recommendations – – – – – – –

AVOID FLIGHT NEAR VOLCANIC ACTIVITY Fly on upwind side of dust If in dust, exit immediately Turn on continuous ignition Turn off auto-throttle Reduce thrust to idle or low as practical Turn on all available airbleed systems • Wing and nacelle anti-ice • A/C packs on high

– If engine is shutdown/flameout, restart using published procedures – Resume normal operations upon exiting dust

-8EFLIGHTOPS.PPT

Since severe consequences can result by flying through volcanic ash, the best policy is to avoid ash clouds. However, if volcanic ash is encountered, immediate action should be taken to leave the cloud by the shortest distance/time. Other procedures can be accomplished to reduce engine damage and possible loss of power. Turning off the auto-throttle prevents thrust levers from increasing thrust to recapture airspeed that is indicating low due to pitot system blockage with ash. By reducing power when encountering ash, the lower ITT will reduce the debris build up in the HPT. Turning on all bleed systems increases the stall margin. If the engine is shutdown due to overtemperature/stalls or flameouts, attempt restart(s) using flight manual procedures. Successful starts may not be possible until clear of the ash cloud and within the airstart envelope. At high altitude engines are slow to accelerate to idle which may be interpreted as a failure to start.

NOTES

178

Compressor Stall Margin P3/P2.5 Stall line Stall Margin (volcanic ash) Stall Margin (Normal)

Operating Line (Volcanic Ash) Operating Line (Normal)

Compressor Air Flow

P3 = compressor discharge pressure P2.5 = compressor inlet pressure Volcanic ash build up on HPT nozzle raises operating line Bleeding engine lowers operating line

-8EFLIGHTOPS.PPT

The engine high pressure compressor operates at a given pressure ratio (compressor inlet pressure/compressor discharge pressure) to push a given amount of air through the compressor. The locus of points of pressure ratio versus compressor airflow (airflow is higher at higher power settings) represents the “compressor operating line.” There is also a locus of points (above the operating line) of pressure ratio versus compressor airflow at which the compressor will stall; that is, the flow will be disrupted through the compressor.

NOTES

When the engine encounters volcanic ash, the ash melts in the combustor of the engine and then deposits itself as a ceramic material on the stators (nozzles) leading into the high pressure turbine. This build up of ceramic material causes a higher pressure ratio to drive the same amount of air through the engine; thus, the operating line of the engine goes up toward the stall line, reducing what we call “stall margin.” By turning bleed on, we lower the pressure ratio required for a given airflow, lowering the operating line and restoring some of the stall margin that is lost because of the volcanic ash encounter. 179

Inclement Weather Operation

-8EFLIGHTOPS.PPT

NOTES

181

Inclement Weather Operation

• Rain and Hail • Icing Conditions

-8EFLIGHTOPS.PPT

NOTES

182

Rain and Hail • FAR 33 Requirements – Water ingestion 4% by weight of engine airflow-idle to takeoff thrust • Confirm operability (acceleration and stall/flameout resistance) in heavy rain

– Hail Testing • Confirm mechanical integrity after FOD – Volleys of large hailstones fired at takeoff thrust

• Confirm operability in heavy hailstorm conditions (smaller hailstones but heavier concentration)

-8EFLIGHTOPS.PPT

NOTES

183

Rain and Hail (Continued) • Weather threat – Worst case precipitation occurs in convective storms – Threat (Liquid Water Content - LWC, or Hail Water Content - HWC) • Rain: 20 g/m3 (LWC) at 20,000 feet • Hail: 10 g/m3 (HWC) at 15,000 feet

-8EFLIGHTOPS.PPT

Hail is a more severe engine operating environment than is rain; thus, the hail threat occurs at a lower water content than rain.

NOTES

184

Rain and Hail (Continued) • Effect on engine operation – Reduces engine tolerance to: • Engine rollback • Surge/stall • Flameout

• Effect varies with: – Engine speed – Aircraft speed – Engine configuration/geometry – Type of precipitation

-8EFLIGHTOPS.PPT

NOTES

185

Rain and Hail (Continued) Migration of Operating Line Accel schedule Rollback

Fuel flow (WF) Burner pressure (PS3) Operating line in water Operating line dry

Decel schedule

Core speed (N2) -8EFLIGHTOPS.PPT

In rain and hail conditions, the engine requires a higher WF/PS3 ratio to maintain a given N2. The WF/PS3 ratio to run at a given N2 eventually is constrained by the maximum accel schedule. At this point N2 will roll back on the accel schedule, which may lead to a flameout.

NOTES

186

Rain and Hail (Continued) Scoop Factor Effect • Inlet air spillage at low engine RPM/high aircraft speed increases engine face water/air ratio

• High engine RPM/low aircraft speed decreases engine face water/air ratio by reducing air spillage

-8EFLIGHTOPS.PPT

An air/water column enters the engine at the inlet. At higher aircraft speeds and lower engine speeds, some of the air “spills” over at the inlet. This same spillage of water does not occur. Thus, the water/air ratio increases, creating a more severe operating environment for the engine. At lower aircraft speeds this air spillage is not as great.

NOTES

Practically speaking, the crew cannot vary airspeed much due to the requirement to maintain turbulence penetration airspeed in a thunderstorm. In general, it is more practical to increase engine speed.

187

Rain and Hail (Continued) Configuration effects • Coniptical spinner - used on new GE/CFMI engines Coniptical

Conical

Elliptical

Note: This spinner design is on the GE90, CFM56-7 and CF34-8E

-8EFLIGHTOPS.PPT

The “coniptical” spinner is a compromise between the conical and elliptical and is used on the newer engine models.

NOTES

188

Rain and Hail (Continued) • GE/CFM analysis and testing – Driven by CFM56-3 flameouts in late 1980’s – Extensive analysis – Ground test • Water and hail (necessitated developing new test rig) • CFM56-3 (various configurations) • CF6-50 (as baseline…this engine was the standard)

– Flight test • Water only…USAF KC135 tanker with water flow capability • B707 test bed with CFM56-3 engine installed • A300B with CF6-50 engines installed

– Correlated flight tests with ground tests

-8EFLIGHTOPS.PPT

NOTES

189

Rain and Hail (Continued) • Operational recommendations – Avoidance – If encountered: • • • • • •

Ignition-on Engine anti ice-as required by FCOM/OM Auto-thrust-off Increase engine speed, if practical Avoid rapid thrust lever movements APU-start (if available)

– If power loss is experienced • Use appropriate published aircraft manual procedures – Note: Restart may not be possible until exiting rain/hail conditions

-8EFLIGHTOPS.PPT

These are generic recommendations made by an industry committee formed to address the issue of power loss in rain and hail conditions. These recommendations have been incorporated to various degrees by the aircraft manufacturers, depending on applicability and manufacturer philosophy.

NOTES

For example, Boeing has the discussion on the following chart for the B737 classic, which is nonFADEC and does not have auto-relight capability. For commonality with the NG airplane they have the same procedure even though the CFM56-7 installation has the auto-relight feature. Airbus, with all CFM56 FADEC (auto-relight) engines on their airplanes does not have a procedure. In any case, avoidance of thunderstorms and hail by overflight or circumnavigation is always a prudent course. Although extremely unlikely, there is always a possibility that the airplane could encounter conditions more sever than those to which the engine/airplane is certified.

190

Icing Areas of Engine Icing HPC first Stages

Inlet Spinner

Fan blades

Fan OGV’s

-8EFLIGHTOPS.PPT

NOTES

191

Icing Areas of Engine Icing (Continued) • Spinner shape – Conical: Provides best ice accretion characteristics (minimizes) – Elliptical: Provides best hail ingestion capability – Coniptical: A compromise between ice accretion characteristics and hail ingestion capability

Conical

Elliptical

Coniptical

• Fan icing appears on leading edge and pressure face of the fan blades and decreases from the root to the tip (centrifugal effect)

-8EFLIGHTOPS.PPT

NOTES

192

Spinner Ice Build Up, CFM56-5A

-8EFLIGHTOPS.PPT

NOTES

193

Spinner Ice Build Up, CFM56-3

-8EFLIGHTOPS.PPT

NOTES

194

Fan Blade and OGV Ice Build Up, CFM56-3

-8EFLIGHTOPS.PPT

NOTES

195

Icing (Continued) • Effects on engine – Operability • Ice ingestion into HPC may cause compressor stall, power loss, etc.

– Engine hardware • Ice slab ingestion may cause damage to fan or compressor – External source – Late application of engine anti-ice

• Ice shed from fan or spinner may cause acoustic panel or fan blade tip damage • Asymmetric ice accretion on the fan and spinner may cause high vibration

-8EFLIGHTOPS.PPT

NOTES

196

Icing (Continued) • Recommendations – – – –

Anti-ice system protects inlet cowl lip only Use engine anti-ice during all defined icing conditions Turn on anti-ice prior to entering icing conditions Perform ice shed procedure as prescribed in aircraft operations documents – If ice is inadvertently allowed to accumulate on the inlet • Retard one engine at a time to idle before turning A/I on • Turn A/I on, monitor engine while increasing thrust

-8EFLIGHTOPS.PPT

NOTES

197

Icing (Continued) Removal of Ice/Snow Prior to Engine Start - Recommendations De-ice inlet, spinner and fan prior to engine start – Use hot air if practical • Ensure any melted ice/snow does not refreeze near fan blades (check for fan rotation prior to engine start)

– De-icing/anti-icing fluid may be used if hot air de-icing is not practical • Engine must be off • Avoid spraying de-icing/anti-icing fluid into engine compressor

– Do not spray de-icing/anti-icing fluid into a running engine • May cause “hot corrosion” of turbine components • May result in increased maintenance costs

– If fan/spinner cannot be deiced prior to starting, use fan/spinner ice shedding procedures prior to takeoff • May result in economic damage to engine -8EFLIGHTOPS.PPT

NOTES

198

Icing (Continued) Ice Shedding (Ground) • Ground operation in icing conditions – During ground operations of more than 30 minutes in icing conditions or if excessive fan vibration due to fan ice accumulation is present, increase to approximately 54 percent N1 and hold at that thrust level for 30 seconds or until fan vibration level returns to normal • Allows immediate shedding of fan blade root and spinner ice • De-ices stationary vanes with combination of shed ice impact, pressure increase and adiabatic temperature rise (typical rise across fan is about 20°F)

– Perform this procedure • Every 30 minutes • Just prior to or in conjunction with the takeoff procedure, with particular attention to engine parameters prior to final advance to takeoff thrust

-8EFLIGHTOPS.PPT

NOTES

199

Icing (Continued) Ice Shedding (Flight)

• While in moderate or severe icing conditions and – If fan ice build up is suspected (high indicated or perceived vibration): • One engine at a time, reduce towards idle then advance to a minimum of 70% N1 for 10 to 30 seconds, then return thrust lever to position required for flight conditions

– Repeat every 15 minutes or as often as required

-8EFLIGHTOPS.PPT

NOTES

200

Typical CF6 Icing Event • Low power descent caused ice build-up • When power applied at level off, ice started shedding and vibs increased dramatically at about 70% • Vibs reduced with further acceleration and subsequent deceleration

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201

Typical CF6 Icing Event (Continued) Ice shed point

100 90

9

80

8

70

7

60

%N1

10

6

N1

50

5

40

4

30

3

20

2

10 0

1

Fan vibes 0

20

40

Fan vibes (units)

60

80

100

120

140

160

180

0

Time (seconds) -8EFLIGHTOPS.PPT

Indications on other engine models would be similar.

NOTES

202