AIRCRAFT GROUND HANDLING GENERAL BRIEFING
V1.0
21 January 2007
AIRCRAFT GROUND HANDLING
TABLE OF CONTENTS SEATING ...........................................................................................................3 HEAD UP GUIDANCE SYSTEM (HGS) ............................................................3 PRIOR TO TAXI.................................................................................................3 VEHICULAR TRAFFIC ......................................................................................3 SAFETY AND COMFORT .................................................................................3 TAXI SPEED......................................................................................................4 TILLER USE AND LEADING .............................................................................4 STOPPING ........................................................................................................6 REVERSAL TURNS AND RUNWAY LINE UP ..................................................7 TERMINAL GUIDANCE.....................................................................................7 FUEL CONSERVATION ....................................................................................8 CONCLUSION ...................................................................................................8 Page 1 of 8
AIRCRAFT GROUND HANDLING GENERAL BRIEFING
V1.0
21 January 2007
Revision Record
Version
Date
V1.0
21/01/07
Source
Change
Reason
Page/s
Original Issue
N/A
All
P. Donazzan
Disclaimer: This briefing remains the property of QANTAS. Copying for other than student’s own use is illegal. The subject content of this brief is correct at the time of publishing. In any case, the Flight Crew Operations Manuals are the authoritative documents. It is the responsibility of users to ensure that they are aware of changes or corrections to subject matter circulated by QANTAS.
Page 2 of 8
AIRCRAFT GROUND HANDLING GENERAL BRIEFING
V1.0
21 January 2007
SEATING Instruction in aircraft ground operation begins with emphasis on correct seat and rudder pedal positioning. Adjust the seat first, then the rudder pedals. Most aircraft have correct eye position indicators (refer to type specific manuals), these should be used to determine the optimum seat position. It is important that these positions are remembered so that seat changes in the air may be made easily and individual seat position restored consistently. The pilot must feel comfortable, in addition to having the correct forward view and access to full simultaneous rudder and brake application.
HEAD UP GUIDANCE SYSTEM (HGS) If the aircraft has HGS fitted, inhibiting the symbology at night whilst taxiing will provide an uncluttered view. Even by day some difficulty may be encountered, particularly using taxi in guidance systems, due to the overlying symbology.
PRIOR TO TAXI The Park Brake should not be released until: . • All personnel and equipment are clear • Following a pushback, the Nose Wheel Steering (NWS) pin has sighted . • ATC taxi clearance has been received and discussed . • Appropriate lighting is set • Both pilots have visually confirmed and cross-checked that no obstructions are in the taxi path.
VEHICULAR TRAFFIC All flight deck crew must not only remain vigilant to aircraft traffic when taxiing but also to vehicular traffic. At most airports there is significant vehicular traffic within apron areas and airport environs in general. It should be noted that such traffic is often not in contact with ATC or aircraft and occurrences of holding point/line overrun is frequent and poses a significant risk to aircraft.
SAFETY AND COMFORT A prime consideration during taxi is safety and passenger/crew comfort. Crew injuries
have occurred with overly harsh braking or turning input by the taxiing pilot. Be aware that passengers and crew will judge us by the smoothness of input on the ground, as well as in the air. Instructors should emphasise the importance of Page 3 of 8
AIRCRAFT GROUND HANDLING GENERAL BRIEFING
V1.0
21 January 2007
smooth taxiing by describing the correct use of brakes, tiller and rudder pedal steering. Small movements on the flight deck are amplified in the cabin. Key issues to consider include the difficulty in accurately assessing forward speed from high flight decks and the significance of aircraft geometry which relates pilot eye position to that of the nose gear and main gear when manoeuvring. Be cognisant of the effects of jet blast on ground personnel and equipment, particularly when using breakaway thrust. Some ports such as the Gold Coast are taxi in, taxi out, so also be aware of passengers moving towards other aircraft on the tarmac. It is essential that both pilots, prior to taxi commencement, check that the tarmac is clear. Some aircraft at light weights only require idle thrust to commence movement, whereas at heavier weights a small amount of thrust above idle (40% N1dependant on type) is necessary to get the aircraft moving. Idle thrust is generally adequate for subsequent taxiing unless the aircraft is heavy or taxiing uphill.
TAXI SPEED Individual Type FCTM provide guidance on maximum taxi speeds. Anticipation of the added deceleration distance required from higher taxi speeds is paramount. Ground speed readout should be used to ensure that maximum recommended speeds for taxi are not exceeded, especially during turns. On a dry, level surface, use approximately 10 knots maximum for turn angles greater than 30 degrees. Conversely on a slippery surface 3-5 knots may be the appropriate maximum speed for turning. If behind schedule, significant time saving can be achieved by taxiing at a speed close to the aircraft’s recommended maximum. This is, of course, dependent upon airport congestion and should only occur on straight taxiways. Correct use of brakes to avoid excessive brake wear and heat accumulation must be thoroughly understood. Carbon brake wear is dependent on the number of brake applications and on brake temperature. Allowing the aircraft speed to build up towards maximum then gently apply the brakes to decelerate to approximately 15 knots will reduce the number of brake applications. Correct turning technique and use of body gear steering (where fitted) will minimise stress and side loads on landing gear structures. Be aware that wet painted surfaces can be slippery.
TILLER USE AND LEADING The tiller is used for large turning inputs, while pedal controlled nose wheel steering (as fitted) is used on straight taxiways. Page 4 of 8
AIRCRAFT GROUND HANDLING GENERAL BRIEFING
V1.0
21 January 2007
Fly By Wire (FBW) aircraft have specific considerations such as: . • non-linear tiller deflection versus nosewheel steering angles . • inherent light tiller forces . • a preset maximum rate of nosewheel movement, irrespective of rate of tiller movement. Ideally a turn should not be commenced until sufficient forward speed has been attained to carry the aircraft through the turn at idle thrust.
“Leading” is the technique whereby input to the tiller is initially introduced in a gradual manner. This is to prevent jerking or in extreme cases nose wheel scrubbing. Nose wheel scrubbing occurs when the nose wheel loses traction due to excess speed and/or nose wheel angle. This is felt as a rumble. If this occurs reduce tiller input and /or forward speed. After the turn is commenced the rate of tiller deflection is increased to achieve the required turn rate. All the airports that Qantas operate to have no single standard of obstacle clearance for taxiway design. Thorough examination of airport aerodrome charts and notes together with supplemental information from Notams and Route Manual Supplement (RMS) will provide some of the information you require for safe taxiing. Your fellow crewmembers and training personnel will also inform you of their experiences, so use your crew as a resource on the ground as well as in the air. Figure 2.1, below, is an extract from ICAO annex 14 on recommended design standards for taxiways, which will become mandatory on 20 November 2008. As can be seen from this diagram, the intention of this design is that the cockpit be kept over the centreline. Unfortunately, there is no way of telling to which standard a taxiway is designed. Where no suitable widening is provided on a bend, the cockpit may need to be positioned outside of the taxiway centreline to assure main gear remains on the taxiway. This can also be seen by the gear position in the turn in Figure 2.1.
Page 5 of 8
AIRCRAFT GROUND HANDLING GENERAL BRIEFING
V1.0
21 January 2007
Figure 2.1 Thus it is essential for avoiding obstacles that the aircraft is taxied on the taxiway centreline. If taxiing on a straight leg, the nosewheel is generally on the centreline if you extend the taxiway centreline markings back in line with the leg closest to the centre console. The instructor should assist in this by describing the correct visual cues to align the aircraft on the centreline on your type. Do not attempt to avoid an obstacle by deviating off the centreline. Stop the aircraft and wait for the obstacle to be removed. When turning remember that the outside wing travels outwards significantly (approximately 5m depending on type). For this reason oversteer may be necessary to avoid an obstacle on the inside of the turn or for the main gear to remain on the taxiway. But be aware that oversteer reduces the clearance of the outside wing considerably. When any doubt exists, as to engine or wing tip clearance, stop the aircraft and await assistance.
STOPPING Taxiway stop lines are where the aircraft nose must not pass unless in receipt of a clearance. Anticipate the distance required to bring the aircraft to a halt and apply gradual brake pressure to provide a comfortable deceleration to a smooth, Page 6 of 8
AIRCRAFT GROUND HANDLING GENERAL BRIEFING
V1.0
21 January 2007
gentle stop. The stopping forces can be further reduced by a reduction in the brake pedal pressure just as the aircraft comes to a halt. Once the aircraft has stopped, a check outside the side window will confirm that there is no forward movement prior to Park Brake application. Note, a check of ground speed readout alone is not sufficient due to possible residual errors
REVERSAL TURNS AND RUNWAY LINE UP For most taxi manoeuvres asymmetric thrust is not required. However tight turns, including reversal turns may require asymmetric thrust. When carrying out reversal turns on a limiting runway emphasis should be placed on smooth and up to full application of nose wheel steering. Keep the aircraft rolling, while avoiding nose wheel scrubbing due to excess speed. Use only sufficient differential thrust to maintain momentum through the turn. The amount of thrust will depend on aircraft gross weight, runway surface and ambient conditions, but should rarely exceed 40 50% N1. The nose wheel should be centred on completion of the turn to prevent stress on the nose wheel assembly. Rather than use runway distance establishing precisely on the centreline, it may be desirable to align the aircraft so that the centreline is regained some distance down the runway during the takeoff roll. Avoid setting takeoff thrust until generally aligned with the runway. Be aware that taxi lines from the holding point to the runway, are usually for taxi off guidance and that by following them available takeoff distance may be reduced. Conversely, a hard 90 degree turn on to the runway centreline would only be required if at or approaching field length limit conditions. Be aware of aircraft momentum and attempt to minimise runway occupancy time.
TERMINAL GUIDANCE To control and guide the aircraft towards the aerobridge at the terminal, various stop bar systems are used and these must be studied prior to their use. Jeppesen Terminal Charts normally provide this information. If the guidance/stopbar system is turned off or fails, the aircraft must be brought to a smooth halt immediately. If the stop bar is inadvertently overrun, a tug must be used to push the aircraft back to the correct position. Passengers must be seated with the seat belt sign illuminated if this is required, so ensure an appropriate P.A. is made. This also applies if the aircraft is to be towed onto the gate. Reverse thrust is prohibited from being used to reverse the aircraft.
Page 7 of 8
AIRCRAFT GROUND HANDLING GENERAL BRIEFING
V1.0
21 January 2007
FUEL CONSERVATION Fuel conservation is also an important consideration during taxi operations. Be aware of ground traffic congestion and adjust taxi speed to avoid unnecessary stops and subsequent breakaway thrust usage. Taxi-in with one engine shut down (where applicable) by following the applicable FCOM procedure. Thus small fuel savings can be made on each sector and when applied to the whole Qantas fleet, significant savings are realised.
CONCLUSION Smooth and safe aircraft handling requires good planning, lookout and anticipation. Take equal pride in it as you do your airborne performance.
Page 8 of 8
