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ensuring that the thrust on the engines advances symmetrically. Any tendency to
deviate from the runway centerline must immediately be countered with steering
action and, if required, slight differential thrust.
October 31, 2006
777/787 Flight Crew Training Manual
Takeoff and Initial Climb
Copyright © The Boeing Company. See title page for details.
FCT 777/787 Preliminary (TM) 3.21
Forward pressure on the control column during the initial portion of the takeoff
roll (below approximately 80 knots) increases nose wheel steering effectiveness.
During takeoffs on icy runways, lag in rudder pedal steering and possible nose
wheel skidding must be anticipated. Keep the airplane on the centerline with
rudder pedal steering and rudder. The rudder becomes effective between 40 - 60
knots. If deviations from the centerline cannot be controlled either during the start
of the takeoff roll or until the rudder becomes effective, immediately reject the
takeoff.
Federal Aviation Regulation (FAR) Takeoff Field Length
The FAR takeoff field length is the longest of the following:
• the distance required to accelerate with all engines, experience an engine
failure 1 second prior to V1, continue the takeoff and reach a point 35 feet
above the runway at V2 speed. (Accelerate-Go Distance).
• the distance required to accelerate with all engines, experience an event 1
second prior to V1, recognize the event, initiate the stopping maneuver
and stop within the confines of the runway (Accelerate-Stop Distance).
• 1.15 times the all engine takeoff distance required to reach a point 35 feet
above the runway.
Stopping distance includes the distance traveled while initiating the stop and is
based on the measured stopping capability as demonstrated during certification
flight test.
During certification, maximum manual braking and speedbrakes are used. Thrust
reversers are not used. Although reverse thrust and autobrakes are not used in
determining the FAR accelerate-stop distance, thrust reversers and RTO
autobrakes should be used during any operational rejected takeoff.
Calculating a V1 speed that equates accelerate-go and accelerate-stop distances
defines the minimum field length required for a given weight. This is known as a
“balanced field length” and the associated V1 speed is called the “balanced V1”.
The FMC provides takeoff speeds based on a balanced V1. If either an ATM or
fixed derate reduced thrust takeoff is used, the FMC, if FMC takeoff speeds are
available, will provide a balanced V1 applicable to the lower thrust setting.
Takeoff gross weight must not exceed the climb limit weight, field limit weight,
obstacle limit weight, tire speed limit, or brake energy limit. If the weight is
limited by climb, obstacle, or brake considerations, it may be beneficial to use
takeoff speeds that are different from the normal balanced takeoff speeds provided
by the FMC. Examples of this include the use of:
• improved climb to increase climb or obstacle limited weights
• maximum V1 policy to increase obstacle limited weights
October 31, 2006
777/787 Flight Crew Training Manual
Takeoff and Initial Climb
Copyright © The Boeing Company. See title page for details.
3.22 FCT 777/787 Preliminary (TM)
• minimum V1 policy to increase brake energy limited weights
• clearway or stopway to increase field or obstacle limited weights.
If the takeoff weight is not based on normal balanced V1, the FMC takeoff speeds
are not applicable and the operator should provide the pilot with a method to
obtain the appropriate takeoff speeds.
FAR Takeoff
Rejected Takeoff Decision
The total energy that must be dissipated during an RTO is proportional to the
square of the airplane velocity. At low speeds (up to approximately 80 knots), the
energy level is low. Therefore, the airplane should be stopped if an event occurs
that would be considered undesirable for continued takeoff roll or flight.
Examples include Master Caution, unusual vibrations or tire failure.
Note: Refer to the Rejected Takeoff NNM in the QRH for guidance concerning
the decision to reject a takeoff below and above 80 knots.
As the airspeed approaches V1 during a balanced field length takeoff, the effort
required to stop can approach the airplane maximum stopping capability.
Therefore, the decision to stop must be made before V1.
Historically, rejecting a takeoff near V1 has often resulted in the airplane stopping
beyond the end of the runway. Common causes include initiating the RTO after
V1 and failure to use maximum stopping capability (improper
procedures/techniques). Effects of improper RTO execution are shown in the
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787机组训练手册Flight Crew Training Manual 787(40)
