787 Flight Crew Operations Manual
DO NOT USE FOR FLIGHT
Landing Gear -
System Description
Copyright © The Boeing Company. See title page for details.
D615Z003-TBC 14.20.3
Following an alternate extension, the landing gear can be retracted by the center
hydraulic system, if it is operating. Select DN then UP with the gear lever to
retract the landing gear.
Nosewheel Steering
The airplane is equipped with nosewheel steering powered by the center hydraulic
system.
Primary steering control is provided by a nosewheel steering tiller for each pilot.
Limited steering control is available through the rudder pedals. The tillers can turn
the nosewheels up to 70º in either direction. A pointer on the tiller assembly shows
tiller position relative to the neutral setting. The rudder pedals can be used to turn
the nosewheels up to 8º in either direction. Tiller inputs override rudder pedal
inputs.
Brake System
Each main gear wheel has a multiple disc carbon brake. The nosewheels have no
brakes. The brake system includes:
• electric brake system
• antiskid protection
• autobrake system
• parking brake
Electric Brake System
The brake system is powered by four electric brake power supply units. The brake
pedals provide independent control of the left and right brakes.
Four Electric Brake Actuators (EBAs) are provided on each main landing gear
wheel brake to control the application of braking force to the carbon disc. The
EBAs are controlled by an Electric Brake Actuator Controller (EBAC). There are
four EBACs that control all eight main wheel brakes, each EBAC controlling the
brake force of a fore-aft wheel pair.
Antiskid Protection
Antiskid protection is provided on an individual main gear wheel basis. When a
wheel speed sensor detects a skid, the braking force is reduced until skidding
stops.
Touchdown and hydroplaning protection is provided using airplane inertial
groundspeed. Locked wheel protection is provided using a comparison with other
wheel speeds.
The EICAS advisory message ANTISKID is displayed if an antiskid fault
affecting the brake system is detected or if the system is completely inoperative.
February 15, 2010
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