GOL 737-8, Руководство по эксплуатации, Страница: 1763 / 1826

737 MAX Flight Crew Operations Manual
Landing Gear -
System Description
MN-FLT-OH-201 14.20.3
Nose Wheel Steering
Nose wheel steering is available when the nose gear is in the down position and
compressed by weight of the airplane. Positioning the landing gear control lever
to down makes system A hydraulic pressure available to the steering metering
valve. Alternate nose wheel steering can be activated to provide system B pressure
to the nose wheels when the NOSE WHEEL STEER switch is placed to ALT,
normal quantity is in the system B reservoir, and the airplane is on the ground. In
the event of a hydraulic leak downstream of the Landing Gear Transfer Unit,
resulting in a loss of hydraulic system B fluid in the reservoir, a sensor closes the
Landing Gear Transfer Valve and alternate steering will be lost.
Primary steering is controlled through the nose wheel steering wheel. Limited
steering control is available through the rudder pedals. A pointer on the nose
steering wheel assembly shows nose wheel steering position relative to the neutral
setting. Rudder pedal steering is deactivated as the nose gear strut extends.
A lockout pin may be installed in the towing lever to depressurize nose wheel
steering. This allows airplane pushback or towing without depressurizing the
hydraulic systems.
Brake System
Each main gear wheel has a multi–disc hydraulic powered brake. The brake pedals
provide independent control of the left and right brakes. The nose wheels have no
brakes. The brake system includes:
Normal Brake System
The normal brake system is powered by hydraulic system B.
Alternate Brake System
The alternate brake system is powered by hydraulic system A. If hydraulic system
B is low or fails, hydraulic system A automatically supplies pressure to the
alternate brake system.
Brake Accumulator
The brake accumulator is pressurized by hydraulic system B. If both normal and
alternate brake system pressure is lost, trapped hydraulic pressure in the brake
accumulator can still provide several braking applications or parking brake
application.
• normal brake system
• alternate brake system
• brake accumulator
• antiskid protection
• autobrake system
• parking brake
1B785, 1J585 - 1J594 • brake temperature indication
March 1, 2021