Landing Gear & Brakes *** Flashcards
(52 cards)
Describe the OFF position of the landing gear.
• Landing gear hydraulic system is depressurized.
How many degrees can the nose-wheel steering system turn the nose gear with the tiller, and how many degrees with the rudder pedals?
- 70 degrees in either direction with the tiller
* 7 degrees with the rudder pedals
When does RTO apply maximum brake pressure?
- Airplane on the ground
- All 4 thrust levers are closed, and
- Above 85 knots.
What does the BRAKE SOURCE amber light indicate when illuminated?
• Active brake hydraulic sources (hydraulic systems 4, 1, and 2) have low pressure
What does a white, crosshatched, expanded gear position indication mean?
• Respective landing gear in transit
What does an amber X display on an expanded gear position mean?
• Landing gear position indicator inoperative
What does a white empty box on the Gear synoptic display indicate?
• Respective landing gear door position indicators inoperative
What sensing systems control in flight and ground operation of various airplane systems?
- Air/ground sensing system
* Nose gear extension sensing system
How does the airplane distinguish between air mode and ground mode?
• A combination of main gear tilt sensors
Nose gear extension sensing provides a signal to relays controlling functions
in which systems?
- Stall warning
* Nose gear steering
What conditions must be satisfied in order for the landing gear lever lock to release?
- Main gear are tilted
* Body gear centered
Describe the sequence of events when the landing gear lever is moved UP.
- The landing gear doors open
- Automatic braking occurs
- Landing gear begin to retract.
- EICAS gives related indications
How are the landing gear held in position after retraction?
- Main gear are held in the up position by uplocks
* The nose gear is mechanically locked in the up position.
During landing gear extension, state what happens if any gear position disagrees with lever position after normal transit time.
• The EICAS changes to the expanded non-normal format
• Affected gear displayed as in transit, or UP if the gear never unlocked
from the up position.
How does the gear extend through the alternate gear extension system?
- By pushing the Alternate Gear Extend switches
- The gear uplocks and gear door latches are electrically released.
- The gear free-falls
- Gravity and air loads extend the gear
- Springs pull the downlocks into the locked position
When does body gear steering operate?
• When the nose wheel steering angle exceeds 20 degrees
When is body gear steering activated and when is it deactivated?
- Activated Ground speed decreasing through 15 knots
* Deactivated Ground speed increasing through 20 knots
What is the purpose of the brake accumulator?
• Provides parking brake application
Describe the difference between normal and alternate anti-skid braking systems.
• Normal brake antiskid provides each main gear wheel with individual
antiskid protection.
• Alternate brake antiskid provides antiskid protection to lateral wheel pairs
(forward and/or aft pair on each truck), rather than to individual wheels
How does the brake torque limiter function in the Alternate brake system?
- Brake torque is sensed on an individual wheel basis.
- Signal sent to alternate anti-skid valve.
- Brake pressure is released on a laterally paired wheel basis.
When do the auto brakes apply after landing?
- All thrust levers are closed
- Ground mode sensed
- The wheels have spun up
Which systems contribute to total airplane deceleration on landing and reduces autobrake pressure?
- Thrust reverse
* Spoilers
Give examples of what would disarm the autobrakes after landing.
• Pedal braking applied
• Any Thrust lever advanced after landing
• Speedbrake lever moved to DOWN detent after speedbrakes have been
deployed on the ground
• DISARM or OFF position selected on the Autobrakes selector
• Autobrake fault
• Normal antiskid system fault
• Loss of normal hydraulic pressure
What hydraulic system pressurizes the brake accumulator?
• System 4
