Landing Gear and Brakes - Question Bank Flashcards
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? (From down–> up position)
- 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?
- Ground speed decreasing through 15 knots
* 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
Can the airplane be stopped with normal accumulator pressure?
No, the accumulator is not designed to stop the aircraft.
Why is it necessary to pressurize hydraulic system 4 before pressurizing the other systems?
Precludes the transfer of hydraulic fluid from system 1 or 2 into system
4, when the parking brake is set, and then released.
What provides automatic brake source selection?
Pressure-operated selector valves
What value on the brake temperature monitoring system causes the BRAKE TEMP Advisory EICAS message to appear?
5
