Landing Gear & Brakes Flashcards
OFF position of the landing gear lever does what?
Depressurizes landing gear hydraulic system.
Nose Wheel Steering range with rudders?
7 degrees
Total turning range using tiller and rudder control?
70 degrees
When are AUTOBRAKES/RTO armed? When do they activate?
- Armed on the ground by selecting RTO
- A/C on ground
- Above 85 knots
- All TL CLOSED
BRAKE SOURCE Light?
HYD SYS 4, 1, & 2 have LO PRESSURE
Amber X on an expanded gear position indicator means?
Landing gear position indicator INOP
What sensing systems, related to gear, control flight/ground ops of systems?
- Air/Ground Sensors
- Nose Gear Extension Sensing System
How does A/C distinguish between air/ground mode?
Combination of main gear tilt sensors
Nose gear extension sensing provides signal to relays functioning which systems?
- Stall warning
- Nose Gear steering
What conditions must be satisfied for gear lever lock to release for retraction?
- Main gear tilted
- Body gear centered
Landing Gear UP sequence of events?
- Doors Open
- Auto braking occurs
- Gear begins retraction
- Main gear hydraulically tilt to retract position
- EICAS displays indication
How is gear held UP?
Main Gear - uplocks
Nose Gear - mechanically
During gear movement, what happens if any gear position disagrees with lever position after normal transit time?
- EICAS changes to non-normal format
- Affected gear displays as in transit
- Displays UP if never unlocked
Alternate gear extension sequence?
- Push alternate gear extend switches
- Gear uplocks/door latches electrically released
- Gear free falls
- Gravity extends gear
- Springs pull downlocks into locked position
- Gear doors remain open
When does body gear steering operate?
- Nose wheel steering angle +20 deg
- Ground speed decreasing through 15 kts
When is body gear steering deactivated?
Ground speed increasing through 20 kts
Purpose of brake accumulator?
Parking brake application
How does normal anti-skid provide protection?
Provides anti-skid to each main gear wheel individually. When skid is detected, associated valve reduces brake pressure.
How does alternate anti-skid system provide protection?
Provides protection to lateral wheel pairs rather than individually.
Brake torque limiter function in Alternate brake system?
- Brake torque is sensed on individual wheel basis however, brake pressure released on laterally paired wheel basis
When do autobrakes apply after landing?
- On Ground
- Wheels spun up
- All TL CLOSED
Ways to disarm autobrakes after landing?
- Pedals
- TL advance
- Speedbrake Lever to DOWN
- Selector to DISARM or OFF
- Autobrake fault
- Antiskid fault
Brake accumulator HYD SYS?
SYS 4
Why is HYD SYS 4 pressurized first?
Precludes the transfer of hydraulic fluid from SYS 1 or 2 into SYS 4 when parking brake is set and released.
- First HYD SYS pressurized will always return a small amount of fluid to HYD SYS 4
What value causes BRAKE TEMP message on EICAS?
Greater than or EQUAL TO 5 units
Is autobrake system available when alternate braking system is in use?
No, only primary.
All gear doors contain both ____ and ____ actuation?
Hydraulic and Mechanical:
- Wing Gear = 1 HYD & 1 MECH
- Body Gear = 1 HYD & 2 MECH
- Nose = 2 HYD & 2 MECH
Landing gear DOWN sequence of events?
- Doors open
- Gear are unlocked
- Gear hydraulically powered DOWN
- Door close
- Main gear trucks tilt to flight position
What EICAS landing gear position displays when alternate extension system is used?
Expanded gear position indication.
Nosewheel and body gear steering HYD SYS?
HYD SYS 1
What happens to body gear as speed increases through 20 knots?
Hydraulically centered
Do nose wheel have brakes installed?
NO
Normal braking HYD SYS?
HYD SYS 4
If HYD SYS 4 pressure is low for braking, what happens?
HYD SYS 1 supplies pressure to the alternate brake hydraulic system.
Placing AUTOBRAKES selector in DISARM does what?
- Disengages autobrake
- Releases brake pressure
Brake temp values on EICAS range from?
0 to 9
With regards to gear position indications, white crosshatch means?
In transit
AUTOBRAKES are only available when what braking system is functioning?
Primary, meaning HYD SYS 4 providing system pressure.
Is antiskid protection provided during AUTOBRAKE operation?
Yes, of course you idiot.
Alternate braking system simply means?
HYD SYS 4 was low and HYD SYS 1 is now providing pressure to braking system.
AUTOBRAKE upon landing provides braking until?
Complete stop or system disarmed.
When AUTOBRAKE system is disarmed upon landing (by using pedals braking for instance), where does selector move to?
DISARM
Where does AUTOBRAKE selector move to during takeoff?
Remain in RTO, even if disarmed. Moves to OFF after takeoff.
What decides which HYD SYS controls braking application?
Pressure operated selected valves
Is the RTO function of the AUTOBRAKES system available under 85 knots?
NO
Difference between OFF and DISARM switch positions on AUTOBRAKE PANEL?
- OFF will disarm and reset system
- DISARM will disarm system and release all brake pressure to the wheels.
When do AUTOBRAKES engage after touchdown?
- Weight on wheels
- Wheels spin up
- ALL Thrust Levers CLOSED
