Landing gear Flashcards
Which system control landing gear extension, retraction and sequencing of the doors?
Two LGCIUs (Landing Gear Control and Interface Units)
When is control switched from one LGCIU to the other?
- In case of failure
- At the completion of one complete gear cycle at retraction.
Which hydraulic system actuates the landing gear and doors?
Green
When does the safety valve close?
> 260kts or with the MLG on the ground
How many sets of proximity sensors are there?
One set for each LGCIU
What happens when turning the gravity extension crank?
- Landing gear hydraulics isolated from green system
- Door and landing gear unlocked
- Gravity drops the gear in to extended position
Will the doors close following gravity extension?
No
Which LGCIU is connected to the Landing Gear Indicator Panel?
LGCIU 1
What is the significance of the red UNLK light?
Gear is not locked in the selected position
What is the max nose wheel steering angle?
+/-6° from rudder pedals
+/-75° from hand wheel
Which hydraulic system actuate the NWS?
Yellow
When does the NWS receive hydraulic pressure?
- A/SKID NWS switch ON
- Towing lever in normal position
- One engine running
- On the ground
Which hydraulic system is used for the normal brakes?
Green
Which hydraulic system is used for the alternate brakes?
Yellow, backed up by hydraulic accumulator
Can the MAX autobrake setting be used on ground and in flight?
Only on ground
When does the BSCU change channel?
At each down selection of landing gear
What failure modes can the brakes revert to?
- Alternate brakes with antiskid
- Alternate brakes without antiskid
- Alternate brakes without antiskid on accumulator
What is compared with the wheel tachometer for antiskid protection?
Aircraft reference speed from ADIRU 1,2 or 3
Can the auto brakes be used with antiskid inoperative?
No
When is autobrake activated?
When a command for ground spoilers is detected
How can the autobrake system be manually disarmed/deactivated
- Ground spoilers retract
- Pushbutton off
- Deflection of brake pedal
Which hydraulic system provides pressure for the alternate brakes?
Yellow
Can auto brakes be used with alternate brakes?
No
Do alternate brakes need to be selected manually?
No
How many full brake applications are available on accumulator pressure?
7
What is the brake pressure limited to when using alternate brakes without antiskid?
1000psi
When is brake pressure indicated on the BRAKES and ACCU PRESS indicator?
Only when the yellow system controls the brake pressure
- Alternate braking activated
- Parking brake applied
When does the DECEL light illuminate?
When actual deceleration rate is >80% of commanded
Which hydraulic system provides pressure to the parking brake?
Yellow system or accumulator
For how long will the accumulator maintain parking brake pressure?
Minimum 12h
Will the A/SKID NWS switch position affect the normal brakes?
Yes. Switch off will also deactivate the normal brakes
What is VLE?
280 kts
What is the effect of initiating a rejected takeoff at low speed (<72kts)?
Autobrakes will not activate due to no spoiler deployment <72kts.
What is Vlo?
Extension: 250kts
Retraction: 220kts
