Landing Gear/Flight Controls Flashcards
How does the gear extend/retract?
The hydraulic selector valve actuated by the cockpit lever releases the locks, directing pressure to unlock the main gear and inboard doors. The gear extends and the last movement of the actuators locks the main gear stay and nose gear drag brace. The main gear inboard doors close, the nose gear doors close, and the aft door remains open.
To retract, the gear selector valve directs opening the main gear inboard doors and disengages the downlocks. The main gear inboard doors hydraulically close and lock; the nose gear doors are mechanically closed.
How is the nosewheel steering controlled? How much does it deflect?
Manually controlled, hydraulically actuated by the tiller, provides 45° deflection left and right of center
When is nosewheel steering available?
When main hydraulic pressure is 2,300 psi or greater - the aux hydraulic system cannot drive the nosewheel steering
How are the brakes operated in normal and emergency condition?
Controlled by master cylinder on each rudder pedal
What does each wheel include to relieve pressure?
Fusible plugs
What must be installed on the nose gear prior to taxi?
Steering disconnect pin
What prevents retraction of all three landing gear on the ground?
Gear pins inserted into the landing gear
How is retraction and extension of the landing gear controlled in the cockpit?
Mechanical lever that actuates a hydraulic selector valve
What do 3 green lights indicate for the landing gear?
Gear down and locked
What do 3 red lights indicate for the landing gear?
Gear in transit, gear unlocked
What do 3 green and 3 red lights indicate for the landing gear?
Gear down and locked with the landing gear lever out of down position
What do no lights indicate for the landing gear?
All gear up and locked
How is landing gear position monitored in case of indicator lights failure?
Green annunciators under a hinged door on the FO’s side panel for the mains, and a mechanical indicator pin on center pedestal for the nosewheel
What are 3 situations that cause the gear horn to sound? Can they be overridden?
- Gear not down and flaps 25°, 45°: cannot be overridden
- Gear handle not down when the aircraft is on the ground and starter bus powered: cannot be overridden
- Gear not down and thrust lever angle below 60-70% N1 and airspeed below 150 KIAS: can override
What controls emergency extension of the landing gear? How is it activated?
The auxiliary hydraulic system closes the hydraulic on-off valves, opens a dump valve, and allows hand pump operation
How are braking operations controlled? (Not actual braking with the pedals)
Through the WHEEL BRAKE lever on the center pedestal
How do the brakes respond with the WHEEL BRAKE lever set to NORMAL?
Normal braking action - pressure on master cylinders through the rudder brakes control valve for braking, anti-skid available
How do the brakes respond with the WHEEL BRAKE lever set to EMERG?
Emergency accumulator activates to provide braking pressure (~ 18 applications of braking power), no anti-skid available, normal actuation of brakes through rudder braking
How do the brakes respond with the WHEEL BRAKE lever set to PARK BRAKE?
Uses pressure from main and emergency accumulators to hold the brakes stationary
What provides anti-skid? What type of anti-skid system is it?
The Maxaret system provides mechanical anti-skid
How does the Maxaret system provide anti-skid?
Entirely mechanical, no electrical input - reduces/releases brake pressure in the event of a skid, not functional until wheels begin to spin
What does a white L/R EMERG WHEEL BRAKE annunciator indicate?
Indicates 1,000 psi of pressure of greater applied to brakes with WHEEL BRAKE lever in EMERG or PARK BRAKE position
What is V LO of the landing gear?
220 KIAS
What is V LE of the landing gear?
220 KIAS
What are the rejected takeoff limitations regard brakes?
- 1st RTO (below 90 KIAS): 25 minute cooling period
- 2nd RTO (below 90 KIAS): 45 minutes cooling period
- Any subsequent RTO (below 90 KIAS): 45 minutes cooling period
- Any RTO 90 KIAS or greater: brake inspection required
Inadvertent landing gear retraction on the ground is prevented by:
A solenoid-operated device engaging the selector lever