Landing Gear & Brakes Questions Flashcards
How is the landing gear extended and retracted?
- Electrically commanded and hydraulically actuated.
When will the aural warning for the landing gear sound?
- If the gear is not down and locked, and
- < 700 RA and low TLA, or
- Any altitude with flaps set > 5
Can the landing gear aural warning be silenced by pushing the LG WRN INHIB button?
- Only if both radio altimeters have failed
What are three landing gear extensions modes?
- Normal LG lever DOWN
- Electric override Bypasses PSEM to direct command selector valve
- Alternate gear extension Manual uplock release opens free-fall sequencing valve
What is the purpose of the DN LOCK RLS button on the landing gear lever?
- Mechanically releases the landing gear lever lock
- Lock protects against inadvertent landing gear retraction when weight-on-wheels
What keeps the gear locked in position?
- Extended downlink springs
- Retracted Uplock hooks
Describe the landing gear indications?
- Green Down & Locked
- White Up & Locked
- Amber in transit
- Red gear position & Lever disagreement (20 sec grace period)
How do the landing gear doors actuate?
- Mechanically, during landing gear extension or retraction.
How are the brakes commanded?
- Fly-by-wire
- Electrically commanded and hydraulically actuated
- Pedal position transducers send brake request to the BCM (brake control module)
- What hydraulic systems provide brake pressure
- HYD 1 Outboard brakes
- HYD 2 Inboard brakes
- HYD 1 & 2 parking/emergency brake
What protections are provided for braking?
- 6 Applications
What stops the wheel from spinning during retraction?
- Main gear BCM applies brakes after weight-off-wheels
- Nose gear Snubbers in the nose bay stop the wheels
Which hydraulic system controls the nose wheel steering?
- HYD 2`
What are the limits for the nose wheel steering?
- Angle varies with ground speed
- Up to 40 its +76
- 41 to 100 its decreases linearly from 76 to 7
