Landing Gear Flashcards
In which direction does the gear retract
The Landing Gear (LG) consists of two inward retracting main gears and a forward retracting nose gear
Which hydraulic system supplies landing gear operation
Hydraulic system 1
How is landing gear locked down
The main gears are mechanically locked down.
Are there any landing gear up locks
No
How is the landing gear held in the retracted position
The main gears are held in the retracted position by hydraulic pressure.
What happens to a retracted landing gear when the hydraulic power is lost
The main gears are held in the retracted position by hydraulic pressure. In the event of loss of hydraulic pressure, the main gears will rest on the doors. Outboard doors are connected to the main gear struts, and open and close mechanically
Which doors are hydraulically operated
All
What is the landing gear lever connected to
The LG selector operates a selector valve which directs hydraulic system 1 pressure in accordance with UP and DOWN selection
What are normal extension and retraction times
Extension time 26secs
Retraction time 9 secs
Can the landing gear selector be selected up on the ground
Inadvertent UP selection on the ground is prevented by an electrical LG selector lock
What light indications confirm normal operation
LG position lights are located below the LG selector. The LG down and locked position is indicated by a green light for each respective gear. The lights will be out when the LG is fully retracted. A blue light incorporated in the LG selector knob will come on during retraction until all LG doors are closed and locked, and during extension until all landing gears are down and locked. When the lights come on due to alternate LG extension it remains on until the LG selector is selected down
What will give a level 3 LANDING GEAR NOT DOWN alert can the alert be cancelled
A level 3 alerts is presented when the LG is not down and locked and the aircraft is in an approach configuration. The approach configuration is defined as a radio altitude less than 1000 ft and either a flap position greater than 23 degrees or a thrust lever position less than MIN TO
When would you use the LG OVRD button
In case essential/emergency power is selected ON, the LG OVRD button must be depressed in case of gear retraction, as the anti- retraction solenoid is powered by the dual DC bus. To eliminate the possibility of structural damage when one (or both) main landing gear strut(s) has (have) failed to extend, the use of the landing gear selector override button should be delayed until passing 400 ft AGL
What restriction is there on the operation of the LG OVRD button
To eliminate the possibility of structural damage when one (or both) main landing gear strut(s) has (have) failed to extend, the use of the landing gear selector override button should be delayed until passing 400 ft AGL
What does operation of the alternate landing gear lever do
Operation of the selector releases the locks of the LG doors, and dumps the LG hydraulic system pressure. The LG will then extend by gravity and m e c h a n i c a l l y lock d o w n
What happens to the main gear doors after an alternate selection
The main-gear i n board doors will stay open and are protected, against serious damage on landing, by slide strips
Nose wheel steering is powered by which hydraulic system
Hydraulic system 1
Is nose wheel steering available after an alternate extension
Nose-wheel steering becomes inoperative after alternate gear extension.
What steering angles are available from rudder input and tiller input
Rudder input 7 degrees either side of centre
Tiller input 76 degrees either side of centre
Where and when is nose wheel steering switched on and off
A towing switch, located next to the external power receptacle, can be used to depressurize the nosewheel steering system during maintenance round handling.
What happens if steering inputs exceed the normal limits
It castor till it is back to its normal range
What happens to the steering if the landing gear is selected down
Upon landing-gear-down selection, the steering system will be depressurized to prevent inadvertent steering angles while using the rudder pedals
What hydraulic system provides which brakes
Normal brakes hydraulic system 2
Alternate brakes hydraulic system 1
What happens if the system supplying the normal brakes looses pressure
Automatic change-over to alternate brake operation occurs when the pressure of hydraulic system 2 drops below a preset value
What is the minimum accumulator pressure for the alternate system
1000 psi
What is the diff between normal and alternate braking
Normal brake operation provides for skid protection on all four wheels individually.
Alternate brake operation pro- vides for skid protection on paired wheels on either side.
How do you test the anti skid
Press the anti skid test pb
What alert is there for anti skid
Anti skid fault
Level 2
What does operation of the parking brake handle do
The parking brake can be engaged by depressing either set of brake pedals and pulling the parking brake handle.
What visual indications do you have that the parking brake is set
A memo message is presented by MFDS whenever the parking brake is set
