Landing Gear

Question 1

Under normal conditions, which hydraulic system operates the lAnding gear?

Answer 1

Hydraulic System A

Question 2

Which hydraulic system(s) can pressurize the parking brake?

Answer 2

Either A or B during normal operations

Question 3

If the #1 engine fails, is the hydraulic capability of system A is greatly reduced? How is the gear raised at a normal rate to maintain climb performance?

Answer 3

Yes, raised via the landing gear transfer valve (LGTV)

B fluid transfers to A system to raise the gear (one way only)

Question 4

How can the gear be lowered without hydraulic pressure? Can it be raised without hydraulic pressure? When is the landing gear lever locked? Can it be overridden?

Answer 4

Lowered by manual gear extension - releases uplocks and gravity falls
No, it needs HYD PRESS to be raised.
Landing gear lever is locked on the ground - can be overridden by the lever lock override trigger

Question 5

When must RTO be selected? When is RTO braking available?

Answer 5

Selected prior to Takeoff when:
-Aircraft on the ground
-Antiskid and Autobrake systems operational
-Wheel speed less than 60kts
-Forward Thrust Levers positioned to IDLE
RTO braking is available:
after reaching a wheel speed of 90kts when the Forward Thrust Levers are retarded to IDLE

Question 6

What could cause the ANTISKID INOP (amber) light to illuminate?

Answer 6

Fault in anti skid monitoring system or parking brake system

Question 7

What do the red and green position lights on the forward landing gear panel indicate?

Answer 7

RED = gear unsafe or disagree (in transit) 
GREEN = down and locked

Question 8

What is the purpose of the aft overhead panel Supplemental Landing Gear indicator lights?

Answer 8

Uses another prox switch to indicate gear is down and locked (secondary indication)

Question 9

Is the Alternate Brake system capable of applying auto brakes?

Answer 9

NO (anti skid is still available)

Question 10

What protects the aircraft from loose tread or foreign object debris in the main wheel well during landing gear retraction?

Answer 10

Frangible Fitting Valve (when impacted relieves hyd pressure and drops the gear)

Question 11

How is nose wheel steering powered?

Answer 11

Powered when the nose gear is down position and compressed by weight of A/C

Hydraulic System A: Normal mode
Hydraulic System B: Alternate mode

Nose Wheel Steering Switch controls the LGTU

Question 12

If normal and alternate brake pressure is lost, how is braking accomplished? Are there any limitations?

Answer 12

Emergency brake accumulator is used.

6 applications allowed, (8 hours parking brake engaged) normal anti skid

Question 13

Describe how tires are protected from explosion during thermal expansion caused by hot brakes?

Answer 13

4 thermal fuse plugs in each main inner wheel. Plugs melts to release tire pressure

Question 14

What does a Parking Brake Warning (red) light indicate?

Answer 14

Parking brake set with adequate hydraulic pressure