Landing Gear Flashcards
How many weight on wheels switches are there and where are they?
5 total
2 each main gear
1 on nose wheel.
How is the main landing gear mounted?
A trailing link
How many WOW signals does it take to release the air ground signal output?
3 signals
If one WOW signal is invalid how many have to agree before the air ground output will be released?
2
If 2 WOW signals are invalid how many will be processed?
2
How many proximity switches are there? And where are they located?
19 total 5 WOW - 2 each main 1 nose 12 up and down - 2 per wheel 1 steering - 7 degree limit 1 nose gear doors
Which hydraulic system operates the gear?
1
How are the main gear doors opened and closed?
By a mechanical linkage connected to the main gear.
How are the nose gear doors opened and closed?
Hydraulically at 3000psi.
How is the gear held up?
Mechanical uplock hooks
How many main gear actuators are there and what do they do?
2 one to retract the gear. One to release the over center down lock.
What are the 3 ways to extend the gear?
Landing gear lever
Electric override
Free-fall lever
How is the gear held down?
Through an over center locking mechanism.
What protects the gear from being retracted on the ground?
A lock on the landing gear lever
What are the 3 positions of the override switch and their use?
Normal
Doors - opens nose gear doors
Gear doors - extends gear
How does the free fall lever lower the gear?
A mechanical linkage pulls the up locks open.
How does the override switch extend the gear?
By bypassing the LGEU and sending the the signal directly to the landing gear electro valve.
When does the landing gear warning go off?
Below 1200’ 1 thrust lever below 59 and the other below 45, any flaps setting
- Flaps 0-9 can be cancelled
- Flaps 22-45 can not be cancelled
- Flaps 45
When does the EGPWS give a “too low gear” alert?
Below 500’
Less than 190kts
