Maintenance: Landing Gear

Question 1

What does a trunnion do?

Answer 1

Main pivot, attachment point

Question 2

What does an overcenter lock do?

Answer 2

Similar to a knee joint, provides rigidity

Question 3

What are limit switches and what do they do?

Answer 3

They are micro switches that electronically sequence gear retraction

Question 4

What do sequencing valves do?

Answer 4

They are hyd valves that sequence gear retraction

Question 5

What does a red light mean for the landing gear position indicating system?

Answer 5

Unsafe (in transition)

Question 6

What does a green light mean in a landing gear position indicating system?

Answer 6

Down and Locked

Question 7

How many fault free swings must take place during a 100 hr inspection when doing landing gear swings?

Answer 7

5 fault free swings

Question 8

What type of MLG config is this?

Answer 8

Multi-bogey gear

Question 9

Which MLG config is this?

Answer 9

Bicycle landing gear

Question 10

What are the parameters for a bungee chord suspension systems?

Answer 10

Diameter ranges from 1/4 to 13/16”

Shock cord rated from 400-1600 lbs test

Made of natural rubber or synthetic (rubber is reccom.)

Different colours on woven wrapping indicate year/quarter the cord was manufactured

Type 1: shock cord

Type 2: Shelf life of 5 years

Question 11

What restricts the flow of oil, therefore creating a sort of shock absorbtion in an oleo strut?

Answer 11

Tapered metering pin + Restricted orifice

OR

Clack Valve

Question 12

What are the reinstallation procedures for an oleo strut?

Answer 12

• Add oil to level with filler opening, Bleed air out and seal
• Reinstall, repressurize with nitrogen
  
  • Recheck fill after 24 hrs to check for leaks

Question 13

What are the three types of filling valves?

Answer 13

• MS 28889 (most common) -No valve core, 3/4” nut, 5000 psig
• AN 6287 -High press. valve core, 3/4” Swivel is 5/8”, 3000 psig
  
  • AN 812 Older models -Valve core, base nut 5/8”, med press., 1500 psig