Landing Gear

Question 1

Give the 5 main landing gear arrangements.

Answer 1

Bicycle, tail dragger, tricycle, single main gear, quadricycle gear

Question 2

Discuss a bicycle gear config

Answer 2

• Used mainly on slim fuselages and large wingspans
• c.g should be aft of midpoint
• Aircraft must takeoff and land in a flat attitude.

Question 3

Discuss a tail dragger gear config

Answer 3

• More prop clearance
• Less drag and weight
• Poor forward visibility
• Risk of nose over

Question 4

Discuss a tricycle gear config

Answer 4

• Better forwards visibility.
• Length must be set so tail or wings don’t hit the ground.
• Optimum range of aircraft’s weight carried by nose wheel is 8-15%.
• Trade-off between steering and lifting the nose during take-off.

Question 5

When is a single main gear used?

Answer 5

Gliders for simplicity

Question 6

Discuss quadricycle gear

Answer 6

• Requires flat takeoff and landing attitude
• Enables a cargo floor very low to the ground.

Question 7

Why are there alpha and beta angles for nose gear?

Answer 7

To avoid FOD entering engines.

Question 8

Describe the workings of a oleo shock absorber.

Answer 8

Oil-air shock absorber combines spring effect of compressed gas and damping effect of oil.

Question 9

Give three shock absorber types and briefly describe.

Answer 9

Shock strut (absorber is in the strut)

Triangulated (reduces shock absorber deflection but scrubbing effect on wheel)

Trailing link (large gear travel and easy to replace without removing wheel/brake)

Question 10

Give some gear retraction configs

Answer 10

In wing, wing podded, in fuselage, fuselage podded, wing box, in nacelle.