Chapter 17 Lift Augmentation

Question 1

What are the benefits of trailing edge flaps?

Answer 1

They reduce the landing and take off length.
They can improve the pilots view of the runway on decent as the pilot doesn’t need a high AOA.
They can be used for steeper decent angles

Question 2

What does a plane flap do?

Answer 2

Increases CLMAX and reduces the critical angle (The CL Alpha curve moves up an left)

Question 3

What effect does lowing the flaps have on the CP?

Answer 3

Lowering trailing edge flap moves the CP aft. This can produce a nose-down pitching moment but, in practice, other effects usually predominate.

Question 4

What are the names of the different trailing edge flaps?

Answer 4

Plane
Split
Slotted
Flower flap

Question 5

What effects do slots have on the boundary layer

Answer 5

Flow separation is delayed and occurs at a greater critical angle
Provide a higher CL MAX
Stall speed is decreased

Question 6

What are the different types of leading edge devices

Answer 6

Slat
Variable camber
Krueger

Question 7

What is deployed first and retracted last

Answer 7

Leading edge devices as they are more effective than trailing edge devices

Question 8

What percentage of flaps is just drag? And when would you use it

Answer 8

The last 50%
You would use them on decent to slow the aircraft as it is all drag in the last 50%

Question 9

What would happen if the right side of the flaps extended on the aircraft and the left didn’t?

Answer 9

The right wing has more flap the arc will roll left and yaw right

Question 10

Flap-setting errors, such as mis-selection and premature/late extension or retraction of flaps will result in

Answer 10

Increased take-off and landing distances and speeds.
Reduced climb performance and shallower descents.
Dangerously reduced margin above the stall.

Question 11

Why would you use flaps on take off?

Answer 11

Allows for a shorter runway distance.
Once airborne the aircraft is better of in a clean config.
Must be climbing and accelerating before the flaps are retracted to prevent a stall.

Question 12

What would happen if the flaps got stuck extended?

Answer 12

Increased fuel burn
Limited speed
Increased drag
Reduced climb performance
Lower ceiling
Reduced L/D ratio

Question 13

What happens if the flaps wont extend?

Answer 13

Longer landing distrance
Worse view of the runway on decent