Devices for Modifying Lift & Drag

Question 1

What are the three categories of devices used to modify lift and drag?

Answer 1

Trailing Edge Devices
Leading Edge Devices
Spoilers/Airbrakes

Question 2

What does deploying flap do for lift and drag?

Answer 2

Deploying flaps increases lift but also increases drag.

Question 3

What are some types of trailing edge flap?

Answer 3

Plain Flap
Split Flap
Slotted Flap
Fowler Flap
Slotted Fowler Flap

Question 4

Describe Leading Edge Slots

Answer 4

Leading edge slots are fixed aerodynamic devices on wings that allow some high pressure air from the underside to ‘bleed’ to the upper surface in certain phases of flight, delaying boundary layer separation.

Question 5

Describe Leading Edge Slats

Answer 5

Leading edge slats alter the wing camber and are retractable. They allow some high pressure air from the underside to ‘bleed’ to the upper surface in certain phases of flight, delaying boundary layer separation.

Question 6

What are some advantages of steeper approaches and climbs enabled by flaps?

Answer 6

A steep descent requires less thrust, which reduces noise impact.

A greater angle of climb or descent enables better obstacle clearance.

Question 7

What is the flap limiting speed?

Answer 7

VFE Speed

Question 8

What are some of the effects on aircraft performance of a failure of high-lift devices?

Answer 8

Higher approach speeds
Shallower approach and climb gradient
Longer take-off and landing roll
Less efficient braking
Flap Asymmetry