11.1 High Lift Devices Flashcards
What are slots
Fixed convergent ducts on the leading edge of the wing
How do slots work
Accelerate high pressure air from under the wing and re energise boundary layer to prevent separation of air
What do slots do to aircarft performance
Allow aircraft to fly at slower speeds and fly at higher AOA. Also produce high amount of drag
What are slats
Retractable flight surfaces that move on the leading edge of the wing
What do slats do
Produced convergent slot and increase camber of the wing, allowing high pressure air from from below to re energise boundary layer
What do slats do to flight performance
Prolongs lift which subsequently delays stall at high AOA
What are flaps
Secondary flight controls that increase lift production and low speeds
What negative effect do flaps have
High drag
How much extra lift does a plain flap produce
50-55%
How much extra lift does a split flap produce
60-65%
What is a split flap
Flap with a gap in between two parts which increases camber, causes more drag than a plain flap
What is a slotted flap
Flap with slot which allows air to re energise boundary layer. Also increases camber of wing
How much does slotted flaps increase lift by
65-70%
What is a fowler flap
Split flap that when deployed increases lift by up to 95%
What does a slotted fowler flap do
Create a gap between trailing edge of wing and leading edge of flap and re energise boundary layer giving more lift and lower drag
