High Lift Devices Flashcards
What are high lift devices designed to do?
Increase the lift produced by the wing
What are some common high lift devices?
-slots
-slats
-flaps
-leading edge flaps
-flapperons
Are high lift devices primary or secondary flight controls?
Secondary flight control systems
What are slots?
Fixed convergent ducts or gaps
Where are slots typically located?
Located primarily on outboard leading edge but can also be used along whole span
What do slots allow for?
Allows high pressure air from beneath the wing to accelerate through the top of the wing and re-energise the boundary layer
What do slots prevent?
Separation, stagnation & stall
What do slots allow the aircraft to do?
Fly at slower speed at higher angles of attack
Do slots increase lift?
No
What is a disadvantage of slots?
They produce a fair amount of drag
What are slats used for?
They increase loft production at low speeds such as takeoff and landing and can produce significant drag which is useful during takeoff & landing
Are slats movable and can they retract?
Yes and yes
What do slats increase?
Camberwell which increases lift
Due to drag from slats do they delay or advance stall at higher angles of attack?
Delays stall
Name 5 flap types?
-plain
-split
-slot
-fowler
-slotted fowler
What are the two types of leading edge flaps?
Krueger & flaperons
What do heavy aircraft use in conjunction with trailing edge flaps?
Leading edge flaps
What is leading edge droop?
A device on the leading edge of the
What does leading edge droop do?
Improves airflow over wing at high angles of attack
Increases camber which in turn increases lift
Reduces stalling speeds
How do flapperons operate?
Deflect collectively to act as flaps
Deflect differentially to act as ailerons
Do flapperons have combined or separate controls?
Separate
Where are Krueger flaps fitted?
Leading edge of wing
What moment do Krueger flaps produce?
A nose up pitching moment
What makes Krueger flaps different to slats and slots?
It deployment
