Definition
A flap setting in which the wing flaps are extended to their maximum deflection, producing the greatest increase in lift and drag available from the flap system. Used primarily in the landing phase to permit a steeper approach angle and a slower touchdown speed.
Plain English
The flaps are lowered all the way down. This makes the wing produce more lift at slow speeds and adds a lot of drag, which lets the airplane come down at a steeper angle and land more slowly.
Context Anchor
You will hear or use this during landing practice, approach discussions, and instructor questions about aircraft configuration.
Derivation
“Full” means complete or maximum. “Flap” comes from the ordinary idea of a movable piece; on an airplane, flaps are movable panels on the wing. Together, “full flap” means the flaps are moved to their maximum allowed setting.
Why Pilots Care
It permits slower approach speeds and shorter landing distances but increases drag and requires careful speed and attitude management.
Intuition Check
Full flap does not mean “extra safe” or “best for every situation.” It means the maximum flap setting is selected, and that setting must fit the airplane, speed, and situation.
Example Sentence 1
On final approach to the short grass strip, she selected full flap to steepen the descent and slow the airplane for touchdown.
Example Sentence 2
Strong crosswinds may make full flap undesirable because it reduces aileron effectiveness.