Definition
Flap positions extended somewhere between fully retracted and fully extended, used to increase lift and drag in measured amounts rather than all at once. Common partial settings include the takeoff position and intermediate approach positions, each providing a specific combination of lift and drag suited to that phase of flight.
Plain English
The flaps can be lowered partway instead of all the way. Pilots use these in-between positions to slow the airplane and steady it during takeoff and approach without committing to full flaps.
Context Anchor
Seen during speed changes, approaches, pattern work, and checklist steps where the pilot selects a specific flap position rather than full flaps.
Derivation
Partial comes from Latin words meaning “part” or “share.” Flap comes from an older English word for something that moves back and forth. Setting means a selected position. Together, the phrase means the flaps are placed at one of the available part-way positions.
Why Pilots Care
They let the pilot change speed or descent rate smoothly without large pitch changes, which is especially useful when flying on instruments.
Intuition Check
Partial does not mean vague or approximate here. It means a specific selected flap position that is less than full flaps.
Example Sentence 1
As she slowed the airplane to approach speed, she selected a partial flap setting to help stabilize the descent.
Example Sentence 2
With partial flap settings in use, the descent rate stabilized without requiring a large nose-down pitch attitude.