Definition
The selected position of the wing flaps for a particular phase of flight, expressed either by degrees of deflection (e.g., 10°, 20°, 40°) or by named detents such as UP, TAKEOFF, APPROACH, or LANDING, as specified in the Airplane Flight Manual or Pilot's Operating Handbook.
Plain English
Where the flaps are set — fully up, partially down, or fully down — for the part of the flight you're about to fly.
Context Anchor
Used in before-takeoff checks, takeoff briefings, landing setup, and rejected takeoff discussions when verifying that the airplane is correctly set before continuing.
Derivation
“Flap” originally referred to something that hangs or moves back and forth, like a loose panel. “Configuration” comes from words meaning an arrangement or shape. Together, “flap configuration” points to the arranged shape of the wing created by the selected flap setting.
Why Pilots Care
The chosen flap setting changes the runway length needed for takeoff and directly affects how much runway remains available during a rejected takeoff.
Intuition Check
Do not read “configuration” here as a vague setup of the whole airplane. In this context, “flap configuration” specifically means the selected flap position and the wing shape that results.
Example Sentence 1
After confirming the flap configuration was set to 10° for takeoff, the pilot advanced the throttle.
Example Sentence 2
During the rejected takeoff the crew left the flap configuration unchanged to keep drag as low as possible.