Definition
A type of wing flap that, when extended, slides rearward on tracks before deflecting downward. This rearward motion increases the effective wing area first, then progressively adds camber as the flap angles down, producing a large gain in lift with relatively little drag at small deflections and substantial drag at full deflection.
Plain English
A flap that first slides backward to make the wing bigger, then tilts down to curve it more. This gives the airplane more lift for slow flight, and at full extension, more drag for landing.
Context Anchor
Seen in discussions of flap design, flap effectiveness, takeoffs, and landings.
Derivation
Named after Harlan D. Fowler, the American engineer who developed and patented the design in the 1920s. Knowing it is a person's name (not a descriptive word) prevents the reader from trying to extract meaning from the word itself.
Why Pilots Care
Fowler flaps give transport and utility aircraft the lift needed for shorter takeoff and landing distances while preserving cruise efficiency when retracted.
Analogy
Think of a Fowler flap like a sliding shelf that first moves out to make the surface larger, then angles down to change how the air flows over it.
Intuition Check
Fowler does not mean a flap setting, such as 10 degrees or 20 degrees. It means a flap design that slides rearward, usually while also lowering.
Example Sentence 1
The airplane's Fowler flaps extended on tracks, increasing wing area before tilting down for landing.
Example Sentence 2
On final approach the aircraft used full Fowler flaps to maintain lift at the low approach speed required for the short runway.