Flaps are high-lift devices mounted to the rear portion of an aircraft's wing.
- Some types of flaps increase lift by increasing the wing's camber, or, at least, that of its lower surface (plain flaps, split flaps, Junkers flaps).
- Most flaps increase lift by increasing both the wing's area and its camber (Fowler flaps, gouge flaps, Fairey-Youngman flaps, zap flaps).
What would one call a flap that increased the wing's area, but not its camber (like the first stage of a Fowler flap)?