Wind-tunnel Investigation of Split Trailing-edge Lift and Trim Flaps on a Tapered Wing with 23 Degree Sweepback

Note presenting the results of force tests and pressure-distribution measurements from a wind-tunnel investigation to determine the effects of size and hinge location of lift and trim flaps on the lift and pitching moment characteristics of a semispan tapered wing with 23 degrees sweepback of the quarter-chord line. The flaps were tested with different chords, spans, and trim flaps. The results indicated that the static longitudinal stability of the sweptback wing, as indicated by the slope of the curves of pitching-moment coefficient against lift coefficient, was increased when the lift flaps were deflected, especially for the larger flaps.