Wind-tunnel research comparing lateral control devices, particularly at high angles of attack II : slotted ailerons and frise ailerons

Three model wings, two with typical slotted ailerons and one with typical frise ailerons, have been tested as part of a general investigation on lateral control devices with particular reference to their effectiveness at high angles of attack, in the 7 by 10 foot wind tunnel of the National Advisory Committee for Aeronautics. Force tests, free-autorotation tests, and forced-rotation tests were made which show the effect of the various ailerons on the general performance of the wing, on the lateral controllability, and on the lateral stability, in general, rolling control at 20 degree angle of attack to plain ailerons of the same size. The adverse yawing moments obtained with the slotted and frise ailerons were, in most cases, slightly smaller than those obtained with plain ailerons of the same size and deflection. However, this improvement was small as compared to the improvement obtainable by the use of suitable differential movements with any of the ailerons, including the plain.