<div class="section abstract"><div class="htmlview paragraph">THE performance characteristics of various devices applicable for jet directional control, lift augmentation, and VTOL-STOL studied at the NACA Lewis Laboratory are discussed, including jet deflection devices applicable to the conventonal round nozzle and novel nozzle configurations.</div><div class="htmlview paragraph">The results indicate that many of the deflection devices applicable to conventional nozzles can readily be used for directional control or lift augmentation. Other deflection devices, such as movable plug, internal flap, cylindrical thrust reverser, swiveled primary with fixed shroud, and 90 deg side-bleed nozzle, are limited in application to jet directional control or aircraft trim because the loss in axial thrust for a given deflection force is prohibitive or the maximum deflected force obtainable is limited.</div><div class="htmlview paragraph">The novel configurations studied consisted of an annular nozzle with the jet directed perpendicularly to the ground and a Coanda nozzle which deflects the jet over a surface attached to the nozzle.</div><div class="htmlview paragraph">Many of the directional control and lift augmentation devices for use with conventional nozzles can be applied directly to existing aircraft. The more bizarre deflection devices (annular and Coanda nozzles) will require novel air craft configurations in order to realize optimum performance.</div></div>