GB582206A - Improvements in tailless airplanes - Google Patents

Abstract

582,206. Tailless aircraft. NORTHROP AIRCRAFT, Inc. Jan. 25, 1944, No. 1417. Convention date, Sept. 24, 1942. [Class 4] A tailless aircraft is rendered longitudinally stable by disposing the aerodynamic centre 15 of the wing ahead of the centre of gravity 13 of the machine, and by providing control surfaces having negative trailing characteristics, i.e. surfaces whose angles of attack increase with increase of incidence of the wing. In the arrangement shown in Fig. 5, the control surface 17 is pivoted at 19 so as to be overbalanced, and a balance tab 23 is provided, while in the construction according to Fig. 7 the surface 11 is controlled by a weight 24, or a spring may be used in place of a weight, Fig. 8 (not shown). Alternatively, the control surface may be provided at its leading edge with a vane projecting into a sealed recess at the trailing of the wind, the recess being in communication with selected points on the wing surface, Fig. 6 (not shown), or gyroscopic control mechanism may be used to impart the negative trailing characteristic. The aircraft illustrated in Fig. 9 is provided with control surfaces 27 incorporating balance tabs 29, as in the arrangement according to Fig. 5, and trimming tabs 31, together with rudders 33. The surfaces 27 may be used as combined elevators and ailerons, and as landing flaps. Alternatively, the members 27 may be employed only as elevators and stabilizing flaps, in which case the members 33 serve as ailerons. Instead of employing trimming tabs, a hydraulic or electric booster may be incorporated in the elevator control system, the position of the control column determining the elevator hinge moment. The control forces are applied by movements of the pilot's control member in the conventional directions.