GB713525A - Improvements in high speed aircraft - Google Patents

Abstract

713,525. Controlling aircraft. BAYNES, L. E., and MUNTZ & CO., Ltd., A. Jan. 31. 1952 [Feb. 12, 1951], No. 3407/51. Addition to 664,058. Class 4. An aircraft has a fuselage, two wings hinged to the fuselage about axes which are approximately vertical when the aircraft is in level flight, two tail surfaces set at a substantial dihedral angle (exceeding 20 degrees) and hinged to the fuselage about axes approximately normal (i.e. differing by less than 10 degrees from the normal) to the tail surfaces and control means operable while the aircraft is in flight for varying the sweepback of the wings and tail surfaces, the sweepback of the tail surfaces being variable in unison for longitudinal control and differentially for control in yaw. The wings 2 are mounted on the fuselage 1 by pivots 4 which are substantially vertical when the aircraft is in level flight though the axes of the pivots may be slightly inclined with respect to vertical planes so that the incidence of the wings may vary with variations of sweepback. In the low speed spread position each wing leading edge 12 is swept back with respect to the normal 13 by 15 degrees and the angle of incidence is 6 degrees and in the high speed position it is swept back by 60 degrees and the angle of incidence is 1“ degrees. For longitudinal control the wings are adjustable in unison between these extreme positions and for lateral control they may be moved differentially through Œ 10 degrees for low speed flight and Œ 5 degrees for high speed flight. The tail surfaces 15 have a dihedral angle of 32¢ degrees and they are each adjustable about an axis 18 inclined by 7 degrees to a normal 19 to the plane of the surface and by 5¢ degrees to a normal to the direction of flight in order to vary the incidence with variation of sweepback. For normal low speed flight the leading edge 22 of each tail surface is swept back by 15 degrees to a normal 23 to the direction of flight and the angle of incidence is 3 degrees. For high speed flight the sweepback is 45 degrees and the angle of incidence zero. For longitudinal control the tail surfaces 15 are movable in unison with the wings forward by 5 degrees and backward to the fully swept position and for directional control they are movable differentially Œ20 degrees for low speed flight and Œ 5 degrees for high speed flight, all angles being measured in the planes of the tail surfaces. The surfaces are adjusted by means of screw and nut mechanisms controlled by actuators coupled to the rudder bar and control column.