GB979221A - Improvements in and relating to short or vertical take-off aircraft - Google Patents

Abstract

979,221. Aircraft supported on the ground by gaseous cushions. ENGLISH ELECTRIC CO. Ltd. Nov. 17, 1961 [Nov. 18, 1960; Aug. 8, 1961], Nos. 39834/60 and 28683/61. Headings B7G, B7K and B7W. An aircraft has nozzles for producing a gaseous cushion enclosing curtain on its underside, the vertical thrust associated with the nozzles being less than the vehicle weight, and energy-storing means for increasing the height of hover above the maximum steady value. In Fig. 3, a plurality of discrete nozzles 16 are provided in the underside of a fairing 15 of the fuselage, the side nozzles having deflectors 17 for producing a forward or reverse component of thrust. Auxiliary pitch and roll control nozzles 7, 8 and 13 are provided. Full span flaps 11 and full span blowing slots 12 located just above the wing leading edge, can be used for high lift. Cold air may be blown through slots 19 over the main undercarriages 18, to cool them when the cushion is in use. In the case of a delta-wing aircraft, the nozzles may be arranged along the edge of the delta planform. Stored compressed gas may be released through the nozzles 16 to give added initial vertical thrust. For take-off, the nozzles are used so that their jet reaction thrust together with the lift from the enclosed cushion exceeds the aircraft weight, so that the aircraft rises initially to a height above the steady hovering height. During this rise, the aircraft is accelerated by jet propulsion units 14 to a speed at which the aircraft is wingborne, the high lift flaps 11 and slots 12 being used. In Fig. 2, the wing has a central flat-bottomed rhomboidal section 110, and outboard sections 10 (one shown) set at a dihedral. Flaps 111 and slotted flaps 11 are provided. Gas turbines 113 in the nose, and 114 in superposed pairs in the wings, supply compressed air to drive turbines of propulsive ducted fans 112 and curtain forming ducted fans 115, the latter having inlets and outlets which can be faired by louvres in forward flight. The curtain is continuous, but may be open at the front beneath the fuselage. The ducted fans may be shaft driven by engines 113 and 114. The ducted fans 112, Fig. 4, blow air through the slots formed by flaps 11 when lowered, to form a jet flap arrangement. For take-off the ducted fans 115 are spun up at zero pitch, and flaps 11 and 111 are lowered, the latter through, say, one hundred degrees, to assist the fan effluxes to spread and form the required curtain. Fans 115 are then set to a coarse pitch, so that the curtain and cushion are formed, and as in the embodiment of Fig. 3, the aircraft rises to a height of, say, 60 feet, being above that which can be maintained by the curtain and cushion alone. During this rise, the fans 112 are driven, to accelerate the aircraft to wingborne speed. Thereafter, flaps 11 and 111 are raised, and fans 115 shut down and their inlets and outlets faired off. Some of the engines 113 and 114 can also be shut down, the remainder driving fans 112.