GB886204A - An improved launching or engine-testing platform for vertical take-off jet-propelled aircraft - Google Patents

Abstract

886,204. Vertical take-off aircraft launching platforms. SHORT BROS. & HARLAND Ltd. Aug. 30, 1960 [June 25, 1959], No. 21868/59. Class 4. A platform for use by vertical takeoff aircraft with downwardly directed direct lift engines, comprises a substantially horizontal frame carried on a sub-structure at a height above ground level, the parts of the frame on which the aircraft is to stand having a reticulated material thereacross, the density of which is such as to cause a substantial pressure drop in the gas effluxe stream passing therethrough, the gas stream being conducted away beneath the frame. By this means, recirculation of exhaust gases into the engine air intake, and downward suction effects on the aircraft wings, are avoided. Fig. 1 shows the platform in plan, and Fig. 3 is a partly broken away view in plan of one panel of the platform. In Fig. 3, the substructure comprises spaced parallel channel members 20 resting on pads 21 on the ground, and covered by metal sheeting 201. Above each pad is a pillar 22, the pillars being connected by bracing struts 221. Girders 23 on pillars 22 extend at right angles to members 20, and are overlaid by three grid units 24 (two shown in part). The central panels 28, Fig. 1, have a steel mesh covering, through which the engine exhaust gases may pass. The remaining panels 25, are covered by sheet metal plates 26, Fig. 3. Access to the platform is provided by sloping ramp sections 31, Fig. 1, of which the grid units have no covering, to allow free lateral passage of the exhaust gases from under the platform. Alternatively, the ramp members may be hinged to the platform, and be raised to horizontal positions flush with the platform to allow lateral passage of the gases. To prevent the gases from issuing from the upwind side of the platform vertical sheet metal flaps may be inserted between the platform and the ramp. Where no ramp is used, such flaps may be hinged at their lower edges to the platform, so as to lie flat on the ground when not in use. Pads 30 are mounted on the platform, Fig. 1, being composed of spaced sheet metal plates interleaved with asbestos sheeting, to protect the landing gear tyres from the head of the exhaust gases flowing beneath the platform.