GB563433A - Improvements in or relating to air brakes for aircraft - Google Patents

Abstract

563,433. Controlling aircraft. FAIREY AVIATION CO., Ltd., and YOUNGMAN, R. T. Dec. 21, 1942, No. 18119. [Class 4] An aircraft having an auxiliary aerofoil which can be lowered from a recess in the underside of the rear part of a main wing to a position below the wing is provided with an airbrake such as described in Specification 562,365 and comprising a flap projected into or withdrawn from the airstream by a bellows device communicating with the throat of a venturi tube which is provided with a butterfly shutter. Brake flaps a, d actuated by bellows b, e are provided on the upper surface of the rear part c of the wing and on the under surface of the auxiliary aerofoil f. The bellows communicate by passages m, q with the venturi tube h formed in the wing and provided with a scoop j and a butterfly shutter k closing of which effects inflation of the bellows to render the flaps operative as shown. The shutter may be arranged to be opened consequent upon the lowering of the aerofoil f so that the bellows b is then deflated by suction in the venturi tube and as the passage q is disconnected from the tube, the bellows e is also deflated. The shutter is preferably not closed by the raising of the aerofoil f, independent means being provided for opening and closing the shutter when the aerofoil is in this position. To ensure suction in the throat of the venturi tube when the aerofoil f is lowered, the duct n leading from the passage q to the tube may be convergent as shown or a valve by which this duct is closed when the aerofoil is lowered may be provided. Means such as described in Specification 562,371 may be provided to,ensure that the flaps a, d are brought into operation simultaneously. The mechanism for lowering the aerofoil f may be of the type described in Specifications 461,157, 467,465 and 493,391.