GB379489A - Method of and means for verifying on the ground, the force conditions for the safe taking off of aeroplanes - Google Patents

Abstract

379,489. Dynamometers. TECALEMIT, Ltd., Great West Road, Brentford, Middlesex.-(Piquerez, E. ; 4, Avenue de 1a Pommeraie, St.-Cloud, Seine-et-Oise, France.) July 31, 1931, No. 21922. [Class 106 (ii).] For verifying on the ground the forces relating to the flying-off conditions of an aeroplane means are provided for measuring the ratio of the force driving the machine forward to the weight of the machine so that the latter is not allowed to start unless this relation is at least equal to a predetermined safe value. In the diagram the machine is supported by the landing chassis resting on a carriage 1 and the tail skid on a carriage 2 and secured by chocks 7, each carriage being mounted on four rollers running on like curved surfaces of increasing curvature in the direction of motion. On starting the propeller, the carriages ride up the inclines 4 until the reactions of the inclines balance the thrust of the propeller. The tangent of the angle Q then gives the relation between the horizontal thrust T and the total weight P of the machine. In the practical form of the apparatus each landing wheel and the tail skid rests on a small trolley adapted to run on curved inclines located in a pit so that the trolley platforms are approximately level with the ground. A scale may be provided on the edge of the pit to co-operate with a pointer on the trolley. For distant reading ropes attached to two trolleys are led to two spring drums in an instrument let into the ground the movement of the drums causing pointers to move over a scale. This instrument may be provided with printing means to print the value of the ratio on a card which is issued. In addition, a semaphore signal may be provided the arm of which when set stands up but when a catch connected to a trolley is released falls out of sight thus signalling to the pilot that the desired ratio has been reached.