Propellant Actuated Device for Parachute Deployment during Seat Ejection for an Aircraft Application

Propellant Actuated Devices (PAD) are installed on various combat aircraft of Air Force and Naval bases to perform extremely important operations such as parachute deployment, harness and leg restrain, cable cutting, pullers, seat ejection, bomb release or fuel tanks etc. They are basically called as gas generators. Such devices produce the high temperature and pressure combustion gases on initiation and used to perform different operations. These cartridges are single-shot operating devices. The performance of such kind of PADs cannot be tested by non-destructive techniques. Hence, cartridges are designed to function with high reliability and stringent quality control checks at all levels during entire development cycle. The safety features required during handling, storage and transportation are built in the design of PAD. The cartridges are required to undergo different exhaustive design qualification tests to qualify design aspects. Total life of 6 years is assigned to cartridge after performance degradation study of the propellant which includes 2 years installed life. This paper explains about the development aspects of PAD, its use, function, testing and performance evaluation methodology in a suitable fabricated Velocity Test Rig (VTR). The maximum slug velocity is 121.14 m/s in hot condition and minimum slug velocity is 99.14 m/s in cold condition. The main objective of this paper is to device a novel method to measure actual slug velocity of the aircraft gun inside a cartridge using VTR and Doppler RADAR.