CONNAN
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DRDO
It is mandatory for a combat aircraft to demonstrate its spin recovery capability during flight test programme. The purpose of this system is to provide emergency recovery of aircraft from an inadvertent spin in case the aircraft controls are ineffective and are unable to pull it out of spin. The recovery is achieved by deployment of a parachute, which applies an anti-moment force at the rear of the out of control aircraft bringing its nose down further. This brings the aircraft into a controlled stabilized dive and helps it to come out of spin/deep stall. DRDO has developed such parachutes for the flight test of LCA. The test altitude envelope for LCA (9500 kg weight) is 2 km to 12 km. The sequence of operation is as follows:
When a drogue gun is fired, the slug mass of the drogue gun moves rearwards and sequentially deploys the pilot chute at an aircraft wake distance of 23 m. When the pilot chute is stretched, snapping of the weak tie (48 kg) separates the slug mass of the drogue gun along with deployment bag of pilot chute. The chute then inflates and consequently pulls the packed main parachute. As the pilot chute moves rearwards the main parachute deploys sequentially. As soon as the main parachute is stretched, snapping of the weak tie (100 kg) separates the pilot chute and the deployment bag of main parachute. This allows the main parachute to inflate and produce necessary drag force of 32 kN, resulting in a yawing movement of aircraft. It then steepens the flight path angle (a-angle) of the aircraft. The aircraft can then be pulled out of spin by increasing its speed. The total operational time of the system is 3 s. When the aircraft comes out of spin, pilot jettisons the parachute by operating the release mechanism. The system has various redundancy/safety devices. When the release system fails, parachute can be separated through failure of weak link by accelerating the aircraft by 30 per cent. Development work at sub-system level has been successfully completed and final qualification tests are under progress.
It is mandatory for a combat aircraft to demonstrate its spin recovery capability during flight test programme. The purpose of this system is to provide emergency recovery of aircraft from an inadvertent spin in case the aircraft controls are ineffective and are unable to pull it out of spin. The recovery is achieved by deployment of a parachute, which applies an anti-moment force at the rear of the out of control aircraft bringing its nose down further. This brings the aircraft into a controlled stabilized dive and helps it to come out of spin/deep stall. DRDO has developed such parachutes for the flight test of LCA. The test altitude envelope for LCA (9500 kg weight) is 2 km to 12 km. The sequence of operation is as follows:
When a drogue gun is fired, the slug mass of the drogue gun moves rearwards and sequentially deploys the pilot chute at an aircraft wake distance of 23 m. When the pilot chute is stretched, snapping of the weak tie (48 kg) separates the slug mass of the drogue gun along with deployment bag of pilot chute. The chute then inflates and consequently pulls the packed main parachute. As the pilot chute moves rearwards the main parachute deploys sequentially. As soon as the main parachute is stretched, snapping of the weak tie (100 kg) separates the pilot chute and the deployment bag of main parachute. This allows the main parachute to inflate and produce necessary drag force of 32 kN, resulting in a yawing movement of aircraft. It then steepens the flight path angle (a-angle) of the aircraft. The aircraft can then be pulled out of spin by increasing its speed. The total operational time of the system is 3 s. When the aircraft comes out of spin, pilot jettisons the parachute by operating the release mechanism. The system has various redundancy/safety devices. When the release system fails, parachute can be separated through failure of weak link by accelerating the aircraft by 30 per cent. Development work at sub-system level has been successfully completed and final qualification tests are under progress.
