Glider Rescue Systems

Abstract

Looking at mid-air accidents of gliders the chance of surviving by bailing out and using the conventional emergency parachute turned out to be less than 50%. A glider parachute rescue system can improve this situation. A parachute decelerates the whole glider with the pilot remaining inside the cockpit and lowers glider and pilot to the ground. Most of the mid-air accidents are collisions. Losing parts of the glider structure results in a diving motion and the speed of the glider increases dramatically. Due to the T-shaped tail unit the parachute must be deployed by an active device such as a rocket or a mortar. To obtain longitudinal static stability during the descent, a pitch down attitude angle of about -30 degrees should be kept. The most critical situations appear during the deployment of the parachute and the impact on the ground. In the high speed range the parachute or the riser may collide with the tail unit and this may damage the tail and produces a nose down pitch rotation with a high negative z-acceleration and a negative angle of attack. For avoiding severe injuries during the ground impact a descent rate of not more than 6m/s is necessary. In case of energy-absorbing parts the descent rate may come up to 8m/s. Flight tests for certifying a glider rescue system are only performable in the low speed range. The parachute, the lines, the rocket or the mortar should be tested without a glider.