GLIDER GROUND IMPACT TESTS

Abstract

The German Federal Ministry of Transport (BMV) commissioned the Fachhochschule Aachen to investigate the fundamentals of a sailplane parachute recovery system. The pilot uses such a system in case of uncontrollability of the glider. After activation the following sequence starts: a parachute is deployed by a rocket or a mortar and carries the chute bag clear of the tail unit, the parachute inflates and stabilizes the tumbling glider while the pilot remains inside thecockpit. At the end of the recovery procedure the glider crashes on the ground. The fundamentals of this recovery system are presented the references. The most critical situation is the impact on the ground. A series of twenty full scale dynamic drop tests using different types of cockpits were performed at the FH Aachen in cooperation with the German Federal Highway Research lnstitute. The cockpit was manned by a Hybrid L1 Dummy whereby the fuselage was equipped with accelerometers, wing dummies and a stabilizer. The glider was loaded up to a mass of about 350 kg and 527 kg. The test plane was lifted up to a height from which the selected vertical impact velocity of 6 or 8m/s could be reached during free fall. For some tests an additional horizontal velocity of 6 m/s was produced by a slide bar. The pitch attitude angle was varied from 0 to -80 degrees. All tests were filmed by video and highspeed cameras and datas of 37 sensors were processed on-line by computer.