A COMPARATIVE EVALUANON OF GLIDER PARACHUTE RESCUE SYSTEM DESIGN ASPECTS

Abstract

Emergency escape from gliders has traditionally involved personal parachutes which rely on the pilot effecting a timely exit from the cockpit, and manually releasing his chute when clear of the aircraft. Problems with canopy jettisoning pilot egress from the cockpit and pilot incapacitation warrants the consideration of alternate parachute recovery solutions. Irvin's experience with emergenry escape parachutes and recovery systems for unmanned aircraft has been used to present a comparative evaluation of alternative recovery systems and a trade-off analysis of benefits and disadvantages. Concepts for recovering the whole aircraft, complete with pilot, overcome many problems but introduce others. These include extra weight, the need for reliable and safe deployment systems and the requirement for a crash worthy cockpit and shock attenuation devices to protect the pilot at ground impact. In contrast to personal parachutes, such an integral recovery system needs an airframe specifically designed to provide suitable anchor points, load paths and resistance to opening shocks. In consequence it becomes subject to scrutiny against airworthiness standards by the relevant governing body so that retrofitting such a system to an existing airframe is likely to be problematic. These factors, together with their likely impact on cost and safety considerations, are discussed. A preferred system concept uses a drogue parachute to stabilize the stricken glider and auto-extract the pilot who then returns to earth via a conventional personal parachute.