The evolution of energy absorption systems for crashworthy helicopter seats

The objective of this paper is to trace the development history of the energy absorbing systems used on crashworthy helicopter seats from their beginnings in the early 1960s to the current time. Its purpose is to assess the state-of-the-art of these systems and to prescribe the path of future needs and efforts. This paper emphasizes the evolution of energy absorption systems. It summarizes early investigatory and developmental concepts, as well as the evolutionary process that led to the systems that are being produced and fielded in today's helicopters. It discusses the many different kinds of energy absorbing concepts that have been suggested, developed, and fielded by several different seat suppliers located around the world. It also discusses the approaches used to satisfy the many different requirements, military, armored and unarmored, as well as civil. It discusses advanced concepts as well as work that remains to be done to provide the best possible crash protection to occupants of current and future helicopters.