A Systems Approach to Crash Protection

Crashworthiness is an important driver in the design of military rotorcraft. It is commonly thought that adding improvements in crashworthiness adversely affects other critical aircraft performance capabilities. It can be shown that an integrated systems approach improves the likelihood of satisfying conflicting requirements. Trading the technologies to implement in an integrated approach requires an understanding of the contribution each technology makes to the overall system, as well as the costs (monetary, weight) associated with that technology. Recently, the Army Aviation Applied Technology Directorate (AATD) conducted multiple efforts in the area of improving rotorcraft crashworthiness. These efforts addressed: improving crash protection technologies, developing crashworthiness criteria representative of operational realities, and describing an integrated systems approach to improve the likelihood of protecting crew and occupants in a crash event while simultaneously maintaining mission performance. In an attempt to measure the benefit of a crashworthiness technology to occupant survivability, the Crashworthiness Index (CI) was developed. The CI is a tool to quantitatively assess crash protection technologies. The CI can also be used to assess aircraft configuration crashworthiness as well. This paper outlines how this tool can be used to assess a specific technology's contribution to crash protection and how to trade a technology against other crew, occupant and aircraft protection technologies. This paper also describes how the CI tool allows for design trades to improve crashworthiness capabilities without deleterious effect to other performance capabilities for current and future rotorcraft.