TWO-STAGE ENERGY ABSORBING SYSTEM FOR ROTARY-WING AIRCRAFT SEATS

A seat and an energy absorbing system for a seat including sequentially activated first and second energy absorbing devices. The first device is resiliently deformable and activates to accommodate less severe dynamic events whereas the second device plastically deforms to accommodate severe dynamic events such as a crash. In use, when a first predetermined load value is exceeded the first device activates until a compressive limit of the first device is reached, after which exceeding a second predetermined load value transfers remaining energy to the second device. In embodiments, the first device operates to permit a limited amount of seat bucket stroking followed by recovery to an original state, and the second device operates to permit continued stroking without recovery to an original state.