An Energy-Absorbing Seat Design for Light Aircraft

Aircraft seats that merely hold the occupants rigidly in place have been satisfactory when considering horizontal or lateral decelerations; but they have not proved sufficient when accidents occur resulting in large vertical deceleration. This deficiency led to the concept of an energy-absorbing seat, which would utilize the space between the seat bottom and the floor to absorb impact energy and reduce accelerations, thereby increasing occupant survival potential.

To establish the seat design strength requirements, a maximum tolerable “g” load was chosen, and the maximum vertical velocity was calculated based on the available arresting distance. The effect of varying passenger weight was investigated, and a weight was chosen for design purposes. This then defined the load-deflection requirements of the seat. Other requirements established that weight and cost be kept to a minimum and that conventional materials and fabrication processes be used.

The development and static and dynamic testing leading to the final design of a lightweight, economical, energy-absorbing seat are described.