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The development of pilot and passenger seats for the GA8 aircraft has provided insight into simplified analysis techniques and empirical approximations that may be applied to aid in the design of low cost seats meeting the requirements of FAR §23.562. The requirements of FAR §23.562 specify dynamic impact tests for aircraft seats together with the limits on occupant injury and seat damage as a consequence of the impact. Among the challenges these requirements provide for design engineers are the difficulties associated with formulating the requirements in the form of traditional strength and stiffness constraints, and that for an efficient design it will likely be necessary to design for loads beyond the linear elastic range of the materials being used. This paper details the lessons learned from a series of dynamic seat tests ultimately leading to the successful demonstration of compliance with FAR §23.562.

The introduction of FAR23.562 to the Federal Aviation Regulations has necessitated the design and testing of aircraft seats with energy absorbing characteristics to minimize pelvic loads experienced when the seat environment is subject to specified acceleration pulses. Aircraft seat designers have applied various techniques to facilitate this energy absorption. Generally these techniques come at the expense of ease of manufacture and durability. This paper describes the development and testing of seating structures fabricated in a simple and easily reproducible form from sheet aluminium. The design employs both compressive buckling and plastic tensile deformation of the aluminium panels in the seat pan as the means of energy absorption. As the post buckled deflections required to provide sufficient seat stroke are large, the design process does not lend itself to simple theoretical analysis.