A seat base assembly for a wheelchair includes a dock configured to be mounted to a vehicle frame. An attenuating mechanism is operatively connected to the dock to absorb impact between the vehicle frame and a wheelchair. An interface assembly is operatively connected to the attenuating mechanism to connect a wheelchair to the attenuating mechanism. A crashworthy wheelchair includes a seat having arm rests and a seat back extending therefrom. Front wheels and back wheels are operatively connected to the seat. Each arm rest includes a downward opening slot configured to accommodate a respective one of the back wheels during a negative G event. The wheelchair can include a hook extending down ward from the seat to engage with a respective mating portion of the seat base assembly.