A seat system has separate air bladders in the seat bottom and seat back. The seat bottom bladder is in fluid communication with the seat back bladder through a plurality of rigid interconnecting tubes, and valves in the tubes or orifice size can control flow rate of air exchange between the seat bottom bladder and the seat back bladder. A panel of resilient, compressible open cell foam extends in each of the seat bottom bladder and the seat back bladder. Through-holes in the foam panel permit accelerated air evacuation to the other bladder when the seat withstands a significant shock event. The vibration and shock attenuation characteristics of the seat are jointly provided by the panel spring force and the bladder air pressure.