An air pressure relief valve for airbags is described that has high frequency response owing to its low inertial mass. It is able to open to expose up to 2 square feet of exhaust area within .010 second, thus achieving optimum energy management. The relief valve operation is passive; it is opened and closed by variation of air pressure within the airbag, rather than any external power source. The valve may be easily preset to open at any relief pressure in the range of 3 to 7 psig. Also described are two optional control systems that may be used in conjunction with the valve to reduce the tendency of air-dropped cargo pallets to roll over. The control systems employ sensors to detect the velocity and attitude of the pallet, microprocessor logic to make decisions about real-time corrections to air pressure within one or more airbags, and output devices. Users of supplies dropped by parachute: smoke-jumpers battling forest fires; rescue workers; explorers and developers of remote geographic areas (e.g. oil). Pressure management of automotive passenger airbags. Pressure relief for closed environments such as clean rooms or chemical/biological/nuclear laboratories. Explosions within those closed volumes may need to be vented followed by resealing to prevent escape of dangerous materials.