Special Weapons Emergency Separation System

Special Weapons Emergency Separation System (SWESS), also known informally as the dead man's switch, was a nuclear bomb release system that Strategic Air Command built into bombers such as the B-52 Stratofortress. The system's purpose was to ensure that an aircraft's payload of nuclear weapons would detonate in the event of the crew becoming debilitated by enemy defences such as missiles. Once armed, the system would ensure that the onboard nuclear weapons detonated if the aircraft dropped below a predetermined altitude.