Since man's first flight, methods of safe escape from an aircraft which was no longer safe to fly, was paramount. Early escape was provided by a recovery parachute only. As aircraft performance rapidly increased, it became necessary to assist the crewmen in gaining clear and safe separation from the aircraft. This was provided by a propellant driven catapult, which propelled a cockpit ejection seat safely into the sky, with an attached chute to safely lower said occupant to the earth's surface.
The first live ejection took place on a 16 foot vertical ejection test tower using a propellant powered seat. The first live flight test in England occurred on 24 July 1946 when Bernard Lynch ejected from a Meteor III aircraft at 320 mph at 8,000 feet, using a prototype propellant powered Martin-Baker MK I seat. In 1946, Sergeant Larry Lambert ejected from a P61B at 300 mph at 7,800 feet to become the first live inflight US ejection test.
All of these early seats were comprised of a parachute, a seat structure to which the aircrew and parachute were firmly attached, and a propulsive element which forcibly separated the seat and it's passenger from the aircraft. Today's ejection seats are technologically, vastly improved, but remain keyed on the basic structure and premise of the original seat.