Many of us have watched movies in which a pilot ejects from a crashing fighter aircraft. This is a real ejection seat, although an old one(my guess: late 1960s/early 1970s) and was fitted in the (now defunct) SAAB 37 Viggen.
Mechanism
A charge of gunpowder raised the seat to the edge of the cockpit. There, a motor beneath the seat would ‘ignite’ like a rocket( launching the crew up about 50 metres).
Advantages
These two or more ‘stages’ of charges softened the launch, minimizing the probability of hitting the plane’s edges, and risk to spinal injuries. It also allowed the pilots to eject at lower altitudes but still giving the push required to open parachute. The extension handles are located on both sides of the seat cushion. There are nets for fixing arms and legs so that they do not break when launched at high speed.
Numbers
The pilot could save himself at speeds from 100kmh on the ground to over Mach 1, the speed of sound.
Life is about being kinetic 