USAAF flight jackets
The USAC / USAAF used 3 types of parachutes: backpack type, chest type and seat type parachute.
All these types were designed for different purposes. Bomber crew members needed to move freely in the aircraft so they had to wear a chest type harness. In case of a bail out, they simply clipped the chest parachute onto their harness by means of rings and hooks.
On the other side, bomber pilots used the backtype parachute. This means they had the parachute always on their backs, they couldn't take it off.
Most fighter pilots wore a seat type parachute. This is basically a harness with a parachute pack fixed at the pilots buttocks. The parachute pack fitted into the hollow aircraft pilots seat. A cushion was added to improve the pilots comfort as the parachute pack is quite hard to sit on.
Chest type parachute
Left: Front view of a "yellow group" A-4 chest type group made by American Lady Corset Co, 1944.
Middle left: Side view of the A-4 group, the hooks are on the harness and the rings on the parachute pack.
Middle right: Close up of the harness closing system and hooks. The A-4 assembly was very similar to the RAF observer harness.
Right: Back view of the backpad.
Seat type parachutes
Left: Front view of a S-2 seat type assembly made by the Irvin Air Chute Co, 1943 dated.
Middle left: Side view with parachute pack and additional cushion in place.
Middle right: Another side view, note the rip cord.
Right: Close up of the parachute pack.