This week, we talk about the scary lifesaver - the ejection seat
What is ejection seat?
The ejection seat is a safety mechanism primarily used in aircraft to save a pilot or a passenger by propelling the seat out of the disabled aircraft.
- An explosive charge or rocket is used to propel the seat to a safe distance and a parachute takes care of the rest of the journey down to the ground.
- Everald Calthorp who earlier had invented parachutes devised an ejection seat that used compressed air.
- Romanian inventor Ananstase Dragomir proposed the modern layout for ejection seats in the late 1920s. The parachuted cell design was tested on 25 August 1929 in Paris and got the design patented.
- The technique used before ejection seat was to simply jump out of the aircraft which in most cases was difficult as it would cause injury and was dangerous.
- As with most of the things, World War II led to the development and perfection of parachutes.
- Heinkel and SAAB developed the ejection seat independently. These early models were compressed air powered seats. Heinkel HE 280, the prototype jet fighter, had an ejection system built into it.
If there arises a scenario where ejection is imminent, the command “eject” is used as an early warning that a possible ejection is coming up in next 30 or so seconds. At the critical moment, the command “bailout” is used and the crew ejects.
- When the pilot activates the ejection system, first the canopy is blown off or opened.
- The pilot and the seat are launched through the opening.
- During ejection, a catapult propels the seat up the rails and then the rocket engine takes over.
- The canopy forms another part of the ejection system. Most of the aircraft are designed in a way where the canopy is blown off the aircraft. In some cases to avoid delay or seat hitting the canopy, a specially designed canopy filled with explosive charges embedded within the acrylic canopy which when initiated, shatters the canopy above and the seat is ejected a few seconds later.
- In some other aircraft without canopy, the seats are ejected through hatches. B-52 bombers had ejection seats that were ejected through the hatches, four in the roof and two on the floor.