Take a Seat

It's important for many types of aircraft to have an ejection seat in case the plane is damaged in battle or during testing and the pilot has to bail out to save his or her life. Ejection seats are one of the most complex pieces of equipment on any aircraft, and some consist of thousands of parts. The purpose of the ejection seat is simple: To lift the pilot straight out of the aircraft to a safe distance, then deploy a parachute to allow the pilot to land safely on the ground.


Photo courtesy U.S. Department of Defense
An ejection seat being removed from an F-15C Eagle

To understand how an ejection seat works, you must first be familiar with the basic components in any ejection system. Everything has to perform properly in a split second and in a specific sequence to save a pilot's life. If just one piece of critical equipment malfunctions, it could be fatal.

Ejection seats are placed into the cockpit and usually attach to rails via a set of rollers on the edges of the seat. During an ejection, these rails guide the seat out of the aircraft at a predetermined angle of ascent. Like any seat, the ejection seat's basic anatomy consists of the bucket, back and headrest. Everything else is built around these main components. Here are key devices of an ejection seat:

  • Catapult
  • Rocket
  • Restraints
  • Parachute

In the event of an ejection, the catapult fires the seat up the rails, the rocket fires to propel the seat higher and the parachute opens to allow for a safe landing. In some models, the rocket and catapult are combined into one device. These seats also double as restraint systems for the crewmembers both during an ejection and during normal operation.

Ejection seats are just one part of a larger system called the assisted egress system. "Egress" means "a way out" or "exit." Another part of the overall egress system is the plane's canopy, which has to be jettisoned prior to the ejection seat being launched from the aircraft. Not all planes have canopies. Those that don't will have escape hatches built into the roof of the plane. These hatches blow just before the ejection seat is activated, giving crewmembers an escape portal.


Photo courtesy U.S. Department of Defense
A pilot prepares to pull down the face curtain that will launch the ejection seat up the track of the ejection-seat trainer.

Seats are activated through different methods. Some have pull handles on the sides or in the middle of the seat. Others are activated when a crew member pulls a face curtain down to cover and protect his or her face. In the next section, you will find out what happens once the seat is activated.

Ejection-seat Terms
  • Bucket - This is the lower part of the ejection seat that contains the survival equipment.
  • Canopy - This is the clear cover that encapsulates the cockpit of some planes; it is often seen on military fighter jets.
  • Catapult - Most ejections are initiated with this ballistic cartridge.
  • Drogue parachute - This small parachute is deployed prior to the main parachute; it designed to slow the ejection seat after exiting the aircraft. A drogue parachute in an ACES II ejection seat has a 5-foot (1.5-m) diameter. Others may be less than 2 feet (0.6 m) in diameter.
  • Egress system - This refers to the entire ejection system, including seat ejection, canopy jettisoning and emergency life-support equipment.
  • Environmental sensor - This is an electronic device that tracks the airspeed and altitude of the seat.
  • Face curtain - Attached to the top of some seats, pilots pull this curtain down to cover his or her face from debris. This curtain also holds the pilot's head still during ejection.
  • Recovery sequencer - This is the electronic device that controls the sequence of events during ejection.
  • Rocket catapult - This is a combination of a ballistic catapult and an underseat rocket unit.
  • Underseat rocket - Some seats have a rocket attached underneath to provide additional lift after the catapult lifts the crewmember out of the cockpit.
  • Vernier rocket - Attached to a gyroscope, this rocket is mounted to the bottom of the seat and controls the seat's pitch.
  • Zero-zero ejection - This is an ejection on the ground when the aircraft is at zero altitude and zero airspeed.
Source: The Ejection Site