Ejection seats have been a regular component of tactical aircraft since the Second World War. Original seats did little more than propel the pilot high enough to clear the tail in a bailout. Later seats added improvements, but still were little more than a blank charge firing the seat up the rails. A great leap in capability came with the introduction of the rocket powered seat, which in addition to the catapult gun used a rocket to add vertical vector to the seat’s trajectory, eventually resulting in the “Zero/Zero” seat that could theoretically safely eject a crewmember from a plane with zero airspeed and zero altitude. But even Zero/Zero seats have limitations. Research, testing, and improved products continue to this day, enlarging the envelope from which aircrew can successfully eject from stricken aircraft. Concurrent with enlarging the successful ejection envelope are developments which seek to minimize the injuries aircrew will sustain in an ejection. For instance, more powerful, longer burning rockets mean a lower initial acceleration vector, which results in fewer spinal injuries. Devices such as restraints to reduce flailing in the windstream also reduce injuries.
Let’s take a look at some of the testing underway for the Martin-Baker seat for the F-35 Joint Strike Fighter.
A successful seat has to get the pilot clear of the airplane and through the canopy. Explosive line charges are used to fracture the canopy. A drogue chute stabilizes the seat, while the seat’s rocket boosts it in altitude. A ballistic charge deploys the main chute. On some seats, airbags are used to provide separation between the seat and the pilot. A new feature on this seat is airbag curtains to stabilize and protect the pilot’s head and neck.
No, no live pilots featured.* Instead, anatomically functional dummies are used. Sharp eyed observers will notice the tests performed at altitude use a Gloster Meteor as the testbed aircraft- a role it has performed almost from its introduction in the mid-1940s.
*In the early days of ejection seats, live test subjects were actually used.