The post the other day about Martin-Baker ejection seats didn’t go into a lot of detail on alternatives. One such alternative in vogue in the 1960s and 1970s was the crew escape module.
Ejections are hard on the pilot under the very best of circumstances. The accelerations, the wind blast and flailing virtually guarantee at least some injuries to the pilot. The Mach 2 speeds of jets in the 1960s raised the question of how a crew would survive ejection at speed and altitude. Rather than forcing a pilot out of his nice warm (if doomed) cockpit, designers decided to treat the entire cockpit as an escape pod, and slice it from the jet.
As it turned out, ejections at supersonic speeds turned out to be vanishingly rare, and even then, a surprising number of pilots on conventional seats survived. And designing an escape pod for a tactical aircraft forced a lot of penalties upon a plane. First and foremost, any system using a pod was quite a bit heavier than conventional seats. And weight is something any good aircraft designer would sell his mother to reign in. The additional complexity of any pod system (think how hard it becomes to design in all the wiring, hydraulics and avionics and the explosives needed to shear them and the pod in an emergency) meant a lot more design, engineering and testing time had to be front loaded on the introduction of any jet, and the maintenance load increased on the service phase of a jet’s life.
The pod on the F-111 was generally popular, and quite successful. But the penalties and costs were such that few other aircraft have used this approach to crew escape since.