Re: Re Parachutes
"If that stood any chance of being usable"
and thats part of the problem.....it was generally accepted that using it gave little chance of survival. But little was better than none...
For an indication of how high a chance there was of survival, check out the rate of survival of back-seat crew from crashed V-bombers (only the pilots had ejection seats). Not high.
What you have to remember is those exits were built into the four prototypes 002/001/02/01 from the design stage, which were considerably different from the production aircraft. To have fitted the same to the production birds would have required cutting out structural ribs and making a big hole in the fuselage - a significant weakening which probably could not be safely done.
Certainly it couldn't be safely done given the time-scale indicated in the story: in the last episode it had already been established that the aircraft was a leased/borrowed standard commercial aircraft - not the "usual" military jet - as no military aircraft were available due to the emergency. (Kate says that in response to a question from the Doctor). So.....to fit in with the storyline you'd have to draft, plan, design, cut hole, and build in a day or two. Not possible to do safely. Probably not possible to do at all, but certainly not safely.