This accident happened many years ago and I'm only posting here in response to a recent e-mail. It was indeed a tragedy.
At the time, what was and wasn't permitted to be flown in a Vulcan relied heavily upon the 'constituted crew' principle. I ask the question, was the crew involved fully constituted or had they been crewed together on an ad hoc basis for the Glenview show? Specifically, why was the Sqn Cdr - the Nav Plotter (who wasn't in the a/c when it crashed) - on that crew for the airshow and were all the other crew members on that day the captain's regular crew members?
We did wonder at the time....