Originally Posted by
Donkey9871
I seem to recall (having worked in an IPT) that airworthiness documents must be retained for at least 10 years after the out of service date of the equipment. I'd imagine that documentation relating to a crash would fall into that category.
Given that this aircraft was unairworthy, and positively dangerous according to Boscombe Down who grounded their trials aircraft and suggested that the RAF do the same with their (already in service!) fleet, it would seem that different rules apply both then and ever since thanks to the cover up of the improper Release to Service of the Chinook Mk2.