The Shackleton falls into the intermediate category of aircraft. The CAA issue was due to the spar booms, as the aircraft were operated well past the initial design life (some 200% past according to one letter by British Aerospace). As such there were doubts over the safety of the aircraft in civilian hands if the level of inspections couldn't be maintained. The only way past this is to have the booms replaced, as was done with the Lancaster in the mid 1990's.
All you chaps that have flown in our aircraft in service - is there any chance we can have details? We're trying to compile a list of where WR963 went over the 37 year career she had.
Kind Regards,
Rich