If I may just add something on the issue of cost. Doing the job correctly in the first place is invariably cheaper and better in the long run.
The example I always use involved multiple fatalities in 2003. The mandated regulations were ignored and an unsafe design was installed. Boscombe refused to issue MAR recommendations but the 2 Star ruled that (any) aircraft need not be functionally safe. The correct design in one aircraft had been costed at a mere £50k. Correcting the unsafe design cost £4.4M and lost the programme 5 months (which was recovered as the TI didn't have any faults during trials). But the other aircraft was not corrected, and two died. Not counting the tragic loss of aircrew, this single event cost MoD around £60M (not sure of cost of the aircraft, and accept that cost is sunk anyway). The same applied to Nimrod - just add another few zeroes. And Chinook Mk3, around £300M. Please don't mention cost and alleged unaffordability. There's a reason why we don't have the money and it's nothing to do with budget cuts. It is all about not implementing the same regulations and systematically and quite consciously wasting money.