Much is made of the airworthiness issues in this thread, and of course they are worth pursuing, but at the end of the day two chaps were strapped into this beast and bear the responsibility for the end result.
To paraphrase previous posts, for the chaps to be strapped in, the aircraft had to be declared airworthy in the first place. If it was not airworthy, then how on earth can the pilots be deemed wholly responsible for the end result?
This line of argument, like Mr Purdey's, seems to assume that airworthiness, or parts thereof, are optional. Is there no understanding that airworthiness facilitates serviceability and fitness for purpose, as you always need a stable baseline from which to form judgements? In the case of the Mk2 this baseline was a statement by Boscombe Down that the aircraft was not airworthy, accompanied by a raft of valid reasons supported by top level policy statements.
It is facile to say the pilots are ultimately responsible for airworthiness of their aircraft. The decision to fly was based on a false premise. That is, the RTS gave RAF users the false impression the regulations had been implemented properly. At a working level, the decision may be taken to fly with acceptable faults. But the baseline for this decision is the statement (through the RTS) that the aircraft is airworthy at a known build standard and that (ZD576) was at that build standard, or deviations from it were known and the effect understood. Pilots place an enormous trust in their masters to get this bit right – failure to do so is to abrogate Duty of Care because it denies the pilots the ability to make an informed decision.
The MoD’s argument is that, even if the aircraft developed a catastrophic fault just before impact, the negligence had been committed beforehand (at WP A acceptance). This establishes their insistence that prior negligence over-rides later acts or events (which I don’t think holds good in law). But they cannot have it both ways. There is clear evidence of previous prior negligence, in that ACAS issued an RTS that did not reflect Boscombe’s recommendations, and withheld vital information from aircrew. Had that information been available, perhaps the pilots wouldn’t need to have asked for a Mk1 to be retained; their superiors may have challenged the very existence of a Mk2 in service, never mind in theatre.
In my view, what exonerates the pilots is the failure to disseminate these warnings to aircrew. One of Lord Philip's tasks must be to find out where in the chain of command (and airworthiness chain) this dissemination stopped.