the Mull accident is relatively unremarkable save for the appalling loss of life.
The single most important fact reiterated by Lord Philip was that the Controller Aircraft Release (signed by Sir Donald Spiers) was mandated upon Assistant Chief of the Air Staff (AVM Anthony Bagnall).
The CAR stated the aircraft (Chinook HC Mk2) is NOT airworthy and CANNOT be released to service. The primary reasons are (a) FADEC is not permitted in the aircraft (b) the entire Comms and Nav systems are NOT to be relied upon in any way whatsoever. The Comms bit was actually largely irrelevant, because the Intercom was NOT cleared to be fitted to the aircraft. I'm not a pilot, but I suspect this would prevent the aircraft taking off.
Despite this, and the legal obligation he was under, ACAS withheld this rather "remarkable" information from the rest of the RAF and signed to say the aircraft was compliant in every respect. He also withheld, from the BoI, AAIB, Police and all subsequent inquiries that he was sitting on a 1992 report detailing precisely the systemic failings reiterated by Haddon-Cave some 17 years later.
"Unremarkable" is not a word I'd associate with these actions. Criminal, yes. Please don't fall into the MoD trap of only looking at the final act.
Added:
Sorry, I noticed you mention "Icing Clearance" again. What Icing Clearance? A properly amended RTS had no Icing Section in it on 2nd June 1994!! This was an administrative error, but nevertheless it did occur.