Last month BBC R4's Today programme
and Computer Weekly quoted from an MoD memo
that said there was a "positively dangerous" flaw in the Chinook Mk2's safety-critical "Fadec" software.
Software code containing that dangerous flaw was fitted on the type of Chinook that crashed on the Mull of Kintyre in June 1994. The crash of Chinook ZD576 was one of the worst RAF accidents in peacetime.
All on board were killed including 25 VIPs.
There's active discussion today
of a crash 16 years ago because two dead pilots were found to have caused the crash of an aircraft that some inside the RAF and the MoD considered was not safe to fly. The development of the Chinook Mk2 fuel-control software has been one of the most improvised projects we have investigated in decades.
It's likely that two RAF air marshals were unaware of the potential seriousness of the faults in the Chinook Mk2 when they found the dead pilots of Chinook ZD576, Flight Lieutenants Richard Cook and Jonathan Tapper, grossly negligent.
Only after an RAF Board of Inquiry into the Mull crash did it become clear that a series of internal documents had tried to alert the MoD hierarchy to the danger posed by the Chinook Mk2's safety-critical Fadec fuel control system
That those internal MoD memos were not shown to the RAF Board of Inquiry into the Mull crash, or to the Air Accidents Investigation Branch which wrote a technical report on what it found in the wreckage, has never been explained.
The number of those who are now convinced the Mk2 Chinook helicopter was not airworthy
has much increased since the disclosure of these documents.We have published several of the documents
Now we're publishing (below) in technical detail another of the leaked documents: one written by EDS - which is now owned by HP. The EDS report explained in detail what was wrong with the Chinook Mk2's software.
EDS had been commissioned by the MoD to examine the Chinook Fadec's 16, 254 lines of software code.
was carried out in July 1993, nearly a year before the crash on the Mull.
EDS found such a density of "category one" anomalies - the most potentially serious flaws - that I find it hard to believe that the RAF put the Mk2 Chinook into service without a software rewrite.