National Audit Office report 20.9.00
"The Sqn Ldr emphasised the frequency and volume of these types of failures both before and after the crash of ZD576. Because they were not well understood by either aircrew or ground crew, and there was then little guidance from the manufacturer, the standard fix for these problems was first to swap the two engine DECUs and if the fault re-occurred to then change the DECU. If the problem continued ground crew would change the Hydromechanical Actuator. The squadron had to change the DECUs so often that they ran out of them. A further problem in understanding and rectifying faults during this period was that the type of faults normally left no trace and were very difficult to replicate on the ground and therefore verify and diagnose. The reverse of this was also true in that some ground checks did not function properly. For example, the overspeed ground check often produced the very fault it was intended to avoid.
The poor serviceability of the aircraft also had a knock on effect on fault reporting. A tendency developed unofficially amongst crews but which was strongly supported by squadron executives to not formally report all faults because squadrons stood to lose one of their few, or their only, remaining serviceable aircraft and thus be unable to fly and meet tasks. As a result the Sqn Ldr considered that formal fault records that the Department have presented to demonstrate the relative good serviceability of the Mk2 as it entered service would significantly understate the true position."
What the witness did not know (I've spoken to him) was that funding had been slashed for Fault Reporting by the RAF Chief Engineer. (CHART confirms a 25% overall cut in 1992; it was actually 28%, 3 years running). EAs were instructed not to submit requests for investigations, but save them up and submit omnibus requests. This became academic as (a) junior suppliers were permitted to over-rule senior engineers within AMSO/AML and prevent requests being approved, and (b) funding was chopped to the extent even safety related investigations were refused.
When you put both these issues together (Sqns and EAs not reporting and funding being stopped), it places the criticism of the aircrew and ground crew (for not reporting faults) in a completely different light. The Chief Engineer would have known of this, and certainly his 2 i/c did (Director General Support Management, an Air Vice Marshal) because the latter threatened his staffs with dismissal in December 1992 for drawing attention to the gross, systemic failures being encouraged and perpetrated in the Chief Engineer's name. This, during the so-called "Golden" age of airworthiness.
