Wader 2
I agree.
But I must say I’m impressed that the MoD could actually produce such statistics, given that the funding necessary to collect, collate, analyse and report was largely pulled from 1991-93, and never resurrected. I’m not saying it wasn’t done thereafter, but it became optional. You’d be unlikely to have similar detail for most avionics. And it certainly wouldn’t be accurate, or have been subjected to a thorough engineering appraisal.
The very existence of the data may indicate concern over the failure rate. A fuel system failure every 12 flying hours (regardless of their definition which, if anything, is likely to tend to make reliability look good) would, in my experience, lead to Engineering Authorities and MoD Technical Agencies begging, stealing or borrowing money to investigate potential safety problems VERY URGENTLY. (Bearing in mind that money to investigate safety problems was also slashed at the same time. I do not mind admitting that I lied through my back teeth on many an occasion to acquire or re-direct funding to investigate safety issues I’d been instructed to ignore).
Assuming such investigations and subsequent product improvement (modifications , changes, SEMs etc) took place, it would be reasonable to assume they were “firefighting” just to keep the failure rate stable over that period. I know nothing of Nimrod (MR) support, so am willing to be put right. But it emphasises your last point that accurate information is required, which requires a properly phrased question.