Pobjoy & A and C
Good posts. I would add, however, that when parents encourage their children to fly in MoD gliders, they assume (reasonably) that MoD has complied with regulations mandated upon it. It does not; and that is where acceptabe risk becomes gambling - both on MoD's and the parents part. The trouble is, the latter have nothing to base their decision on, except false assurances by MoD. That MoD permits and encourages these false assurances is the real problem. Mercifully, such contempt for the law is rarer in commercial aviation (notwithstanding recent events) but, as A and C says, parents apply the same standards to both. The risk of anything untoward happening while gliding is indeed low, but parents should be aware that MoD consciously increases the probability of occurrence as a means of saving money. No commercial enterprise, especially in the UK, would (or should) be allowed to get away with that, which is why I agree with the call to hand gliding over to a reputable company.
As many have pointed out, to MoD the re-setting of these assurances is prohibitively expensive, due in part to a poor or non-existent airworthiness audit trail. Yes, with enough money this can be recovered, but it is not a case of issuing a single plan for a fleet. Each aircraft must be addressed separately. The results of the survey must be reconcilable with the accompanying historical documentation. In practice, a 'Beyond Economical Recovery/Repair' price is agreed. As soon as that is reached, a tail number is scrapped. Long ago the RAF decided to stop resourcing the management of this. A figure of £100k per aircraft was mentioned, above. In 1990, avionic LRUs costing more than this were declared 'consumable' and scrapped, simply to avoid the perceived hassle of managing a repair. I recall an RN Board of Inquiry being gobsmacked at this, but it explained why two-thirds of the Sea Harrier fleet didn't have a full nav system.
No contractor would agree to minimum fleet serviceability rate without a caveat saying if the cause of delay was down to historical MoD actions, then there is no liability. Contractors tend not to want to embarrass MoD with this, so there exists a standard 'emergent work' clause that is simply inserted in the contract without comment. This requires MoD to have (a) a resident engineer on site, and (b) he must be intimately familiar with the product. Neither is MoD policy, and hasn't been for over 25 years. The term 'blank cheque' comes to mind.