downsizer
Yes there is an airworthiness issue here:
The inquest heard that the anti-spill valves, which are operated by gravity, had not been checked or maintained for decades and were not listed on the aircraft's maintenance checklist.
Summing up the evidence, the coroner said: "They should have been
part of a risk assessment and appropriate maintenance schedule.
"It was said by the pilot of the Puma that he would have considered the craft to be un-airworthy if he had known that it had an inoperative anti-spill valve.
In order to mitigate the risk of fire and explosion I would imagine that the MOD/RAF quoted the anti-spill valve, so the fact it was inoperative and hadn't been checked for 30 yrs would mean it was not airworthy.IMHO