There was a significant helo/albert collision during GW1, it happened on the ground when a (Saudi?) Super Puma taxied through the wing of one of hercs whilst it was starting up. As I recall the ALM on the long lead got a free Avtur shower and several feet were trimmed off the starboard wing. I think that the frame was later recovered to Lyneham by a STANEVAL/Test crew who had been issued with a large bag of brave pills.