I was the FA (Fighter Allocator) at Buchan when actually had an IMC midair!
It was, IIRC, 1988 or 89, and during an exercise. 360 Sqn Canberras were providing jamming targets and one was being intercepted by a Leuchars F-4.
Now, during jamming exercises, such as Coffee C, jammers and fighters are assigned safety height blocks and, when unsure of each others locations, stay inside them. Since this was an exercise none had been promulgated. It was also night and IMC. (I did express my concern about an hour before the accident to the MC and this was recorded for posterity in the subsequent investigation.
Anyway. The F-4 closed on the target, did so too fast, and got a breakaway cross on the radar and duly broke left. They felt a bump and suspected they'd crossed through the Canberra's wake turbulence.
The Canberra felt and impact which rolled them to one side and on recovering found they'd lost their port wing tank. They called a Mayday, said they'd had a midair, asked if the other aircraft was OK, and diverted to Newcastle.
The F-4 on being advised, ambiguously, that the Canberra had a "problem" suspected they'd thrown him around in their wake turbulence. When they were then ordered to RTB they were pissed off and thought they were in for a bollocking. It was only when duty pilot in LU ATC asked if they'd done a low speed handling check and were informed of the state of the Canberra did they realise what had actually happened.
On inspection after landing witness score marks were found on the underside skin of the right wing and the right tail piece, along with damage to the missile rail. The F-4 had broken at 90 degrees and the Canberra wing tank had gone between the F-4's wing tank and missile pylon, rupturing against the bottom of the wing and then the tail.
Both aircraft had been literally thousands of an inch from total destruction.