@Spookdaddy might have some good theories and/or knowledge about this.
Not much I'm afraid.
Although I lived bang in the middle of one of the hotspots, I was maybe a bit too young to register any extraneous weirdness among all the general everyday weirdness. Three days weeks, ongoing power cuts, the IRAs first sustained bombing campaign in England; during that period life was odd and stressful all round. Playing snakes and ladders by candlelight with my grandad, home because the power supply to his works was shut off four days a week, while listening to radio reports of bombs going off at Harrod’s and Euston Station - I think if a glowing object had landed in the garden my response would have been: ‘Ooh, look grandad - there's
another thing. Anyway....your throw’.
(We tend to decontextualise with hindsight. Or – at least – we tend to see the elements that create that context as optional add-ons, rather than part of the very fabric of our consciousness at the time. Quite frankly, I think the odd UFO or black helicopter would have provided some light relief.)
Around ten years later, my then girlfriend's dad told me about that period. He'd worked the quarries and had been in precisely the same position as the guard mentioned in David Clarke's report (and maybe even the same place): parked up in the dark in a Landrover, 'guarding' explosive stores with a pickaxe handle.
The quarries were still a bit Wild West back then - even a decade or so later, when I worked summers at Hindlow, some pretty unbelievable stuff went on. As he told it, it had only really just registered with quarry admin (probably as a result of the ‘73 bombing campaign) that explosives might be - you know - something they should maybe keep a bit of an eye on. Up to that point it had all been a bit shoddy and unregulated.
There's another thing which is rarely - if ever - mentioned, but which, at least in relation to the Buxton and Peak District sightings, might be a factor.
Mines Research (more precisely - the Safety in Mines Research Establishment) had a base at Harpur Hill in Buxton, right on the edge of the moors. This became the Health and Safety Laboratory in the 90's. This place is not the walking around in hi-vis with a clipboard type H&S – it’s about blowing shit up, dropping stuff on it, setting fire to it and generally seeing what mayhem you can visit on something before it gives up the ghost. Stuff gets tested up there, and some of that stuff is of a sensitive nature. I have absolutely no evidence that it was – but it really would not surprise me at all if the place might have been used as a base for military or police helicopter trials and testing.
It sounds to me very much like a mix of things going on...
Definitely a case of this, I think.