I've enhanced, colourised, cropped and enlarged the frames for analysis. The online software used places enhancement/colourising icons on the photo's (unless I've cropped them away):
1. "Three Heads"
2. "Woven Mesh"
6. "Mushroom with a face"
7. "Eagle 1 Light"
8. "Eagle 2 Light"
10. "Plane 1"
11. "Plane 2"
I've added this topic here because my own subjective assessment of what I may be looking at is a (military) helicopter...
1. Three Heads
- this is 4 or 5
heads, silhouetted in the foreground with a bright light source flooding out the exposure. Possibly a search light's beam, or a flare.
2. Woven Mesh
- most likely film emulsion damage, the effect of the film sticking together and being peeled away.
- no idea, it's very angular to be film damage. It's more Ural Snowy Owl flushed out of its (night) time sleep than horn. Possibly the same object as in Image 5, seen from a different rotational position, and overexposed.
- at first I thought this was a parachute unfurling, now I wonder if it's an item of clothing, such as a hat, blown upwards by the wind (or a downdraft).
6. Mushroom with a face
- if I squint I wonder if it's a man/line of men carrying a torch or flare, the light source zig-zagging about as he/they move. How small it is on the exposure would suggest they were some distance away if so.
7. Eagle 1 light
- the clearest photo, and quite obviously a bright lamp of some kind, with a particular shape including squared-off edges. I think this may be a helicopter search light, seen at an angle. The smearing down the lens is probably a snowflake, the camera pointed skyward.
I've looked up Soviet helicopters of that era and the twin rotor Yakovlev Yak-24 appears to have a reflector edge which may create that type of angularity. Also it's a question of how the edge of the bodywork the light is recessed into looks when viewed from an angle, and how that might affect the apparent shape of the light.
8. Eagle 2 light
- the same again, only blurry.
- this appears to be showing crystalised crud on the negative, not a print, see full frame below.
10. Plane 1
- this is either another windblown item, or it's a helicopter, out of focus. I don't think it's a plane.
11. Plane 2
- again, I doubt this is a plane, the Soviets didn't have a swept-back wing design until later MiGs, and Semyon would not have been able to photograph more than a blur at this altitude and speed, so a more static helicopter fits the bill.
The Yakovlev Yak-24 had high canopy windows, the same body shape beneath the cockpit windows, a taller rotor stack as a 'tail', the pointed bit on top of that possibly a rotor axle, the shorter front rotor stack behind the cockpit canopy, and the angled tail fins which have a vertical plate at the end, and that round black feature behind the canopy might correspond to the round (radar dome?) on the Yakovlev Yak-24. This exposure would require a light source underneath.
I'm not entering here into what complex involvement the military may or may not have had with the hikers, but it seems likely to me from Semyon's photo's, from his mystery camera, that there was at least some contact, that the military knew they were there and had checked them out from the air in the same way a police helicopter might today.
It may be that they were looking for someone else, and if so would probably return to the area later in daylight and would then see 3 of the hikers laid out on the pass, land, turn them over to check, and that then explains the bodies being moved, the subsequent snow then covering all tracks, and the bodies.
The search lights may even explain the numerous witness sightings of orange orbs, if the effect of the night/distance/weather conspired to change the perceived colour.
Helicopter search lights during rescue mission (colourised)