...PaxBritannica, I was about posting the same pictures (looking noth-north-east). Yes, sadly, it clearly shows where the Ju-52 ended. The 16.50 pictures shows shadow over the area so these two, at 16.40 and 17.00 are the clearest ones. With different infos so far available I agree with some other comments here, it was most probably a stall (left wing) accident. (My personal opinion!)
The distance between the mountain ridges is about 900m. In the left ridge we have the Martinsloch (round opening in the mountain). According to other info, ISA was around 17 degree over standard atmosphere. The wind (max almost 20 knots according other info) was from the north (from behind the ridge on the left side).
Now we have to options:
-1) the pilots on the way home, heading north, wanted to fly straight over the ridge (at the lowest point) , but realized that the performance was not good enough, so they were forced to turn back to the south...
or:
-2) the pilots first wanted to show the Martinsloch, flying north-north-east along the right mountainslope followed by a left turn back to the south.
- Considering the fully loaded aircraft, and high ISA +17, the TAS would be greater than at STD atmosphere resulting in a greater turning radius, and... to keep inside the valley they MAYBE had to increase the bank angle.
- At 45° bank the stall speed increase with 20% (1.4G). They most probably used max continues power. What speed? 120 knots? Or even slower (in case 2) due to terrain?
- The north wind, maybe gusting and turbulent, becoming a tailwind component during the last part of the 180 degree turn. It is not hard to imagine that they had small margins, not only scanning the instruments but also to look outside to keep clear of terrain.
I am also wondering, how is the Ju-52 accelerated stall behaviour? With max continues power, in a 30° (or 45°) bank? Probably not so nice. And how is the spiral stability, and what aileron position is required to keep a steady turn? Neutral? All factors influencing such a situation.