Using the radar returns and Google Earth I've plotted the salient points. The line assumes staying at 7600ft which obviously wasn't their intention. Even maintaining the assumed rate of climb from the returns they would have crossed the summit at 8100ft. One doesn't know that they weren't being affected by shear/turbulence etc at the time of radar returns....
If this had been a VFR transit (low level or not) then they could well have seen reducing weather ahead and commenced a climb up to the their MSA/MOCA which would've been about 8900ft. The only thing I can assume at this stage is that they encountered a catastrophic weather event as they crested the ridge. Even the loss of an engine (on an empty aircraft like this) wouldn't have been a massive drama....
Remember, this was a military exercise. They may well have departed IFR but then once clear of the wx at ENEV, cancelled and gone VFR and possibly even descended into Low Level for the remainder of the transit. The TAF at destination gave no indication of anything untoward apart from the gusts increasing.
TAF ESNQ 151130Z 1512/1521 20015KT CAVOK
TAF ESNQ 151430Z 1515/1522 20015G25KT CAVOK
Similarly the TAF on departure didn't hint at anything unusual for Norway in March:
TAF ENEV 151100Z 1512/1521 21015KT 9999 -SHRA FEW008 BKN020 TEMPO 1512/1521 21025G35KT 4000 SHRA BKN012
