Well the Training imparted plays the role as it must. A Vehicle of such caliber must not be ditched in the terrains where its built for.
OK, let's work this out in some detail.
There are three battlefield hazards facing any helicopter in the mountains. High mountains and lower ones alike, for two of them; high mountains alone for a third.
First, weather and flying conditions. Mountain terrain is windy terrain, with wind of fluctuating strength flowing across natural features - ridges, slopes, ravines - in unpredictable manner. Helicopters are difficult, unstable flying objects. Unlike older planes, when power is cut off, they don't just glide down, they plummet, like bricks. In such uncertain wind conditions, pilots find it a full-time job to keep in the air. There are unexpected pulls and pushes, and a high state of alert is needed to merely keep flying.
Second, the enemy. The same uneven terrain that builds uncertain winds also provides a thousand and one nooks and crannies, folds in the surface and natural walls which hide shooters and their (typically now) MANPADs. After coping with wind and weather conditions quite different from the plains, pilots need to watch out for a camouflaged soldier popping out from nowhere. This, too, is substantially different from the plains, where hiding places can be spotted early.
Third, in the case of the Himalayas and the Karakorum, whiteout. Flying in snowy conditions is particularly dangerous because it is unrelieved white all around. A pilot loses orientation. It is difficult to gauge whether the machine is flying straight, at an angle, or tilted. The artificial horizon helps, but every second glancing at an artificial horizon is a second not looking out for a cliff face straight ahead.
For these reasons, flying in general in the mountains is a *****. Pilots don't like the idea. Flying an attack helicopter adds
To the tension. On top of everything else, you have targets and targets that shoot back. Attack helicopters aren't meant for the hills. In fact, listening to wise guys talking about what airpower could have done for the IA in 62 makes me feel ill. It could have done nothing, but that's a different thread.
It is a different thing that normal helicopters labour at altitudes like Saltoro. The Dhruv was specially engined for that extreme high level performance. The LCH, its derivative, handles heights as well. What it means is not normal attack helicopter operations. Instead of flying along the nap of the earth, instead of lurking in hollows or depressions and suddenly bobbing up with cannons blazing is not the norm any more, though it can be done on occasion. Instead what is likelier is closely coordinated action as mobile, airborne artillery, either offering covering fire to an assault team, or pouring in counter-preparatory fire on an assault team about to attack our own positions. The high altitude bit is not to act as an assault heli any longer, but more to provide artillery support where the other guys had never expected artillery support.
We could talk about these scenarios if you like.