Mr. Carson,
I think you've got a feet for pounds issue on the 28,000 for the CH53.
A 28,000 feet, 95F test would require a very warm day in the Karakoram.
SansAnhedral,
Is that flying to the mountains at 15,000ft, or landing amongst the mountains at 15,000ft? Landing at 9000ft would be rather easier.
32 guys must weigh 6000lb, so even with maximum extra tanks that only makes it to a 500nm radius from the brochure, against just over 600nm empty, so presumably that rescue must have been air-refueled, and the take off and landing in the mountains could have been almost empty of fuel.