I was going to publish in the last blog that helicopter rescue above Base Camp had only occurred once but I thought I should check the internet first. The following is from GreatOutdoors.com June 2005.
Heretofore, the summit of Everest was utterly out of reach for helicopters. In fact, just landing at base camp, 10,000 feet lower, was considered a life endangering feat. Several attempts resulted in crashes. KC Madan, a Nepalese military pilot , became a hero when he landed his machine at Camp II to rescue Beck Weathers and Makalu Gau after the 1996 tragedy. Now, pilot Didier Delsalle has landed on the summit, where he remained for two minutes.
I was absolutely amazed.