Yes a B3 Squirrel did land on the top of Everest, until the French were told they were in the S**t for not having permission, then suddenly claimed it had all been a funny mistake, and they actually landed somewhere else.... The video of them landing on a mountain that looked remarkably like Everest, but couldn't have been could it? used to be on the Eurocopter site...
Dohh! Heliport just beat me to it, by 1 minute! Gotta type faster..