High-altitude helicopters

My posts have been mechanically-minded lately, and here's one more...

Last night, while looking for news accounts of the hikers stranded on Mt. Hood in Oregon, I learned that history was made in 2005 without my knowledge. When I first began reading about ill-fated mountain climbing expeditions, I wondered why helicopters were not used in the rescues. Then I learned that helicopters can't fly above 15,000' (basically) because the air is too thin. Well, that threshold has been broken - and a French pilot has actually landed on the summit of Mount Everest! Below are 2 incredible machines, both of them record-breakers:

Aérospatiale SA 315B Lama
The Lama was originally designed for the armed forces of India - which operate 72 of them, known as "Cheetahs" - and was 1st flown in 1969. This machine holds the record for reaching the highest altitude - 40,820' - of any helicopter. Bernd van Doornick piloted the Lama at an air show in Switzerland. He co-owns a company that carries out mountain rescues, and has 5,000 rescues to his credit.

Eurocopter AS350
This helicopter - the "Squirrel" - was developed in the 1970s by Aérospatiale (now Eurocopter) to replace the Lama, and is operated in many American law enforcement agencies. On May 14, 2005, test pilot Didier Delsalle alit on top of Mount Everest, the tallest mountain in the world at 29,035'. The flight broke the World Record for the highest altitude landing and take-off ever, for any flying machine on Earth, and sets an undeniable milestone in the history of aviation. This feat did not assure all high-altitude rescues, since there are many weather, weight, and other factors to consider, but it did make them a possibility. Until this point, it was considered extremely dangerous to land at Everest base camp, 10,000' lower, and several pilots have crashed in the attempt.

Here is an first-hand account of a high-altitude rescue in Colorado to illustrate that such flights are definitely not a given. An option to avoid putting lives of rescuers in danger is the remotely controlled alpine rescue helicopter.