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Helicopter Lands top Mount Everest

Posted by Hemos on from the new-methods-of-flying dept.

FlyByPC writes "The Eurcopter team has succeeded in landing a helicopter on Everest and returning safely to base, setting another ultimate aviation milestone -- for highest-altitude takeoff and landing. Interesting pictures of Lukla airfield, as well -- essentially a runway carved out of a mountainside."

2 of 47 comments (clear)

  1. Re:Hold up by hedronist · · Score: 5, Informative

    Short version: Yes, helicopters use runways.

    Long version: Most people assume helicopters just jump off the ground and are suddenly flying. The reality is a good deal more complex than that. (Which is a true statement about almost everything to do with helicopters.)

    1. When a helicopter first lifts off the ground it is inside its 'ground effect envelope', where part of its lift is coming from pushing air against the ground. Once it is above a certain height (varies by aircraft -- anywhere from 10 feet to 80 feet), the ground effect falls away and it is now fully airborne.

    2. Pure hovering (outside of the ground effect) takes an amazing amount of energy. It also has the danger, if maintained in one place on a still day, of creating a torroid of moving air: first pushed down by the blades, then sucked up and over the top to be pushed down again. This means the copter now has to push harder and faster to make up for the fact that the air it is pushing against is already moving down at some speed.

    3. Most fly time in a helictopter is spent moving forward in the air. The disc created by the spinning blade generates lift as it moves forward through the air. In fact, helicopters are called 'rotary-wing aricraft'.

    4. During takeoff, a heavily loaded helicopter -- or one operating at high alititude -- will want to stay inside its ground effect envelope while building up forward speed. Once it's going fast enough to generate lift forward motion, then they can start to gain altitude and move out of the ground effect.

    One page with more info: http://www.helicopterpage.com/
    Peter
    284th AVN Co, ATC, 8th Army

  2. Did you make up this statistic? by BraceletWinner · · Score: 5, Informative
    From http://www.mounteverest.net/story/MountEverestKill erMountainsAnExplorersWebSeriesOct292003.shtml/ (a link from 2003):

    To date, there have been 1,924 ascents of Mount Everest (more than 1,300 different climbers), and 179 people have died. The overall fatality rate is thus about 9% (fatality rate is defined as successful summits compared to fatalities). However, since 1990 there has been an explosion of summiteers and fatality statistics have changed. Up to 1990, the Everest fatality rate is a whopping 37%, with 106 deaths and only 284 summits. Yet from 1990 until today, the rate has dropped to 4.4%; 73 people have died, and 1,640 have summited. Thus, the rate decreased to about eight times less than the pre-1990 fatality rate!

    The fatality rate from attempts is even less since more people attempt it each year than actually summit. Look something up before you spout off stats that sound good.