Phil Croucher wrote in his "Helicopter Pilot's Handbook":

quote:
"If you're likely to be ending up in trees [...] aim between to tops, tail first or low, or at least moving gently backwards. The worst thing to do is go in nose first, because the engine and gearbox will hit the ground before you do (and you're in the way!) :eek: "

...your thoughts?

His second theory which does not quite fit into "try to get a tad of airspeed" - but, fair enough, he's talking here about getting into a clearing, not when you a lot of space at hand to run it on:

quote:
"In a vertical autorotation, there is a phenomenon called dynamic stall that will help, where an aerofoil that is rapidly stalled can produce double the normal lift, just for a moment, because the breakup of the boundary layer on top is delayed for a while, if indeed you don't actually create little vortex along it that improves lift even further. Do not try to gain speed, as you will split the lift vector and increase your rate of descent."

As I said, his words, not mine. You guys are the experts and I really appreciate the wealth of knowledge in this forum! This thread in particular 'cause I have many occasions flying my little single over lots of trees and would like to survive if the engine says good bye :rolleyes:

Phil

The trees and tail rotor low thing was sourced from at least two guys from Remote Helicopters who had ended up in trees, and after the second time, one of them still carries a length of rope in the cabin so he can get down with it. They also pointed me to a US Army article called "How to crash a helicopter" which said pretty much the same thing.

The second bit was from an article by Dennis Venturi in Helicopters magazine several years ago (it's a Canadian one). I'm not an aerodynamicist, but it seems to work, as I found when playing around near powerlines. I still wouldn't try for any more cyclic than is required to counteract the normal nose-down tendency. Like all advanced techniques, to be taken on board but not necessarily practiced until you really have run out of ideas.

And, as somebody said, a real engine failure is nothing like what you get in practice.

Phil

Shawn, Could it be the article "Cyclic Back NOW" from heliops issue 24? I recall the same advice from the article, but I don't have it here to confirm.

Thanks to Paco and google => http://users.adelphia.net/~luv2hang/crash.htm

I believe that was the article.
We have to be careful of having people do things because that's the way they've always done it, or that they've only had one set of experiences for a particular emergency. I remember talking to the US Navy helicopter training people many years ago -they had just transitioned from the UH-1 as a basic trainer to the Bell 206. One of them said, when doing hovering autos, you had to push the cyclic forward in the UH-1 and had to do the same in the 206. I asked why you had to do this and was told it was because it had always been done. When I asked if they had ever tried not pushing forward in a hovering engine failure (because you certainly didn't need to in the 206, and even my limited experience in the UH-1 said you didn't need to), I was told that basically they were not allowed to not push forward...