Yes, so long as the aircraft has sufficient altitude, one can recover
sufficient airspeed [really, kinetic energy in the rotor system], even with
an initial slide to the rear if you let the fuselage turn in the same
direction as the rotors, to perform a successful autorotation. However,
there is an area in the flight envelope of every helicopter we called "the
dead man zone" within which a successful autorotation is very unlikely or
impossible. Hovering or flying at low airspeed within a few feet of a cliff
face is no big deal if not operating within the dead man's zone for that
aircraft.

During RVN, I suffered a total engine failure (N1 compressor ate itself) at
very low altitude, thankfully at a high enough airspeed (~100 Kt), in a Huey
(UH-1H) from which the textbook recovery worked perfectly: slight popup,
bottom the pitch, hard flare to rebuild rotor rpm while killing forward
motion and finally use the rotor system's stored energy to cushion the
machine onto the ground. It helps if you happen to be flying into the wind
at the moment of power loss.

I expect that most crashes from low altitude and high airspeeds in
helicopters to usually be the consequence of flying into something which
swats the machine from the air or from some sort of loss of control induced
by pilot control input, weather/wind, combat damage, or mechanical failure.
One can do that sort of thing in any sort of flying machine, eh?

I know that even in normal and cautious operation of our Skyhawk, there are
times when I'm flying the aircraft in situations which are probably not 100%
survivable in every circumstance, such as total power loss during an ILS
approach to an airport which has extended over water exposure on the final.
For that matter, driving around in my wife's Volvo isn't 100% safe, although
it is probably at least marginally safer than my Mazda MX-5 roadster.

Cheers,
Leonard
"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote in message
...
"Leonard Ellis" wrote in message
m...
I take it you guys are not helicopter pilots. I didn't see anything all
that scary in the video although some of it would have been far too
dangerous in most any airplane for my tastes.

Cheers,
Leonard

Most of it didn't look all that bad, as I understand it, you can
autorotate if you have speed even if you don't have altitude. But how
would you autorotate if you are hoovering with your nose 50 feet away from
a cliff? Pull the cyclic back and do it in reverse?
You are right - at least I'm not a helicopter pilot - so I don't have a
clue if it is easy or impossible..

--
Geoff
the sea hawk at wow way d0t com
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