Chopper crash

On Sat, 20 May 2006 16:47:52 -0400, "B4RT"
wrote:

Oh and FWIW; I think the water crash this thread is all about was caused
because the guy came in too hot, got behind the turbine, and couldn't arrest
the sink into the drink. Then the dude was so focused on getting the thing
back outa the water that he did a forward version of a dynamic rollover. If
he'd had a system failure, then why would he try to take off again?


That sounds like a very credible explanation. Especially the
characteristics of the aircraft support that (this is assuming the
Mi-14 to be similar to Mi-8 in this respect). The rotor governing is
probably not very good in the aircraft, in Mi-8 you are not allowed to
raise the lever from idle to full power in less than 10 seconds,
without a big Nr droop.

As a curiosity, the russian helicopters typically do not have a
Torque-meter at all. The transmission is over-engineered to take in
all conditions what the engines can deliver. In Mi-8 the power is
limited by the engine control system, which will limit the fuel flow
and let the rotor droop if too much lever is pulled.

In the final screenshots the landing gear is out. If it came out when
the helicopter hit the water, they must have affected the nose-over.

There was a comment in here about hin getting into low rotor RPM. That
doesn't really happen in a turbine ship unless you're already behind the
engine so far that you can't get the power up (or you have a low-side
governor failure). Chances are the dude pulled pitch too late and saw his
torque-o-meter peg at the redline and his VSI still saying "elevator-down".
Looked to me like he just ran outa airspeed, altitude, and ideas all at
once.

Bart


Mikko

Here is a higher quality video.

http://www.canada.com/globaltv/natio...-9a6241666200#
Click "Watch video of the crash"


It show the take off, the brief hover and the sudden
descent. It then cuts to a different shot
so it is impossible to tell how long the
maching was in the water. It is easy to
assume that there was no delay between the
'landing' and the take off but it is not at all clear.

This video also shows a spout of water
coming out of a hole in the under nose
"radome" as the helicopter rolls over.

Maybe the hard landing for some reason
caused a hole that allowed water to
enter the "radome" and it was this water that
caused the failed take-off.