I looked at that film. From this download I don't think there is enough
video information to resolve the blades. In addition, the helicopter is
out of view for the most critical point of the flight. However it does
appear briefly right when it is most useful - it appears to me that the
tail rotor struck the ground immediately before the craft spun out of
control. It is not unreasonable to suppose that the tail strike could
have damaged the rotor, causing the crash.

Prior to that point, the craft appeared to be flying straight and in
control, but not lifting off well. This could be due to overloading; it
could also be due to wind conditions, pilot error, or topography, with
altitude as a possible contributing factor.

But look closely - there is an instant just before the spinout where the
tail rotor appears to contact the ground. That's probably your most
immediate key. I would expect that =why= the rotor struck the ground
would be the main focus of the investigation.

Jose
--
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except there's no God, and there's no dice. And maybe there's no universe.
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