WTF went wrong here? Bell JetRanger crash

[CharlieOneSix]

This must qualify for the shortest flight ever......
https://aviation-safety.net/wikibase/262192

A Bell 206B JetRanger II sustained substantial damage entering the hover at Langley Regional Airport (YLY/CYNJ), Langley, British Columbia for a Rotor Track and Balance.

[PHXPhlyer]

Any speculation from our resident whirly bird drivers?

PP

[CharlieOneSix]

As the helicopter was released from maintenace for a tracking and balance flight, one thought I had was that the tail rotor blades had been installed back to front - it has happened in the past. However a clear post-accident still photo shows that not to be the case. A pity we can't see all the fuselage before the accident - maybe a skid hooked on something.....or maybe it's as simple as over rotating with cyclic and not putting enough left boot in when he pulled up on the collective.

[llondel]

It almost looks like it was shoved from behind, or was attached to something and the attachment broke.

[Woody]

I think that we can safely say that the track and balance was incorrect, don’t think that it was a good idea for everyone to stand around the wreckage after the crew were out of the crash

[Boac]

From my limited helo experience I think the results could be obtained by applying full left hand and arm and pushing hard forward with the right arm while not moving one's feet enough?

I'm surprised one would 'fly' a helo to a 'track and balance check' rather than wheel it?

Anyway, the check needs re-doing.....................

[CharlieOneSix]

......I'm surprised one would 'fly' a helo to a 'track and balance check' rather than wheel it?....

The article below gives an insight into tracking and balancing. I would presume that a track and balance was initially done whilst the helicopter was on the ground and this flight was to fine tune those results. As the article says, tuning rotor track to give minimum airframe vibration does not necessarily mean the blades will be in track. A complex subject. My friend 'Wunper' - as in "one per rev" - on TOP is the expert in these things. I haven't been in contact with him for a few years so will try and persuade him to come over here.

http://www.dssmicro.com/theory/th_hist_ ... othing.htm

[Boac]

this flight was to fine tune those results