What could cause cyclic to 'let go' in a hurricane?

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thestructured
Posts: 157
Joined: Thu 24. Dec 2015 20:13:20

Last time I was out I flew with VTX blades for the first time, which I know can be harder on the power system. I was doing hurricanes and in the middle of one cyclic 'let go' and the heli kind of did a sideways flip out of it as if it stalled for a second.

I'm not sure what caused it. My only guesses are either too high or too low cyclic gain (I'm around 60 or 65) or the wider cord of the blades causing the heli to stall out or something. Any suggestions?
CFerry
Posts: 32
Joined: Sun 04. Feb 2018 15:31:41

If your forward speed was very fast and it did a sharp 'up' elevator movement (assuming skids-out hurricane), it is likely a pitch-up.
If this is what is was, you might not have enough cyclic authority, which could be flybarless related or something else.
You can try: increasing cyclic gain or increasing the cyclic ring setting.
It happened to me on my Align 550 dfc during fff due to cyclic servo horns being too flexible.
Someone else may chime in with more suggestions.
Chris
thestructured
Posts: 157
Joined: Thu 24. Dec 2015 20:13:20

Thanks..it was inverted tail forward, the tail swung in towards the center of the circle and the heli ended up with the top of the rotor facing me, a really freaky moment.

I'm redoing the setup on this heli (crashed) so I'll check it all over..maybe I had too much pitch and not enough cyclic ring as you said. Though this same setup never did this until I put on those VTX.
CFerry
Posts: 32
Joined: Sun 04. Feb 2018 15:31:41

From your description, it confirms, in my mind, an inverted pitchup.
Must have been quite startling indeed :shock:
I've never run VTX, so I can't comment there.
ZeXx86
Site Admin
Posts: 12836
Joined: Mon 29. Apr 2013 16:06:44
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You can increase Cyclic Ring. If there was no mechanical range it can happen easily. Used blades are playing major role in how much angle you will need.

The bigger collective pitch range, the bigger cyclic ring you will need.
Spirit System developer
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