Super lucky pilot!
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I guess the front fell off the tail rotor assembly… 
Glad to see the pilot was ok.
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Tough little machine, that robbie!
That poor Cessna, just sitting there, minding its business!
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It was made a million times more interesting by the contact with the Robbie.
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HI folks, first post here, only been registered 9 years…
Supposing the yaw rate was triggered by the tail rotor failing somewhere - how long would the pilot have at the point of failure to try and counter the rotation? I guess it needs pretty much to be an instant reaction. I’m not sure I’d be capable of anything much considering the forces spinning at that speed.
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I’m not a helicopter pilot, but if the tail rotor fails, I don’t think the pilot has any yaw control at all at that point. I guess dumping collective might help but then you have a whole other problem to deal with.
Welcome to the asylum Vitesse21! 
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That would have been my first reaction… but then again it comes with the territory.
1st chop the throttle then dump the collective.
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I’ll bite: why?
What does chopping the throttle do for us?
Eventually we’re going to get a 300 or 400-level college course in helicopter aerodynamics out of you, just by collating all of your posts where you put on your professor cap for us. 
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Not a helo maniac, but I guess it’s like the prop shaft of an airplane; it removes the torque on the rotor shaft…?
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I was about to ask the same question but then…
this…
It’s brilliant in its simplicity. If you have no torque applied you also have less counter-force applied to the aircraft hull and thus you lessen everything else.
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It won’t stop the yaw rotation though…but maybe slow it enough that you can still possibly judge your altitude before having to add collective. I guess at this point all you are looking for is a survivable impact rather than a fatal one.
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Not stop it, agree. Just judiciously reduce forces applied.
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Yep, you all nailed it. It’s even more of a reduction than the prop/shaft analogy. A prop is fixed to it’s drive-line. In a helicopter the engine is attached via a clutch mechanism. If the engine is producing less RPM than the clutch, the system freewheels.
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It would have been interesting to see how he lost control to begin with. When this came out on reddit one poster who implied familiarity with the school said that the pilot was “experienced” meaning in context something beyond a 20 hour solo student.
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Thanks for the reply and the welcome Paul!
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That answers my next question - Why not have a mechanism that disengages the rotor from the gearbox?
So, given enough altitude. Once the inertia of the rotating fuselage has been overcome and it stops rotating and provided there is some aerodynamic stability (centre of pressure behind the CoG) you basically have a gyrocopter and should regain some control?
No. With no tailrotor and insufficient forward speed, there is no stopping the spin without ground (or Cessna) contact.
To illustrate: here is what the Robinson manual recommends for a tailrotor failure in cruise flight (I am paraphrasing):
Close the throttle past the overtravel spring (to override the governor) and lower collective to enter autorotation. ABOVE 70 knots there MAY be sufficient weathervaning to allow fight with some minimal power. However, before slowing below 70 knots you must close the throttle and enter autorotation.
Your gyrocopter analogy would work if there was a rudder and sizable tail. But the trim fin (as it is often called with helicopters) is just that, a small surface that keeps the helicopter roughly in trim during cruise flight with minimal rudder pressure. But that’s with the tailrotor still spinning and still supplementing the fin to counter torque.
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