Quote:
Originally Posted by edgemar
Is yanking on the collective the right thing to do when you lose a tail rotor? What is the procedure..if any?
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It depends on when the tail rotor failure occurs.
Yanking up on the collective increases power and torque. Since you've lost your anti-torque drive (the tail rotor) you do not want to pull up on the collective - that would exacerbate the situation.
If you're hovering five feet off the ground the usual procedure is to close the throttle. The spin you would be experiencing would be reduced and you would immediately begin to settle to the ground. You could also then pull up on the collective to cushion your landing, depends on the situation. This is all happening far quicker than it takes to explain it, you really have to act quickly.
In cruise flight, it also depends. If you're flying along at 100+ knots and you lose your tail rotor, the vertical fin acts like the feathers on an arrow and will help you keep your nose pointed somewhat straight (though probably with some yaw). At some point you will have to close the throttle and enter an autorotation to put the aircraft on the ground without power.
If you're flying along at altitude at a slower speed, lets say during take off or landing you have to enter an auto immediately but if you're too low and too slow you may be kind of screwed. There simply may not be enough altitude or airspeed for a successful auto.
When my TR failed I was on takeoff a couple hundred feet high and about 50 knots. My autorotation was a spiraling right turn but controllable. Any slower at time of failure and I would have been SOL.
The Bell 222 in the video was too low and slow for any kind of successful autorotation. He also lost the actual TR from the aircraft. That changes the center of gravity of the aircraft making a bad situation even worse as far as controllability.
The one thing the pilot could have done (and he may have tried it) is close the throttle and pull up on the collective just before impact. Pulling up on the collective (with no power to the rotor system) uses the last bit of energy in the rotor to cushion the landing.
Edit: Just read Seahawk's post - yes, wheels vs skids would make for a different procedure in some cases and many helicopters have may have small variations of what I wrote.