Co-Pilot and tail induced drift question.

[Daniel Wee]

Hi,

I've been thinking a bit about devices such as the co-pilot that uses the horizon to level the heli and I know that some of you here are using the co-pilot. I have a question here and would appreciate if someone can give me some info on it.

Since the heli is being levelled, doesn't this result in an intrinsic drift as a result of the thrust generated by the tail rotor? When I hover my heli, I observe that in a perfect hover, the heli is actually tilting a little bit, and I assume this is to counter the said tail rotor thrust. But how does the co-pilot work around this tail rotor induced drift?

Thanks.

Daniel

[Tophinater]

If the force the tail rotor exerts on parallel to the plane of the cyclic then that tilt will not happen. The tilt is because the tail is exerting a force below the cyclic plane which is compensated by left or right cyclic. If you want later I can create a FBD which might help you understand it better. Not sure exactly how a co-pilot is set up on a heli but I would imagine that this effect would be neglagable as long as you calibrate for it.

[Daniel Wee]

I understand what you're saying. What I am really interested in is the calibration process - just how precise is this process given that the induced thrust is not constant. A static calibration will never be able to deal with varying side-thrust.

I wonder if there are other strategies for keeping a heli in one-spot, assuming that there is no other wind vector in the equation.

Daniel

[TMorita]

As far as I know, the co-pilot only levels the heli.

It doesn't keep the heli stationary.

It's a "save your heli" device, not an "inertial guidance system".

Toshi

[Terry S]

you need to mount the sensor at the angle you see the heli at normally

Terry