Non-linear throttle axis calibration

[zip]

Hello Pete,

I had a question that stems from my recent foray into a certain ATR 72 that can be very hard to control on the ground when using mapped throttles. At issue are goobles of power that transforms the aircraft, and only this particular ATR, into a rocket on the ground by barely nudging the throttle (half a mm). The response with any other a/c, including other turboprops such as the 1900D have no such issue.

You have a very nice curve response on the aileron/elevator axes, but there is no such thing I have found to affect the response of engine throttles (single or separate).

What I'm looking for, and what I may have missed, is a method to adjust the curve of throttles so it is more sensitive in the low range (to allow for less response, more throttle movement, in the idle range) and then moves to a more linear mode. A sort of J curve.

Is that in existence, or in the works?

Cheers,

Etienne Martin

[Pete Dowson]

What I'm looking for, and what I may have missed, is a method to adjust the curve of throttles so it is more sensitive in the low range (to allow for less response, more throttle movement, in the idle range) and then moves to a more linear mode. A sort of J curve.

Is that in existence, or in the works?

No, it's really never been mooted. The throttle systems I know are pretty linear, on purpose I think so that it is easy to preset specific thrust needs.

It sounds like the modelling of the aircraft you are using is a bit off if there's little adjustment possible in the low end.

However, I'll add the request to my list. I'm afraid it won't be done immediately.

Regards,

Pete

[zip]

Hi Pete,

Thanks for your reply. Upon further thought, it came to me that an off-center "S" curve (as coded for a centered axis) may very well work for a throttle to smoothly transfer from reverse to idle to max provided the center of the "S" can be offset (in this case, the low range).

This would allow for smooth transitions between idle and either reverse/normal thrust and probably help with the deadband as well.

Sincerely,

Etienne Martin

[Pete Dowson]

Upon further thought, it came to me that an off-center "S" curve (as coded for a centered axis) may very well work for a throttle to smoothly transfer from reverse to idle to max provided the center of the "S" can be offset (in this case, the low range).

It would have to be that in any case for the separate throttles with reverse range, but the single throttle axis has no reverse range, so then your "J" curve (actually the upper part of the S curve) will do.

Pete