How helicopter flight controls work

Has an airplane ever used stick twist for rudder control?

Yes, the FBH system RAH-66 Comanche used a rotary control for the yaw channel.

The RAH-66 Comanche used a twist in the pilot's control stick to control the rudder / yaw inputs. It had no rudder pedals. (Yes, a helicopter is an airplane).

Comanche was unfortunately canceled towards the end of LRIP (Low Rate Initial Production) in 2004 when the program transitioned to EMD (Engineering and Manufacturing Development). At this point, at least two prototypes were flying. Test and development flights took place from 1996 to 2004.

Excerpts:

"... included the RAH-66 Comanche design a 3-axis sidearm regulator with limited displacement and limited displacement (the cyclic pedals and Yaw pedals replaced) to control the longitudinal, lateral and yaw axes. A proportional collective with a displacement of approximately 6 inches was used. An improvement tailored to the Scout mission was this Inclusion of limited control in the vertical (fourth) axis of the sidearm controller. This enabled the pilot to command stabilized climbs and descents with the altitude maintenance system activated. This was mainly used for vertical unmasking and remasking maneuvers that allowed the pilot to fly without temporarily disengaging the autopilot. "

- "Impossible to resist" - The development of fly-by-wire technology for rotary wing aircraft (PDF - Paywall)

and

"The RAH-66 Comanche program proposed 4-axis control (Harvey, 1992), but this approach is now in question."

- A four-axis hand control for helicopter flight control


( Source )

Note that either the controller configuration '3 + 1' or '4 + 1' would probably have been set for the Comanche as all the cockpit images seen have a sidestick and a collective stick with no pedals.

As mentioned in the first block of text (Impossible to Resist), 3 + 1 (collective) was the final form, although the cyclic had some control over the vertical axis (as described). I've added the emphasis in bold and the reference to "sidearm control" opposite "cyclical" in parentheses.

ymb1

Very interesting! Hope you don't mind if I add the excerpts.

KorvinStarmast

@ ymb1 No, I don't mind, thanks.