Propeller pitch control doesn't work correctly

[chriskilding]

Expected:

The propeller pitch Touch Bar control should move the pitch lever in the aircraft.

Actual:

When the Touch Bar control is changed, the pitch lever does not move, but the engine seems to slow down temporarily.

[chriskilding]

This may be a problem with the sim/cockpit2/engine/actuators/prop_ratio_all dataref.

Alternatively it could be the wrong dataref to use for this control.

[chriskilding]

The prop lever does move as you would expect if you

• use the dataref sim/cockpit2/engine/actuators/prop_rotation_speed_rad_sec_all instead
• set the prop Touch Bar slider range in the code to the appropriate range for the aircraft in question (e.g. slider.minValue = 0, slider.maxValue = 283 rad/s for the default Beechcraft Baron)

The fundamental problem with this approach, of course, is that it does not generalise to all possible prop aircraft - it only works for one specific aircraft. (E.g. if you try to use the 0...283 rad/s range on the freeware Dash Q300, only the first half of the slider range is usable; beyond that, the prop lever in the cockpit slides beyond the end of its range, and the prop RPM goes way beyond the maximum that the aircraft can handle.)

This dataref also only works for constant-speed props, not manual adjust props (of which there might be a few in the X-Plane freeware universe).