I improved the R66 flight dynamics somewhat, but I cannot find how to model dissymmetry of lift. According to the SDK, there is a parameter for this called right_trim_scalar, but it doesn't seem to affect anything whatever numbers I try.
Most of the SDK parameters are not for helicopters. There is a small section of the aircraft.cfg which deals with helicopters. Unless you use those parameters you will have no effect on helicopter flight characteristics.
OK the Robinson has a rotor trim control knob. It applies right trim if you pull it back. A scalar on that should scale the effectiveness of that trim, but the scalar will do nothing unless you operate the control
First question is which of the three basic helicopter models, Bell, Robinson piston engine or EH101 multi turbo engine are you using?
In post#4 above I stated that the stock Robinson has a right trim control whose effectiveness varies with the right trim scalar. With a scalar of 1.0 it is very powerful and counteracts the dissymmetry of lift as you accelerate. So that is already present and modeled. However I made the point that the scalar has no effect until the control is used.
The scalar will have no effect on the Bell model. I’m thinking it might work with the EH101 model, but I’d have to check.
The three models are Bell, Robinson and EH-101.
The Bell model has some aerodynamic stuff in its air file and is for a single heliturbo engine.
The Robinson has mostly piston engine stuff in its airfile though it also has records 1101 and 1534. However these two are full of zeros so must be place holders.
The EH-101 has only heliturbine engine records in the air file.
There is very little you can do about aerodynamics with the Bell model and it does not have right trim scalar adjustment
The Robinson and EH-101 have aerodynamics factors in the aircraft.cfg and they both have right trim scalar adjustment.
So if you want to address the effects of lift assymetry you need that scalar. If you add it to the bell model it will do nothing.
The SDK has examples of each of the airfile types in the "Flight Models" sections.
Another option is to determine when the effect should occur, and intercept the control inputs so you add the effect through the controls, transparently to the user. As long as the end result is accurate (both effect and controllability) then how you achieved it is pretty irrelevant.