When an aircraft is in a bank and you take your hands off the controls, it should naturally right itself back to wings level. Where can I find the parameter to increase/decrease this tendency?

Um, that is not correct. The vast majority of a/c will maintain bank with little to no further input. Opposite aileron/rudder is required to return to level flight.

That's usually affected by the dihedral.

Um, that is not correct. The vast majority of a/c will maintain bank with little to no further input. Opposite aileron/rudder is required to return to level flight.

Fine, but does anyone know what parameter affects this? Is it in the aircraft.cfg or the .air file, and what is it called?

Fine, but does anyone know what parameter affects this? Is it in the aircraft.cfg or the .air file, and what is it called?

There isn't a single parameter because aerodynamic rolling moment doesn't depend on bank angle. The aircraft's response is determined by the lateral derivatives in the .air file. There are three sets of derivatives - one for rolling moment, one for yawing moment, and one for sideforce. There are traditionally all in Table 1101 of the .air file. Additionally there are scaling factors on some of these based on angle of attack and Mach number.

There is more than one parameter that affects this.Wing Dihedral in the aircraft.cfg but I do not recommend changing this.Table 1101 in the .air file under Roll parameters: CL_beta roll moment (is the best place to start) and CL_rThe CofG positionThe wing position.And a thousand other little things which will all affect the behaviour. That's the problem with flight dynamics. There is no single parameter as it is a combination of all the elements that affect the planes handling. But start with table 1101 in the .air file (I recommend aircraft airfile manager (aam) for editing this )