David Megginson <[EMAIL PROTECTED]> said: > Curtis L. Olson writes: > > > Going with the principle of least surprise, I prefer the current > > behavior. If I'm flying along with the autopilot and everything is > > nice and trimed out, then I disable the autopilot, with your patch I > > could suddenly be catestrophically out of trim. I'd rather the > > autopilot leaves the trim where it is when disabled. > > That's what happens in real life as well -- if the plane is in > turbulence, and the AP has to give up, it might leave the trim in a > totally ridiculous position.
There is some hesitantion on my part to speak up on this issue, as it certainly isn't something I know a lot about. It seems that from what I remember reading, at least in some aircraft, the autopilots that actuate the trim wheel are using it in a way similar to how a live pilot would. In other words the elevator is used to control aircraft pitch and the autotrim kicks in to releave the pressure on the servos that control the elevator. To simulate this the autopilot code would need to know how fast the trim wheel motor was. Then it would replace a tiny bit of the offset from 0 in the elevator control with an apporpriate offset in the elevator trim setting. The elevator would be more responsive, and the trim would be constantly following behind trying to trim out the latest elevator setting. If this is true, then it could alleviate some of the problem caused by the current method, since in a turbulant situation the autotrim might not have cancelled out all the elevator before the autopilot disengaged. Best, Jim _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
