Has anyone had and solved this problem?I have been having a problem with autopilot speed control and (lack of) throttle response after LONG (many hour) periods of flying on the autopilot. This happens on different aircraft (e.g. FSD Piaggio Avanti, Aeroplane Heaven Virgin GlobalFlyer) so I believe its ultimately a problem with settings in one of my .ini or .cfg files.Speed control is gradually lost (plane speed sometimes drifts up, sometimes down) from the A/P setpoint. There is no response to a change in setpoint. Most aggravating part is that when I shut the A/P speed control off, the throttle doesn't respond to manual changes either.Sometimes I get control back abruptly after several minutes. Usually, I have to reset the flight.I'm using FS9.1, FSUIPC 3.47 (registered), XP Home SP2Thanks,

Does your panel/aircraft have an Auto-Throttle switch? If so, you may want to disengage and re-engage that and see what happens.

I would pause the flight and reselect the a/c from the menu. This has the tendancy to reset any bugs that crop up. I'd also check for interference from your joystick (ie noise).best

Thanks for the suggestions.ssurjap - Neither of the planes uses autothrottle arming and these setting are off in aircraft.cfgs. Cycling the speed controls doesn't help the freezeups.rightseat - From past experience reselecting the a/c works but it really seems to mess up the Avanti. I put the FSUIPC filters on my joystick axes and didn't get an Avanti freezeup but still had speed control problems.I made this same post on the FlightSim forum (#128734) and got a helpful suggestion from fbobum - in FSUIPC map a hotkey to the "Regain control of all engines" item and then use it upon "freezeup".This solved both freezeup and speed control issues in the Virgin GlobalFlyer. As noted above, I didn't get a freezeup on the FSD Avanti but the FSUIPC hotkey didn't solve the speed control problem (after being on A/P with Speed engaged for a while, throttle creeps up and plane speed increases. If I turn speed control off, I can use manual throttle to bring speed back down. As soon as I turn Speed back on, rpm and speed shoot back up. Somehow the speedbug setting is getting ignored. As far as I can see, nobody has posted this one on the FSD Support forum).Thanks again,