TheRedBadger Posted July 1, 2017 Share Posted July 1, 2017 I'm tearing my hair out since the A/P keeps doing this stupid, swooshy crap about the track set on flight planner. I do have the GPS/NAV switch set to GPS, it either doesn't stay aligned on the track, or the airplane decides to bank right of the track towards oblivion.... http://imgur.com/a/iELRe This is M. Spada's MD80 panel, on an SGA MD90. I've turned the A/P on and off, switched the GPS/NAV switch back and forth, but it always wants to go somewhere else instead! I've also changed the NAV 1 frequencies just in case, but I doubt that's the case (it has no effect). Also, pressing D to recalibrate the compass does make it go back to the course, but it ends up going past it, until I press D again.... that must have something to do with it. (the compass however, isn't affected by this) Carlos Si Link to comment Share on other sites More sharing options...
mrzippy Posted July 1, 2017 Share Posted July 1, 2017 Did this process work correctly with the panel that came with the SGA MD-90? Did you add this fix for that panel? COM80FIX.ZIP Still thinking about a new flightsim only computer! Link to comment Share on other sites More sharing options...
TheRedBadger Posted July 1, 2017 Author Share Posted July 1, 2017 Did this process work correctly with the panel that came with the SGA MD-90? Did you add this fix for that panel? COM80FIX.ZIP I think SGA's MD90 comes with the default 734 panel, which I've never used on the MD90. I've had this problem before, but I think it was on a different aircraft. I haven't, but I'm not sure if that'll fix the tracking problem (I'm procrastinating on doing that since I want to get to ATL first). I dont' blame ya if you can't help until I add that fix. This problem has everything to do with the compass; pressing D always makes the aircraft "flip" it's rabid turn in the other direction, even though it's not flying the heading, but supposed to be flying nav. I tried direct-course but the problem persists. Flying the heading comes with oscillation, but it dies down. Aaaaaand now it's flying some different course, even when heading is active..... Yaw-damper hasn't had an effect on the flight (it does cause the rudder to do some flapping on the ground so it's definitely active). One more observation during the flight; the avionics turned off, and I noticed the left battery switch was "off". I turned this on and things have gone smoothly so far... it follows the track with ease, so far... Carlos Si Link to comment Share on other sites More sharing options...
jgf Posted July 2, 2017 Share Posted July 2, 2017 The AP receives its signals from the indicators, if any of these is not enabled in the aircraft.cfg or, if applicable, not powered in the aircraft (via switches or circuit breakers), the AP will have no input for that axis. Link to comment Share on other sites More sharing options...
mikeandpatty Posted July 2, 2017 Share Posted July 2, 2017 Sometimes the autopilot integration values are not realistically matched to the airplane's roll / pitch control sensitivities and therefore overshoots commands. I have often corrected this in freeware aircraft using the following values in the [AUTOPILOT] section of the aircraft.cfg file: (replace current values with the following) - //NAV Tracking Parameters nav_proportional_control= 20.0 nav_integrator_control= 0.45 nav_derivative_control= 0.00 nav_integrator_boundary= 0.50 nav_derivative_boundary= 0.00 //GS Tracking Parameters gs_proportional_control= 14.0 gs_integrator_control= 0.65 gs_derivative_control= 0.00 gs_integrator_boundary= 0.70 gs_derivative_boundary= 0.00 yaw_damper_gain=1.500000 These are especially good in tracking an ILS smoothly, and the NAV integration may help in tracking a GPS course. For me, it has helped in many cases. Link to comment Share on other sites More sharing options...
copperpen Posted July 2, 2017 Share Posted July 2, 2017 I have not used this aircraft before, so out of interest, I installed it and then added the Spada panel. Have flown it for an hour now using the AP on a flightplan, and have had no deviation from the planned track. Link to comment Share on other sites More sharing options...
johnhinson Posted July 2, 2017 Share Posted July 2, 2017 Also, pressing D to recalibrate the compass does make it go back to the course, but it ends up going past it, until I press D again.... that must have something to do with it. (the compass however, isn't affected by this) Key D adjusts for Gyro drift, which I understand should not affect modern compasses, so it sounds to me as if the aircraft might be using the wrong type of compass. Try turning Gyro Drift off in the FS Realism settings, that might just do the trick. Worth a try, anyway. John http://www.adventure-unlimited.org My co-pilot's name is Sid and he's a star! Link to comment Share on other sites More sharing options...
TheRedBadger Posted July 4, 2017 Author Share Posted July 4, 2017 Can't recreate the problem on the MD90 (panel worked fine on the MD88). The only culprit is that battery switch remaining off which I noticed when the avionics turned off, but I'm not sure. Carlos Si Link to comment Share on other sites More sharing options...
martinstebbing Posted July 4, 2017 Share Posted July 4, 2017 I know this sounds basic, but I get the same symptoms when my flightplan has not loaded into FS9 for some reason! Look in the FS9 menu bar/flights and if the Navigation Log entry is greyed out, that's the problem! Well, probably not that, but worth a reply, just in case... Link to comment Share on other sites More sharing options...
TheRedBadger Posted July 6, 2017 Author Share Posted July 6, 2017 I know this sounds basic, but I get the same symptoms when my flightplan has not loaded into FS9 for some reason! Look in the FS9 menu bar/flights and if the Navigation Log entry is greyed out, that's the problem! Well, probably not that, but worth a reply, just in case... Not sure if I can do that anymore since the flight's been landed a while back; should've saved a flight with the problem in tact :1 Carlos Si Link to comment Share on other sites More sharing options...
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