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Auto pilot failure

Featured Replies

Today I fired up the ole bird and everything looked good. HOWEVER, approaching altitude I would have thought I was a porpose(?).The ole gal would not hold or even settle on the correct altitude. Vs was all over along with the speed,naturally.I have NEVER had a problem with this before. I have ttried to search but do you realize how many "keywords" you'd have to try? Maybe I didn't get the right one.Any way, I would appreciate any thoughts on this.Thanks,

Did the autopilot disconnect, or did it just have problems holding altitude and speed?Matt

It just continually hunts. Never settles down and as of yet has not disconnected. When I say "hunts" I mean by a coulpe of thousand feet.Never did this before either.Thanks,

Steve,As I recall from beta testing this happened to me when my load was out of whack. Check your load_stations configuration in your aircraft.cfg file and maybe post that section here. Having the CoG (center of gravity) out of bounds can give you this behaviour.Hope it helps,

Mats Johansson
PMDG Flight Test Dept
Boeing777_Banner_BetaTeam.jpg

| Asus Z270-A | Intel i5-7600K @ 4.8 GHz OC/H2O | nVidia Geforce GTX 1070 8GB OC/O2|

Here is the weight section. I will go back and reconfigure and see if that makes a difference. I was trying to simulate a cargo config here.Thanks for the help.[WEIGHT_AND_BALANCE]reference_datum_position= 52.730, 0.000, 2.120empty_weight_CG_position=-48.170, 0.000, 0.000max_number_of_stations=50empty_weight=83000.000empty_weight_roll_MOI=1482117 // was 1411540.000empty_weight_pitch_MOI=1912585.5 // was 1821510.000empty_weight_yaw_MOI=1594819.8 // was 1518876.000empty_weight_coupled_MOI=230.000//station_load.0=0.0, -48.350, 0.000, 1.050//max_gross_weight=153500.000CG_forward_limit=0.133CG_aft_limit=0.330station_load.1=0.0, -48.350, 0.000, 1.050station_load.2=12200.0, -48.350, 0.000, 1.050station_load.3=15000.0, -48.350, 0.000, 1.050

Here is my second attempt at loadout. It is a "standard" passenger load.Still no luck at vertical control. Maybe I should just reinstall but I would like to find out what brought this on.[WEIGHT_AND_BALANCE]reference_datum_position= 52.730, 0.000, 2.120empty_weight_CG_position=-48.170, 0.000, 0.000max_number_of_stations=50empty_weight=83000.000empty_weight_roll_MOI=1482117 // was 1411540.000empty_weight_pitch_MOI=1912585.5 // was 1821510.000empty_weight_yaw_MOI=1594819.8 // was 1518876.000empty_weight_coupled_MOI=230.000//station_load.0=0.0, -48.350, 0.000, 1.050//max_gross_weight=153500.000CG_forward_limit=0.133CG_aft_limit=0.330station_load.1=18180.0, -48.350, 0.000, 1.050station_load.2=6100.0, -48.350, 0.000, 1.050station_load.3=6000.0, -48.350, 0.000, 1.050Thanks

Looks ok to me Steve,Unfortunately the only advice from me at this point would be a removal and a re-install. Hope it helps,

Mats Johansson
PMDG Flight Test Dept
Boeing777_Banner_BetaTeam.jpg

| Asus Z270-A | Intel i5-7600K @ 4.8 GHz OC/H2O | nVidia Geforce GTX 1070 8GB OC/O2|

Hello Mats,I have done an uninstall with the uninstaller and then reinstalled just the 6&700. Wanted to check it out before I installed the 8&900.The problem is still there. I have listed the Autopilot section of the cfg file here.[autopilot]autopilot_available=1flight_director_available=1default_vertical_speed=1800.000000autothrottle_available=1autothrottle_arming_required=1autothrottle_takeoff_ga=1autothrottle_max_rpm=93.000000pitch_takeoff_ga=14.000000use_no_default_pitch=1 // 0 = Default to current pitch mode, 1 = No default pitch mode.use_no_default_bank=1 // 0 = Default to Wing Leveler mode, 1 = No default bank mode.default_pitch_mode=0default_bank_mode=0max_pitch=10.000000max_pitch_acceleration=1.000000max_pitch_velocity_lo_alt=2.000000max_pitch_velocity_hi_alt=1.500000max_pitch_velocity_lo_alt_breakpoint=20000.000000max_pitch_velocity_hi_alt_breakpoint=28000.000000max_bank=25.000000max_bank_acceleration=1.800000max_bank_velocity=3.000000max_throttle_rate=0.100000nav_proportional_control=9.000000nav_integrator_control=0.250000nav_derivative_control=0.000000nav_integrator_boundary=2.500000nav_derivative_boundary=0.000000gs_proportional_control=9.520000gs_integrator_control=0.260000gs_derivative_control=0.000000gs_integrator_boundary=0.700000gs_derivative_boundary=0.000000yaw_damper_gain=0.000000Does it look ok to you? My other addons seem to work fine, so it leads me to believe I haven't installed or changed anything that should effect this one.I appreciate the help.

Did you confirm you are placing the correct values into the FMC? They need to have precise data (or at least close within a rounding) of your weight data. ZFW and such is VERY VERY important for this. Also I found I can have this issue if I do not match the MCDU cruise alt. with the FMC's cruise alt. I have programmed in there. Assuring this accuracy has always cured the issue for me.

Yes Sir I have tried that. The problem is worse than that. It won't even hold alt. or speed when flown by manually setting the autopilot. or when using Flight lvl change, or Vs. Seems it just can't capture the altitude. One other thing I noticed when in V & Lnav is that any heading changes are real abrupt. Not the usual smooth turn.I am open for any ideas. This is really bugging me.Thanks for the help

Okay, friend. . . . this can also be caused by a draw/response issue with your graphics card and the memory on your machine. What I would try is maybe reinstalling your graphcis drivers and making sure that you have the latest versions of directX installed. Also be sure in your FS that you have the latest version of the FSUIPC module installed as that also was an issue with me before. I got a payware product that replaced my FSUIPC with an older version and I didnt realize it until I went to use my NG and my guages were gone.I know your guages are there, but this still may be a similar reaction, because the NG relies heavily on the FSUIPC and a lot can go wrong by just having the wrong version installed.In another area, something may be wrong with your aircraft CFG as well. When you uninstalled and reinstalled, did you be sure to MANUALLY delete ALL folders of PMDG? Last time I did a reinstall, it tookout a lot of the base textures and such, but it left my CFGs and my custom textures in there. Make sure everything is gone completely out of your FS directory before attempting the reinstall -- but lets wait on that until confirming FSUIPC and the drivers being up to date.Were there any Windows Updates done just before this started happening?Hope something in this list helps narrow it down.

Hello Christopher,I checked that my FSUIPC had not been changed, it is ver. 3.4.7.So that is good. When I did an uninstall and reinstall I did not check on the leftover file issue as you suggest. I will do it again and check this time. As far as the graphics, I can't see that as a problem because I was flying it 2 days before and have not done any graphics changes. Maybe I am missing your reasoning here though. I will first delete the FSUIPC ini file and try it before uninstalling.I appreciate your help here.THanks

Problem solved!!!!I have no idea why but after deleting my FSUIPC ini file everything worked like a charm. The ole gal sails along like the bird she is.I really appreciate the assistance Christopher, you put me on the right track.Thanks

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