Multiple Autopilot Failures after T/O?

[threebears 14]

I'm following the Tutorial #1 manual to the letter (I think).  Everything looks as it should but as soon as I get past 'gear up' and the FD becomes live various things 'switch off'.  Principally the #1CMD (autopilot) disengages, along with the auto thrust.  Although sometimes the CMD will re-engage, the A/T will not.  The a/c will not climb without getting into a stall, no matter what I do to the power levers (remember A/T has disengaged and CMD is supposedly inoperative).  Any suggestions?

I've just tried again, this time VNAV deselected itself and speed refused to rise above 145kts!  LNAV did stay and the heading was followed.  The manual says LNAV might not engage, not VNAV!  I wonder if this is becuase I updated the Navigraph data to AIRAC 1812.  I could test that by restoring the 'old' (shipped) NavData which I backed up.  Hmm.

 

Andrew

Edited December 3, 2018 by threebears
Additional info

[MarkJHarris 128]

Weird one. What FMA modes do you have selected on departure? What altitude you you first try to select Autopilot? What settings are in your FMC, in terms of selected thrust, de-rate and assumed temperature?

More information needed.

What I can tell you is the autopilot will only engage when the aircraft is in trim. 

[threebears 14]

Thanks Mark.  I'll write it all down and answer later.

[Ephedrin 418]

Do you use FSUIPC? If so, delete the ini file and let it rebuild a new one.

it could be that the simulator‘s physics engine thinks that your flaps are fully extended (I had this happen). Maybe due to misconfigured hardware. If you have for example - accidentally - assigned an axis to the yoke and to the flaps (or any axes have been assigned by P3D/FSX automatically) this could explain the loss of the autopilot and/or A/T. Before you resign please check that only those axes are assigned that you want to be and that none are assigned twice. Check all the controls in FSX/P3D. 

Don‘t set the elevator trim to a controller axis. 

If you use Active Sky (or any other addon wx engine) compare the turbulence settings to those that are adviced in the PMDG intro manual. 

The behaviour you describe is completely unnatural to the 737 and I think it‘s hardware or setup related and not airplane related in the first place.

Edited December 3, 2018 by Ephedrin