Autopilot disengaging uncommanded

[george]

Any suggestions as to why autopilot won't engage?

[JonathanBleeker]

The 3 SAS switches on? Within pitch/bank limits?

Oh the humor of your handle and the subject of this post....

[george]

Hi JB,

All SAS switches are on, acft well within flight envelope including speeds. Checked circuit breakers, etc. I think it may be a bug. I also noticed that the Tacan setting from a previous flight remains; in the past the Tacan setting would go back to original setting within the sim.

Years of fighter and commerical aircraft maintenance training and flight engineering taught me that typically autopilot disengages when manual input is sensed beyond throw pressure limits of the stick.

With SAS engaged to your point, the aircraft is supposed to hold an attitude given a certain stick input. If it were a real aircraft, and given the F-4, I'd sense it may be stray voltage, stick sensor or a bad CADC. I've seen a real F-4 eject three external tanks on the pad after the pilot turned on the generators. Ever seen a pilots eyes through his sun visor when that happens, ha ha!?


As for my handle, it has nothing to do with George AFB although I did work on Phantoms back in the day. Ha ha!

That handle was given to me by my parents, but I do see the humor.

Thanks for the quick reply.

Cheers,

George

F-16A/B/C/D, F-4G Phixer-C-141B Flight Engineer, 737NG Instructor.

[JonathanBleeker]

Does the AP Master switch flick back to the off position immediately after clicking it?

And no the humour is more how autopilots are often nicknamed "George".

[george]

Exactly, the switch cycles back. Have you seen that before?

[george]

First I've heard of autopilot being named George; I guess my folks must have had a vision for me, ha ha!

[JonathanBleeker]

Do you have it assigned to a joystick button in the MVAMS?

[george]

I do.

[JonathanBleeker]

Is toggle enabled on it?

[george]

That must have been it. I enabled toggle and it works. Thanks JB; well done.

Cheers

George

[JonathanBleeker]

Yup. If toggle is disabled it sets the AP to the state of the button. Useful if you have a physical switch that isn’t spring loaded.