Disengage Vertical Speed on B744 Autopilot

[Jetstar2 1]

Ok, I have been flying PMDG's excellent Queen for a couple of months now and cannot for the life of me get V/S mode to disengage while on the ground with the autopilot off. Whether I'm taxiing for takeoff or after landing, it seems once I engage the V/S mode (vertical speed), I cannot disengage it. I can turn off everything else on the autopilot except for V/S. It's button stays lit and nothing I do seems to unlight it. I have read the dox and couldn't find the answer. Any suggestions? Robert Williamson

[Tabs 2,790]

Robert,Did you turn the flight director on and off? That should clear out the whole AFDS and MCP...

[cowpatz 243]

Further to Ryan's comment you need to turn BOTH Flight directors off then back on (if both FD's were on in the first place). This should get you back to the TOGA TOGA indication on the mode annunciator. I assume you are referring to FD commands and mode annunciations as opposed to the AP being engaged on the ground with VS selected. I am not sure how you would get into this situation but if it were possible then disconnect the autopilot.

[Jetstar2 1]

Hey thanks for the reply. Turning off both Flight Directors did the trick, thanks! Robert Williamson

[Check_Airman 3]

I didn't even know anything other than LNAV and VNAV could be armed on the ground.Paul

[Qavion 19]

"I didn't even know anything other than LNAV and VNAV could be armed on the ground."It is possible to arm and engage a number of different AP and F/D modes on the ground on the real B744. However, sometimes you can't go directly to a particular mode... you have to go through another mode. After selecting TO/TO, you can select things like V/S and HDG HOLD. Then you can arm G/S and LOC. Mode transition logic sometimes prohibits certain modes.Cheers.Q>