Jump to content

Sign in to follow this  
SoloPilot

Autopilot Master Switch Not Reengaging

Recommended Posts

I recently hit the "z" button on my keyboard in-flight, thus disengaging the autopilot. However, when I went to reengage the autopilot via the CMD switch, it would not reengage. I assume that there is some kind of system that is stopping me from reengaging the autopilot? How do I reengage it without resetting the flight?

Matthew Lewandowski


Matthew Lewandowski

yeEIP.gif

signature-dark.png

Share this post


Link to post
Share on other sites

Hi,

Is your Z key simulating the AP disconnect switch on the yoke of the AP disconnect bar on the MCP?

If the disconnect bar is in the lower position, you cannot engage the AP.

Also check that your controls are at neutral position and the aircraft trimmed. 
These are the two situations preventing the AP to be engaged that come to my mind.


Romain Roux

204800.pngACH1179.jpg

 

Avec l'avion, nous avons inventé la ligne droite.

St Exupéry, Terre des hommes.

Share this post


Link to post
Share on other sites

I recommend you assign the autopilot disconnect in the PMDG Options keycommands and use that. The engage autopilot and disengage autopilot should be two separate commands. Do not use the disconnect bar mentioned by Romain, it is only used in non normal cases.


Dan Downs KCRP

Share this post


Link to post
Share on other sites

The Z key is set to the FSX default toggle autopilot, so it serves the same function as hitting the AP master switch on the MCP. This has also happened before, when I was taking off once. I had set the autopilot CMD switch on, and then I took off using the auto takeoff thrust button located on the top of the thrust levers. I also had the same issue.


Matthew Lewandowski

yeEIP.gif

signature-dark.png

Share this post


Link to post
Share on other sites

As advised by Dan, you should assign the key to the AP disconnect switch in the key commands through the CDU.

As suspected, the Z default sim assignment must put the AP disconnect bar in the lower position hence the impossibility to reengage the AP.

12 minutes ago, SoloPilot said:

I had set the autopilot CMD switch on, and then I took off

Do you mean that you engage the AP on the ground before taking off? If ever it is possible this is not the correct procedure. The AP should be engaged only above 400ft AGL.


Romain Roux

204800.pngACH1179.jpg

 

Avec l'avion, nous avons inventé la ligne droite.

St Exupéry, Terre des hommes.

Share this post


Link to post
Share on other sites
2 hours ago, Budbud said:

Do you mean that you engage the AP on the ground before taking off? If ever it is possible this is not the correct procedure. The AP should be engaged only above 400ft AGL.

Yes, I did that. I learned that it wasn’t correct procedure, but still I couldn’t reengage the autopilot. Also, the AP disconnect bar is not in the lower position. 


Matthew Lewandowski

yeEIP.gif

signature-dark.png

Share this post


Link to post
Share on other sites

What exactly happens when you try to reengage the AP? What alert, display?

And what is displayed on the FMA for the active/armed modes?


Romain Roux

204800.pngACH1179.jpg

 

Avec l'avion, nous avons inventé la ligne droite.

St Exupéry, Terre des hommes.

Share this post


Link to post
Share on other sites
2 minutes ago, Budbud said:

What exactly happens when you try to reengage the AP? What alert, display?

And what is displayed on the FMA for the active/armed modes?

Nothing alerts when I try reengaging. It just doesn’t do anything when I click the CMD buttons. Nothing shows up on the FMA for “CMD Arm” like it should


Matthew Lewandowski

yeEIP.gif

signature-dark.png

Share this post


Link to post
Share on other sites

Can you post a screenshot of the MCP and PFD?


Romain Roux

204800.pngACH1179.jpg

 

Avec l'avion, nous avons inventé la ligne droite.

St Exupéry, Terre des hommes.

Share this post


Link to post
Share on other sites

Ok so I figured out that shutting off both FDs then turning them back on allows the autopilot to be armed again.


Matthew Lewandowski

yeEIP.gif

signature-dark.png

Share this post


Link to post
Share on other sites

I don't remember for the NGX but on the 747 an invalid pitch/roll mode may prevent the engagement of the AP. Recycling both FDs reset the AP modes so it may be the explanation. However in this case you should have the red alert autopilot on the EICAS along with the invalid mode struck through in yellow on the FMA.

Or maybe the default FSX autopilot assignement just messes up with the AP of the NGX. In any case, I would suggest not to use the Z key anymore in the NGX or delete the default assignement in the FSX controls and assign it to the AP disconnect switch in the key commands in the PMDG setup via the CDU.


Romain Roux

204800.pngACH1179.jpg

 

Avec l'avion, nous avons inventé la ligne droite.

St Exupéry, Terre des hommes.

Share this post


Link to post
Share on other sites
11 hours ago, Budbud said:

I don't remember for the NGX but on the 747 an invalid pitch/roll mode may prevent the engagement of the AP. Recycling both FDs reset the AP modes so it may be the explanation. However in this case you should have the red alert autopilot on the EICAS along with the invalid mode struck through in yellow on the FMA.

Or maybe the default FSX autopilot assignement just messes up with the AP of the NGX. In any case, I would suggest not to use the Z key anymore in the NGX or delete the default assignement in the FSX controls and assign it to the AP disconnect switch in the key commands in the PMDG setup via the CDU.

Yeah, that's what I figured. I just flew the NGX again, and I used the takeoff thrust button. I didn't arm the CMD switch on takeoff. When I retracted the gear with the G button, I also heard a click as if a switch flipped in the cockpit. I don't know what it was, but I continued on. I went to arm the autopilot CMD, and I had the same issue. I tried resetting the FDs, and that didn't work either. I'm stuck again without any solution.


Matthew Lewandowski

yeEIP.gif

signature-dark.png

Share this post


Link to post
Share on other sites

Hmmmm, sometimes when I try clicking the button repeatedly, the green indicator light flashes on for a fraction of a second. It's like it almost can come on, but it won't.


Matthew Lewandowski

yeEIP.gif

signature-dark.png

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
  • Donation Goals

    AVSIM's 2020 Fundraising Goal

    Donate to our annual general fundraising goal. This donation keeps our doors open and providing you service 24 x 7 x 365. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. We reset this goal every new year for the following year's goal.


    17%
    $4,420.00 of $25,000.00 Donate Now
×
×
  • Create New...