REF speeds and FD deleting with AP disengage

[Boeing_Driver 76]

Hello folks,

 

I've been noticing that occasionally, when I'm flying an approach like an ILS, that sometimes, when I disengage the autopilot, the REF speeds disappear and the Flight Director goes away.

I can re-engage the FD by hitting the approach button on the MCP, but I have to remember what the original REF speeds were.

 

Is this a bug with the PMDG 737 or does it reflect something real in the actual airplane?

 

Thanks,

Brian Nuss

[downscc 1,327]

I've never seen this happen. You imply that you disengage the A/P using the A/P Disconnect and NOT the disconnect bar on the MCP, but it'd help if you described exactly when and how you do this.

It is very routine to disconnect A/P on approach before decision altitude/height, so yeah something else is turning off the F/D and resetting the APPR REF page of the FMS.

[Boeing_Driver 76]

3 minutes ago, downscc said:

I've never seen this happen. You imply that you disengage the A/P using the A/P Disconnect and NOT the disconnect bar on the MCP, but it'd help if you described exactly when and how you do this.

It is very routine to disconnect A/P on approach before decision altitude/height, so yeah something else is turning off the F/D and resetting the APPR REF page of the FMS.

Exactly. Yes, I use the button on my yoke that is dedicated to AP disengage, not the button on the MCP panel.

It doesn't always happen, so I don't why it happens when I see it.

[downscc 1,327]

6 minutes ago, XLS_DRiver said:

It doesn't always happen, so I don't why it happens when I see it.

Keep track of the sequence of events leading up to it when it happens.  It's not normal, but it is not a known bug so we are looking for something in your procedures behind it.