Autoland problem with 737NGX (PMDG)

Skybird · 12-10-12, 08:05 PM

First, I know how an autoland should look like in theory and simulator practice - I have done it many, many times with this plane. My problem is not about missing something obvious, nor am I alone with it. I find descriptions of it in German and English forums alike, for example here:

http://forum.avsim.net/topic/362091-...-not-engaging/

Posting #17 bei lollo 883 is an exact description of my problem:

I approach the airport either in LNAV or HDG AP mode, and when I am close to the localiser, I press LOC (with CMD A active). I intercept the localizer successfully, and bring the plane into landing configuration. when the GS indicator starts moving, I press APP and it gets armed. At some time later, I need to switch on the second AP, of course, so I press CMD B.

In the past, this worked, and I did a nice and smooth dual channel autoland. But since I reinstalled my whole system two months ago and reinstalled FSX and 737NGX, I have not flown, and tried mky first flight this weekend (two flights), and today. And it suddenly does not work anymore:

Instead of having two APs on (CMD A and CMD B), CMD B lights for a few seconds together with CMD A - and then CMD A goes off, leaving me with CMD B. I then can switch baxck to A, and the the thing repeats itself. I have a single channel warning on the display as well.

Nevertheless, although it is single channel only, the plane nevertheless lands automatically, and flares nicely - with one AP only. Sometimes the APP light turns grey.

I have the Collins system instead og Hioneywell, and the digital standyby instruments. Manual says this is preocndition for the procedure working as intended.

All this has worked in the past. No new patches since then. Then system reinstall, and suddenly it does not work anymore? Some people report it is like this for them since the release of the software, since all beginning, and in all three service packs there have been so far.

Any advice?

It seems PMDG does not comment at all on this, I found nothing from them at least. To me, something smells buggy there.

I am not aware that I have changed my working procedures in any way. What has worked until system reinstallation, now does not work anymore. The result is successful, but the technical way there looks erratic.

Skybird · 12-11-12, 10:57 AM

Strange. Justz flew the same approach to EDDS, RW 29, like yesterday. a 800 with winglets, same aircraft and display setup but a different livery. Same flight, same procedure. I almost identically copied the working steps from 30nm to airport on. This time the AP worked as intended: both CMDs on and remained on.

If the aircraft setup configuration files would be different, then I would think there lies a small detail causing the difference. But they are identical. The PMDG-default skin, Air Berlin, for the 800 WL, sees effects like described yesterday. The foreign skin for a fictional Lufthansa that I now used, saw the AP working as I would expect.

Strange.

Played around with the FSX key command files, to solve the braking issue, but to no solution. Before takeoff, brakes did not work on the gorund, only the mnaual parkling brake, or releasing it via keyboard command. After landing, wheelbrakes suddenly worked as expected.

12-11-12, 10:57 AM	#2
Skybird Soaring Join Date: Sep 2001 Location: the mental asylum named Germany Posts: 40,461 Downloads: 9 Uploads: 0	Strange. Justz flew the same approach to EDDS, RW 29, like yesterday. a 800 with winglets, same aircraft and display setup but a different livery. Same flight, same procedure. I almost identically copied the working steps from 30nm to airport on. This time the AP worked as intended: both CMDs on and remained on. If the aircraft setup configuration files would be different, then I would think there lies a small detail causing the difference. But they are identical. The PMDG-default skin, Air Berlin, for the 800 WL, sees effects like described yesterday. The foreign skin for a fictional Lufthansa that I now used, saw the AP working as I would expect. Strange. Played around with the FSX key command files, to solve the braking issue, but to no solution. Before takeoff, brakes did not work on the gorund, only the mnaual parkling brake, or releasing it via keyboard command. After landing, wheelbrakes suddenly worked as expected. __________________ If you feel nuts, consult an expert.

12-10-12, 08:05 PM	#1
Skybird Soaring Join Date: Sep 2001 Location: the mental asylum named Germany Posts: 40,461 Downloads: 9 Uploads: 0	Autoland problem with 737NGX (PMDG) First, I know how an autoland should look like in theory and simulator practice - I have done it many, many times with this plane. My problem is not about missing something obvious, nor am I alone with it. I find descriptions of it in German and English forums alike, for example here: http://forum.avsim.net/topic/362091-...-not-engaging/ Posting #17 bei lollo 883 is an exact description of my problem: I approach the airport either in LNAV or HDG AP mode, and when I am close to the localiser, I press LOC (with CMD A active). I intercept the localizer successfully, and bring the plane into landing configuration. when the GS indicator starts moving, I press APP and it gets armed. At some time later, I need to switch on the second AP, of course, so I press CMD B. In the past, this worked, and I did a nice and smooth dual channel autoland. But since I reinstalled my whole system two months ago and reinstalled FSX and 737NGX, I have not flown, and tried mky first flight this weekend (two flights), and today. And it suddenly does not work anymore: Instead of having two APs on (CMD A and CMD B), CMD B lights for a few seconds together with CMD A - and then CMD A goes off, leaving me with CMD B. I then can switch baxck to A, and the the thing repeats itself. I have a single channel warning on the display as well. Nevertheless, although it is single channel only, the plane nevertheless lands automatically, and flares nicely - with one AP only. Sometimes the APP light turns grey. I have the Collins system instead og Hioneywell, and the digital standyby instruments. Manual says this is preocndition for the procedure working as intended. All this has worked in the past. No new patches since then. Then system reinstall, and suddenly it does not work anymore? Some people report it is like this for them since the release of the software, since all beginning, and in all three service packs there have been so far. Any advice? It seems PMDG does not comment at all on this, I found nothing from them at least. To me, something smells buggy there. I am not aware that I have changed my working procedures in any way. What has worked until system reinstallation, now does not work anymore. The result is successful, but the technical way there looks erratic. __________________ If you feel nuts, consult an expert.