FSX Project Magenta APP Mode problem

[alessio]

Hi Pete,

I have the problem that the autopilot approach control sometimes instigate a climb even when the aircraft should be holding level or descending on the Glideslope. I know that this is a problem from FSX (because of statement by Jonathan Richardson).

I have seen in the FSUIPC4 History that you have made a fix.

FiddleAppAltForPM=Yes

I have configured this in the FSUIPC.ini.

But the problem is still here.

I have all software updated. The PM MCP is working with WideFS.

What can I do there now?

Thanks for any help!

Best Regards

Alessio

[Pete Dowson]

I have the problem that the autopilot approach control sometimes instigate a climb even when the aircraft should be holding level or descending on the Glideslope. I know that this is a problem from FSX (because of statement by Jonathan Richardson).

Yes, though I think Enrico made changes to fix it in the later versions of the MCP application (at least for the 737NG, which is what I use).

I have seen in the FSUIPC4 History that you have made a fix.

FiddleAppAltForPM=Yes

I have configured this in the FSUIPC.ini.

But the problem is still here.

Strange as that fixed it pretty well for me -- it now only happens if I engage APP mode too early (before levelling out and intercepting the glidepath from below) and too fast.

Are you sure you put the parameter in the correct section ([General])? -- don't simply add it to the end of the file.

What can I do there now?

The fiddle in FSUIPC was definitely to counter a very specific bug in PM's MCP program, which I'm pretty sure is fixed. I think you should check the exact conditions which are applying when you get this problem, because it may well just be that you are exceeding one or more of the conditions needed for a stable entry.

Of course, it also maybe due to incorrect AIRCRAFT.TXT parameters (those provided to the CDU for the aircraft you are using) or a bad aircraft model (i.e. the AIR or AIRCRAFT.CFG). I use the PMDG 737-700 from FS9, with no panel of course.

Otherwise I'm afraid it is over to PM support.

Regards

Pete

[alessio]

Hi Pete,

thanks for the quickly response and tips.

I will testing more.

Regards

Alessio

[cockbit]

Hi

I had this effect constantly in FSX.

I realized the hint of Pete to use the FS9 PMDG B737-700 (in June).

I flew nearly each day since then without any problem....and now...as of spirit hand ..no more chance to follow the glideslope !!?

Strangely. Absolutely no changes at the FSX or the PC or the MCP were made.

Only.. I flew yesterday a baron 58. Could that change unnoticed a parameter somewhere ?

Still is no official solution well-known?

Regards

[Pete Dowson]

Still is no official solution well-known?

As far as I am aware it is not still a "known problem", so no solution is being sought. It was a bug, for sure, but fixed a long time ago in PM updates.

Glideslope acquisition works okay here UNLESS I am too heavy for the speed, or too fast for the weight, or I'm not flying level when acquiring the GS. In those cases it can fail to acquire, for sure. I also do not even engage APP mode till both GS and LOC diamonds go solid. Prior to that I use VOR LOC.

Regards

Pete

[cockbit]

Hi Pete

Thank you for the rapid answer.

Bud ...

I always fly the same touch and go (LFSB Basel Mulhausen) with always the same parameters.

Localizer established. Speed 175 knots ... waiting for the movement of the Glideslopebug.. Glideslope alive and highlited.

I press APP...the intersection is reached ... now it happens... the flightdirector rises… the airplane also.. and follows subsequently the glideslope with a positive offset of approx. 800 feets while the GSbug stays completely down at the instrument.

It is to despairs. Nevertheless the last 4 months ran without problems. Which parameter could have changed?

Importantly: The error happens only with the HW-MCP!

Which variables must I read (via FSUIPC Logging) to receive closer information to the happening?

In the appendix a video (FS-Video) of the incident.

Regards

CockBIT

[Pete Dowson]

Which variables must I read (via FSUIPC Logging) to receive closer information to the happening?

Sorry, I don't know the insides of PM's autopilot to know which of the many possible FS variables he is following. For all I know he could be computing by dead reckoning (but that is most unlikely). You need an exchange with PM support.

Regards

Pete

[cockbit]

Sorry, I don't know the insides of PM's autopilot to know which of the many possible FS variables he is following. For all I know he could be computing by dead reckoning (but that is most unlikely). You need an exchange with PM support.

Regards

Pete

Hi Pete

Thanks for your employment.

PM knows the following :

Hi

Yes there are differences, but I am not sure that this resolves the problem. The PMDG FS9 model used in FSX will still get this problem – seen it many times. If there is any instability in the VS at the GS capture you can get a miss capture and the a/c will clmb. It is far less likely to happen if the VS is rock solid. This is why people ‘think’ they have solved the problem only to be caught out at some other time. This is a well known and well running issue that I thought the only solution was the fix via the ini file – if that does not work, I am uncertain what factor in the airfile really causes this – I have never found a specific factor, but for sure many FS9 models and FSX models alike will still get the problem I’m afraid. It is more a problem of PM and us not ever being able to find a fix for it due to the random nature of the error. But certainly MS changed the behaviour between FS9 and FSX.

Regards

Jonathan Richardson

That was it peoples.

Regards

CockBIT

[Pete Dowson]

PM knows the following

Sorry then. Have you tried an aircraft based on the FSX airliners instead? I was using one based on the PMDG 737NG for FS9 -- without this ILS problem -- but have recently changed to one based on the FSX 738. I've not flown a complete flight yet with it, though, as I am still re-calibrating the trim indicator scale on my quadrant.

Regards

Pete

[cockbit]

Sorry then. Have you tried an aircraft based on the FSX airliners instead? I was using one based on the PMDG 737NG for FS9 -- without this ILS problem -- but have recently changed to one based on the FSX 738. I've not flown a complete flight yet with it, though, as I am still re-calibrating the trim indicator scale on my quadrant.

Regards

Pete

First the problem was with FSX based airplanes.

Then I was also using one based on the PMDG 737NG for FS9 (your hint) -- without this ILS problem for four months.

But since yesterday the problem is again there without any change at the system. Strangely!

Sorry..What is FSX 738 called?

Regards

CockBIT

[Pete Dowson]

Sorry..What is FSX 738 called?

The default FSX 737-800. The variation I am about to try isn't much different as far as I know. I'm only checking it out on my set-up because during start-up the PMDG one needs the fuel cut-offs set to idle at around 19% N2 which is not right, it should be nearer 25%.

Pete