NGX Auto Fail

[Sponge 74]

Last couple of flights i am getting auto fails on the cab press system.

- Failures are off.

- I am using AS201

- I cyled through all the Bleed and other switches. tried ALTN, nothing works.

- Alt is 38000ft. TAT is -22. SAT is -51.

- Winds are 307 at 18kts.

- Here is an overhead screenshot:

 

http://gyazo.com/e8c529709e71185eeb4e2a4658881854

 

I am literally baffled and have no clue anymore.

Flying this bird for over a year without issue's and all of a sudden the last couple of flight this is happening every single time.

[Yosm 19]

You may have forgotten to set the cabin alt before flight. it should have been at 38000 ft. when cruising at that level.

 

RGS, 

 

Yori Smulders

[Sponge 74]

Cabin alt and was set for 38000 
 

[scandinavian13 5,192]

Disregard...

[KriVa 307]

Some problems with this screenshot:

- The cabin altitude in the screenshot above shows +/- 38000ft.... At which point, your passengers would have about 20-25 seconds of useful consciousness.

- AUTO FAIL will light up whenever the Cabin Altitude passes 15800ft, which is obviously the case here.

- The differential pressure in your screenshot is 0 PSI. At FL380, you should close to the maximum differential pressure of 9PSI.

- The outflow valve seems to be rather far open, try switching the pressure controller to manual, close the outflow valve, packs in high and have a look if the cabin altitude descends.

 

Also, just to use correct wording: you don't set the cabin altitude AT 38000ft, you set it FOR 38000ft. There's a rather big difference, not the least in comfort level.

[davierosoft 13]

I already tried to post yesterday but seems that the forum with IE10 keep reset the page on each minute so I wrote 3 times the post and each time I was unable to complete it.

Now I'm using opera and I hope it will work.

Ok, back to the problem.

No problems on the overhead switches, all seems ok in the gauges except for the fact that the aircraft is completely unpressurized.

It is also normal that AUTO FAIL is on in that condition as the controller will tell to the pilots "hey, I'm not able to pressurize the plane, please do something"

 

Now, if there are no active failures I think it is a corrupted saved flight problem.

But you can also try if setting it to manual it will solve (so seeing if the logic works)

You can also see how it is working on climb. After take off check the outflow valve position, see if it changes, check if the controller works or it is fully locked.

[E6BAV8R 88]

After about 70 hours in the NGX of not having this issue I've now started to have the same problem of the 'Auto Fail' light coming on between 25,000 - 30,000ft.  My last 4 flights have all had the exact same problem, and also when the 'Auto Fail' light illuminates the autopilot becomes unresponsive.  I've followed the QRH and ALTN mode does nothing and I've then got to adjust the cabin altitude manually.  I still haven't yet had a fix for the autopilot, as I will disengage it and CMD will engage again but it will not follow MCP or F/D commands.  My guess is that some kind of autopilot hydraulic controller is getting sheared somehow - that would explain it engaging and not following any commands.

 

I've tried the flights with failures on and off and it made no difference - same result in consecutive flights.  I've also tried different liveries.  I've been starting the flights from the PMDG "Quick Turn" panel state and the only other thing I can think to try at this point is starting from a different panel state to see if the "Quick Turn" panel state is corrupted somehow (and how it could all of a sudden become corrupted after many hours is beyond me).

[scandinavian13 5,192]

 

 

I still haven't yet had a fix for the autopilot, as I will disengage it and CMD will engage again but it will not follow MCP or F/D commands.  My guess is that some kind of autopilot hydraulic controller is getting sheared somehow - that would explain it engaging and not following any commands.

 

Search the intro manual for "shear pin" ...

[E6BAV8R 88]

Search the intro manual for "shear pin" ...

 

Right, but this doesn't fully address the problem (unless I am misunderstanding).  Mainly:

1. If operating on CMD A at that time than only CMD A FCC would be sheared - meaning CMD B should still function (which it does not).
2. The associated CMD A will re-engage for me - it just doesnt' follow any F/D commands (this could be correct depending on what "re-engage" they are referring to in the document - either CMD re-engage or actual FCC re-engage).
3. If, in the manual, when it says "The associated autopilot cannot be re-engaged" is referring to the entire autopilot (both CMD A and B and not just the particular FCC associated with that particular CMD that was under operation at that time).

Also, here is a video showcasing a very close replica of what I'm experiencing, although my AP commands are much more accentuated than that.  Primarily, once the light comes on, the autopilot pitches forward to descend and then starts overspeeding. I didn't make the video.

 

[willywonka 36]

After about 70 hours in the NGX of not having this issue I've now started to have the same problem of the 'Auto Fail' light coming on between 25,000 - 30,000ft.  My last 4 flights have all had the exact same problem, and also when the 'Auto Fail' light illuminates the autopilot becomes unresponsive.  I've followed the QRH and ALTN mode does nothing and I've then got to adjust the cabin altitude manually.  I still haven't yet had a fix for the autopilot, as I will disengage it and CMD will engage again but it will not follow MCP or F/D commands.  My guess is that some kind of autopilot hydraulic controller is getting sheared somehow - that would explain it engaging and not following any commands.

 

I've tried the flights with failures on and off and it made no difference - same result in consecutive flights.  I've also tried different liveries.  I've been starting the flights from the PMDG "Quick Turn" panel state and the only other thing I can think to try at this point is starting from a different panel state to see if the "Quick Turn" panel state is corrupted somehow (and how it could all of a sudden become corrupted after many hours is beyond me).

Was it behaving like this?

 

 

Symptoms include unresponsive pressurization and A/P not following F/D.

 

If so, this is an activation problem. In this case, my BIOS clock was failing and it screwed up the activation code. Replacing my motherboard solved it.

[E6BAV8R 88]

Was it behaving like this?

 

Symptoms include unresponsive pressurization and A/P not following F/D.

 

If so, this is an activation problem. In this case, my BIOS clock was failing and it screwed up the activation code. Replacing my motherboard solved it.

 

Pretty much, yes.

 

I'm actually very glad that you brought up the BIOS clock issue up.  My Windows Clock Time has actually been losing date and time, which typically means a motherboard CMOS battery is dying (which could lead to the activation issue you are referring to).  I'll go out and buy a new CMOS battery and see how it goes.

 

After replacing your motherboard did you need to re-install the NGX for it to start working properly again?

[willywonka 36]

Pretty much, yes.

 

I'm actually very glad that you brought up the BIOS clock issue up.  My Windows Clock Time has actually been losing date and time, which typically means a motherboard CMOS battery is dying (which could lead to the activation issue you are referring to).  I'll go out and buy a new CMOS battery and see how it goes.

 

After replacing your motherboard did you need to re-install the NGX for it to start working properly again?

Ha, I just saw that you even posted one of my videos to show the problem.

 

It could be the CMOS battery. I replaced mine but it didn't solve it, so I guess it really was the crystal. Anyway, replacing the board did fix the problem. And no, I didn't need to reinstall the NGX. It really was just the clock all along. 

[E6BAV8R 88]

Ha, I just saw that you even posted one of my videos to show the problem.

 

It could be the CMOS battery. I replaced mine but it didn't solve it, so I guess it really was the crystal. Anyway, replacing the board did fix the problem. And no, I didn't need to reinstall the NGX. It really was just the clock all along. 

 

I replaced my CMOS battery and that seems to have fixed everything.  Just did a 3.5 hour flight with no issues, so thanks for the info!  An extremely weird issue that I probably wouldn't have ever guessed that it messed with the PMDG aircraft.

[willywonka 36]

I replaced my CMOS battery and that seems to have fixed everything.  Just did a 3.5 hour flight with no issues, so thanks for the info!  An extremely weird issue that I probably wouldn't have ever guessed that it messed with the PMDG aircraft.

Yea, it's a weird one. When I emailed support they said that had never seen it before. I think they're aware of it now because I've seen this issue come up on the forum about once a month.

[Flamin_Squirrel 71]

Woah, that's just about the strangest fix I've ever heard. Piece of **** FSX really is the best stress test for a PC ever.