Annoying warning

[Steven 1]

Hi guys,

 

I'm enjoying the PMDG 737 NGX since the first hour. But since a few flights I got a very annoying problem. When I'm crusing everything is fine, until some sounds makes a annoying 'beep-beep-beep' sound. I checked everything and I think the best I can do is post pictures of it:

 

This is a picture of the upper overhead. My master caution panel says in orange: OVERHEAD

 

Then, when I cut the sound off by clicking on the ALT HORN cutout (http://www.b737.org..../dcpcspanel.jpg) everything seems fine, except the PASS OXY ON warning on the first picture.

 

After several minutes the same 'warning' happens, only this time without sound (because I ignored it last time). This time, my master caution panel says:

 

and my presurrisation changed into this (AUTO FAIL):

 

So it has something to do with presurrisation. I hope someone can tell me exactly the problem, and how I can avoid it in the future.

 

Regards,

[mgardiner 4]

If your passenger oxygen is on, then you've had a de-pressurisation midflight.

 

Either that or you didn't set the relevant panel correctly. By any chance did you perform a "Packs Off" takeoff and forget to turn the packs back on after departure?

[ACA034137 37]

You need to have your cruise altitude selected on the pressurization panel. Also, use engine bleed air for the pressurization during cruise, not the APU..

[Steven 1]

Ah, I understand. How is this possible, and how to avoid it?

 

Regards,

[rmusick 1]

You need to set your flight altitude and landing altitude before takeoff.

[Steven 1]

Yes I know, I already did that, but because of the auto fail it disappeared.

 

I see the problem, I used the APU BLEED instead of the ENGINE BLEED, I'm sure, because the problem did only 2 times occured in let's say 200flights.

 

Thanks guys,

[CONTAG 2]

Just look at your last picture... Engine Bleed are closed and I don't think you are using your APU to pressurize the aircraft. You have the cabin de-pressurized and therefore oxygen mask are deployed.

 

Try setting your pressurization system properly and you won't have any issues. Remember: ENG Bleeds ON, APU Bleed OFF, PACKS AUTO and ISOLATION VALVE AUTO

[Fabo 213]

This is the reason to do pressurization checks at passing ten thousand - so this will not happen :)

[BIGSKY 316]

And to think that a real life crew had this same issue, makes my skin crawl.

[Ralgh 43]

I just want to be clear on something because I've read this a reason for the cabin altitude horn. Failing to set cruise altitude WILL NOT cause th cabin altitude warning. The pressurization computer will not allow the cabin altitude to climb that high even if you don't set the cruise altitude. Barring a system failure If you get the cabin altitude warning you have set the bleeds or packs incorrectly.

[Kerlix 99]

Barring a system failure If you get the cabin altitude warning you have set the bleeds or packs incorrectly.

 

Engine bleeds on, or the trip will be very uncomfortable.