View Full Version : Differential Pressure bug?

11-07-2009, 03:06 PM
Hello all,

I'm having problems with the differential pressure gauge in PMSystems (never paid attention to it before interfacing the overhead servo gauges, now that that they work, it's pretty obvious).

If the airplane is sitting on the ground at any airport above sea level (for example, KSEA at 440ft amsl), the differential pressure needle starts slowly rising and doesn't stop until it's reached about 8 PSI. This happens even with the engines shut down, APU off, and of all things, the doors open.

Obviously in that case the differential pressure should be 0 (as it should be, or within 0.125 anyway, any time on the ground), but the climbing needle is a problem both on the hardware servo gauge as well as the gauge as shown in the PMSystems software (meaning the servo gauge is just going where PMSystems tells it to).

This doesn't happen at airports close to sea level (i.e. St. Maarten or other beach-side airports), but does at every airport over 300ft amsl that I've tried.

Has anyone else experienced this?


11-09-2009, 07:41 AM

We have the same.
Do you see it in pmsystems virtual OH, or on the needle gaguge connected?

11-09-2009, 10:49 AM
We have the same.
Do you see it in pmsystems virtual OH, or on the needle gaguge connected?

As mentioned, I see it on both.

Glad to hear at least I'm not the only one seeing this! :cool:

11-09-2009, 12:58 PM
I plan to visit our hangar this week, I'll investigate it deeper.

11-09-2009, 01:59 PM
I have the same problem. Would be great if someone can find a solution.


11-12-2009, 07:29 AM
Well, I've checked and ... there is no solution :)

I've checked and found that A/C system works strange on PM.
There is no air logics in the logic file, so the variable is filled by something else, may be hardcoded in the pmsystems.

What I can propose is to develop pressure (and also cabin temperature) logic in the file and try it.

11-12-2009, 09:13 AM

Last week I've spoked with the guy of Flight Illusion at the Fsweekend @ Lelystad.
He told me that Enrico and Jonathan will clear this bug in the near future.

Maybe you can clear this with them.

Best regards

Jan Geurtsen