Baron cabin controller scale off?

[Schmidde]

Hello,

i may noticed a discrepancy in the set aircraft altitude and resulting cabin alt and differential pressure.

In the picture below: Acft at FL140, on the cabin controller is set a target alt of 15000 ft ( i´ve given already a 1000 ft margin)

with this setting a get a "CABIN DIFF" warning because the cabin diff pressure is in the red and the cabin controller doesn´t know what to do, it fluctuates between climbing (maybe to reduce diff pressure) an descending because then the cabin alt goes over the set value of ~3000ft cabin alt.

I need 16000ft on the cabin controller to get in the green diff pressure range, with seems a little high to me for FL140? (i don´t know, i´m only a sim pilot with no connection to real world flying)

[Voice of Reason]

Reply direct from the developer for you:

The pressurization system is generally working correctly. When the cabin pressure differential exceeds limits, a dump valve is opened to release pressure before damaging the airframe, after which the cabin continues to descend again. It's possible that the performance is a little off, as I do recall making some changes right before release. Before then, the performance was actually a little "better" than indicated on the scale. I will investigate prior to the next update. Hope that helps for now.

[Voice of Reason]

More from the developer for you on this after some findings today...

I did some testing with this today. The pressurization system is working correctly to my knowledge. When you exceed the maximum cabin differential pressure, the pressurization controller does not simply limit the maximum differential, but will "bump" (as the manual calls it) the pressure relief valve open with hysteresis to reduce cabin pressure before descending once again. I slightly adjusted the altitude goal animation to give more precise numbers (I doubt the unit in the real aircraft is this precise, given my experience owning GA aircraft). Don't forget that the marking on the face of the instrument also makes the setting subject to parallax effects. I also found the pressure differential needle to read about 0.1 PSI high, which has now been corrected, but this would not affect the warning annunciators.

Cruising at 25,000 ft, I was able to maintain a cabin altitude of 12,500 ft with a pressure differential of 3.674 PSI, which matched on all the needles. At 25,000 ft, the maximum pressure differential of 3.9 PSI was achieved with a cabin altitude of 11,800 ft, which is slightly better performance than advertised. I had found similar results on a previous investigation for another customer. Keep in mind that the cabin pressurization scale depicts pressure altitude, not adjusted cruising altitude. This means that the altitudes advertised will only be exact on a perfectly standard temperature and pressure day.

If you would like the new settings for the pressure differential needle of a more accurate reading, please change the following values in the "CabinDifferentialPressureNeedle" Component of AnalogBaron.xml. This file is located at: [YourCommunityFolder]\bksq-aircraft-analogbaron\SimObjects\Airplanes\bksq-aircraft-analogbaron\model.base\

MAX_VALUE 7 --> 9
END_DEG 285 --> 360

Good luck, hope that works.