PNEUMATIC_SYSTEM_EX1 - Engine Bleed Air stops if Pack it turned off

[MSFS 2024] Bug Reports Aircraft
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1

Version: 1.6.7.

Frequency: Consistently

Severity: High

Context: [PNEUMATIC_SYSTEM_EX1]

Bug description:

Engine Bleed Air stops if Pack it turned off

Repro steps:

Create a simple pneumatic system:

Engine.1 = Name:Engine #Index:1 #Bleedtemperaturescurve:1 #Outputflow:1.15
Curve.1 = 0:25,100:70
Pack.1 = Name:AcPack #Circuit:1 #MinTemperatureOutput:10 #MaxTemperatureOutput:15 #TypicalFlow:1.15 #ManagedAreas:Cabin
Area.1 = Name:Cabin #Volume:3.42 #AmbientbleedStaticFlow:0.01
MixerUnit.1 = Name: Mixer
Valve.1 = Name:HotAirValve #Type:HotAir #ManagedArea:Cabin #PID:0.01, 0.001, 0.001
Valve.2 = Name:OutflowValve #Type:Outflow
Junction.1 = Name:BleedAirJunction #InputOnlyLines:EngineToBleedAirJunction #OutputOnlyLines:BleedAirJunctionToMixer, BleedAirJunctionToCabin
Line.1 = Name:EngineToBleedAirJunction #Source:Engine #Destination:BleedAirJunction
Line.2 = Name:BleedAirJunctionToMixer #Source:BleedAirJunction #Destination:Mixer #Valves:HotAirValve
Line.3 = Name:MixerToCabin #Source:Mixer #Destination:Cabin
Line.4 = Name:BleedAirJunctionToAcPack #Source:BleedAirJunction #Destination:AcPack
Line.4 = Name:AcPackToMixer #Source:AcPack #Destination:Mixer
Line.5 = Name:CabinToOutflowValve #Source:Cabin #Destination:OutflowValve

Create a simple pneumatic system with a pack.
Turn off the pack, and notice all engine bleed input stops shutting down every system connected.
Try to heat the cabin with the vale on the other other line, notice there is no air movement when the pack is off.

Attachments:

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1 Like
2

I also noticed that the moment we turn of the pack PNEUMATICS ENGINE BLEED AIR TEMPERATURE simvar value drops to 0 instantly.

1 Like
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Can I get a confirmation that this is a bug?

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Hello @CaptainBalu0

I think this is a configuration problem, as this does not occur with the 737.

I see several problem with the configuration you provided:

  • You have a duplicate Line.4, which leads to your pack not being connected to your mixer
  • Some missing parameters like AreasMinTemperature and AreasMaxTemperature lead to pneumatic system errors.

You can track such errors by selecting the Pneumatics group after loading your aircraft

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image445×474 36.8 KB

If you still have issues after addressing this, please provide us with a package demonstrating the problem.

Regards,
Sylvain

5

Sorry about the incorrect example, I just throw it together for the bug report I have a more complex system.
I tested with the 737 as well before reporting, and it presents the issue as well, you just need to be a bit tricky about it.
Use the debug window, to turn off the packs, and look at the lines, you have to wait a bit, but all airflow from the engines will stop if all packs are off.

I will test again tonight with both my aircraft and the 737 as well.

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Ok I think I see what you mean, it works for a moment but the pressure continuously drops and eventually reaches ambient pressure.

I’ll have that reviewed.

Regards,
Sylvain

3 Likes
7

Yes , exactly. Thanks for the follow up.

1 Like
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This is now affecting one of my products, it uses 1 PACK only, the PACK can be OFF via a cabin switch while the rest of the HOT AIR Bleed system should continue to service anti-ice systems, etc.

Any idea of when this is planned to be addresed?

Best,

Raul

1 Like