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amahran

Pressurization System Inconsistent?

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1) Which cabin rate is actually valid, 200 or 300 fpm?:

image.png.c593dd47bdbcf2d7e90a9156aec7a3da.png

 

2) Emergency depress is very ineffective.

 

3) When cabin rate manual is selected, the manual controls don't seem to do anything.

 

4) Doors open doesn't immediately depressurize the aircraft

 

5) There's no master warning for when the aircraft is over-underpressurized (i.e., delta P falls below -0.5 PSID)

 

6) EXTRA: This mess happened in the left primary display. I'm not sure what it's actually supposed to look like, but I think the text isn't supposed to overlap like that:

image.thumb.png.c7af11a5a8ee4369a727c9ab85c39177.png

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I have been having issues with the pressurization as well. Even though both packs are on, the cabin will ascend to above 14000ft. The aircraft will also not descend until the plane is on the ground (I'll be descending through 2300, and the cabin altitude will still read as 14000. When I try to switch the pressurization to manual descent, there is no effect.

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This may seem obvious but did you update your CRJ? I remember the cabin pressurization was a hot topic early this year that lead to a patch that I believe addressed it. 

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Yesterday, on a flight from EGHI to EDDL (FL320) the cabin altitude rose up to 14000ft and stayed there till after landing. I am seeing strange pressurization issues from time to time. Possibly these are related to switching off the packs before take off and switching them on again after take off.

 

Michael

 

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vor 3 Stunden , michael-t sagte:

Possibly these are related to switching off the packs before take off and switching them on again after take off.

 

I'll give that a go.

 

I didn't have any pressurization issues for a long time, but I never switch off the packs before takeoff. Is there any special reason why you do that? It's not the checklists, or at least not on the checklists that I have.

The checklists in DAVE (manufacturer data) mention that the Packs should be switched on after engine start, so while still on the ground.

CRJ_After_Start.PNG

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Can you tell me which airport your took off from (for the elevation) and at which altitude you switched on the Packs?

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Hans,

 

take off was from EGHI Southampton. Since the runway is rather short, I did a packs off take off (this habit stems from a Boeing 737 tutorial). After reducing thrust from TOGA to CLB detent, I switched packs on (somewhere below 3000ft).

 

Michael

 

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I want to add that the ECS diagnostic page shows the packs to be on, even though the cabin altitude doesn't change.

 

In my case, after take-off, the cabin altitude remains at the airport altitude and doesn't climb to 8000', and in my case I leave the packs on "AUTO" after engine shutdown through preflight, pre-start, after start, and take-off. I think michale's is the opposite, that the cabin isn't pressurizing.

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8 hours ago, amahran said:

I want to add that the ECS diagnostic page shows the packs to be on, even though the cabin altitude doesn't change.

 

In my case, after take-off, the cabin altitude remains at the airport altitude and doesn't climb to 8000', and in my case I leave the packs on "AUTO" after engine shutdown through preflight, pre-start, after start, and take-off. I think michale's is the opposite, that the cabin isn't pressurizing.

On the real aircraft, if departing from a low elevation airport, the cabin altitude won’t start climbing until the aircraft reaches about  20,000 feet. The cabin altitude only starts rising when the differential pressure between the inside and outside of the aircraft approaches 7 psi. Cabin altitude won’t reach 8000 feet until the aircraft is above FL370. (The exact altitude depends on actual outside air pressure - it can vary a bit when using real weather injection).

 

The indication as to whether the cabin is pressurizing or not is the delta P (psi) reading, not cabin altitude.

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I have a simmilar problem with DIFF PRESS...  

 

Departing from Tunis to Zurich.   Set 1420ft landing altitude.   Followed all procedures, but......had the DIFF PRESS msg again.    After reading this post and still climbing, i turned PACKs off, turned cabin alt to Zero and turned the system on but manually, and then automatic again.   Voilah!   System started to increase pressure until normal pressure differential at or below 8.6..... but then noticed cabin altitude continued to increase, passed amber and turned to red..... also pressure differential continued to drop down....so oxigen mask had to be deployed...    No response from manual controls in the overhead panel to solve this... If switched to aotu, continued the altitude increase.   If switched to manual, apparently stopped at that point, but did nothing more, no matter what i tried with the pressure controls...

 

rFdqgscaKzI7axVrFLVMPny5X2jRXtn9tRQxqFz0

 

So....  Following thread....

 

Happy Flying! 😎

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On 9/20/2019 at 7:03 PM, Raphael_Chacon said:

I have a simmilar problem with DIFF PRESS...  

 

Departing from Tunis to Zurich.   Set 1420ft landing altitude.   Followed all procedures, but......had the DIFF PRESS msg again.    After reading this post and still climbing, i turned PACKs off, turned cabin alt to Zero and turned the system on but manually, and then automatic again.   Voilah!   System started to increase pressure until normal pressure differential at or below 8.6..... but then noticed cabin altitude continued to increase, passed amber and turned to red..... also pressure differential continued to drop down....so oxigen mask had to be deployed...    No response from manual controls in the overhead panel to solve this... If switched to aotu, continued the altitude increase.   If switched to manual, apparently stopped at that point, but did nothing more, no matter what i tried with the pressure controls...

 

So....  Following thread....

 

Happy Flying! 😎

 

 

This sums up my experience with the pressurization issues as well.

 

It's difficult to document into a condensed step-by-step list because it's such an inconsistent and non-repeatable problem. I'm trying to see if it has to do with cycling the packs or Bleed Air switch on the ground, maybe that's confusing the ECS system?

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True, we need to test it a bit more to reproduce issues(thats a very good approach), but seems faulty so far...  I mean, basic setup, right?

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I made several flights with packs off during takeoff (switched them on between 2000 and 3000ft AGL) but had no problems. I didn't try bleed air yet but will do next.

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I might have found something. The auto pressurization system has a FLIGHT ABORT mode which activates under the following conditions:

- flight time is less than 10 minutes

- total climb is less than 6000ft

- the pressurization system is in CLIMB mode

- Vertical speed is below -1000

 

If this happens, the cabin outflow valve opens and the cabin pressure will equal pressure at the aircraft's altitude for the rest of the flight.

 

Is it possible that this happened to you? I just managed run into this situation after a highly professional takeoff attempt with a CRJ-1000 ( 😉 )in Lukla.

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On 10/8/2019 at 3:13 PM, Hans Hartmann said:

takeoff attempt with a CRJ-1000 ( 😉 )in Lukla.

Is this a hint for the next CRJ update 🤔

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On 10/8/2019 at 9:13 AM, Hans Hartmann said:

I might have found something. The auto pressurization system has a FLIGHT ABORT mode which activates under the following conditions:

- flight time is less than 10 minutes

- total climb is less than 6000ft

- the pressurization system is in CLIMB mode

- Vertical speed is below -1000

 

If this happens, the cabin outflow valve opens and the cabin pressure will equal pressure at the aircraft's altitude for the rest of the flight.

 

Is it possible that this happened to you? I just managed run into this situation after a highly professional takeoff attempt with a CRJ-1000 ( 😉 )in Lukla.

 

I don't think so in the case I'm seeing, the problem I have is that the cabin alt doesn't climb (i.e., cabin altitude remains at 0 feet, and the delta P keeps rising).

 

I haven't been able to recreate it yet.

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We will start testing the next update soon™. If you like, you can join the test then to see if the changes I made to the pressurization system fix the issue.

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On 10/14/2019 at 4:23 AM, Hans Hartmann said:

We will start testing the next update soon™. If you like, you can join the test then to see if the changes I made to the pressurization system fix the issue.

Sure, hit me up™!

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vor 9 Stunden , amahran sagte:

Sure, hit me up™!

Please send a forum PM with your simulator version and hardware configuration, so I don't forget you.

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It seems that the cause of my problems with pressurization were old flights saved in 2017. I will continue to test fly and if the problem returns will report back.

 

Michael

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