Cheyenne Chief Pilot 829 Posted August 17, 2017 Share Posted August 17, 2017 "Descent mode: The cabin full descent schedule occurs when the airplane is in descent. Cabin altitude decreases at approximately 300 to 750 ft/min, to either landing elevation, or maximum differential, whichever is highest. When the landing elevation exceeds 8,000 feet, cabin altitude will be maintained at maximum differential, until the airplane descends, then the cabin altitude will rate up to the pre-selected landing elevation." So normally the cabin should not descend below landing elevation before landing mode has started - and probably not 4.000 ft below before touchdown ... Please login to display this image. Please login to display this image. Please login to display this image. Link to comment Share on other sites More sharing options...
Cheyenne Chief Pilot 829 Posted August 19, 2017 Author Share Posted August 19, 2017 Cross-checked and confirmed, with a time series table: https://flightx.net/index.php?thread/94132-aerosoft-crj-700-900x-veröffentlicht-fsx/&postID=970623#post970623 Link to comment Share on other sites More sharing options...
Aerosoft Aerosoft Team [Inactive Account] 51558 Posted August 21, 2017 Aerosoft Share Posted August 21, 2017 We'll have a look at this. Link to comment Share on other sites More sharing options...
OccamsRazor 1 Posted August 26, 2017 Share Posted August 26, 2017 I'm getting this also. Didn't know at the time if it was supposed to be that way or if it was an error. Link to comment Share on other sites More sharing options...
Aerosoft Aerosoft Team [Inactive Account] 51558 Posted August 26, 2017 Aerosoft Share Posted August 26, 2017 Strange as it sounds, we also do not know if this is a bug. We got tables that are exactly as it is now implemented, but we agree, it is damned weird and we'll try to find more information and might redo that system. Link to comment Share on other sites More sharing options...
Cheyenne Chief Pilot 829 Posted August 26, 2017 Author Share Posted August 26, 2017 3 hours ago, Mathijs Kok said: (...) We got tables that are exactly as it is now implemented, (...) The DA/AS manual introduces the table like this: "The following table shows typical cabin altitude in relation to the aircrafts(sic!) altitude." A RW CRJ document introduces the same table like this (accentuation is mine): "The pressurization system automatically maintains cabin pressure through all phases of flight. Typical values used in the cabin/flight altitude schedule during manual mode are as follows:" So the table actually serves as an indication, directed at pilots, for manual operation only. Automatic mode is different from manual mode. As per the RW document (accentuation is mine): "Descent mode: The cabin full descent schedule occurs when the airplane is in descent. Cabin altitude decreases at approximately 300 to 750 ft/min, to either landing elevation, or maximum differential, whichever is highest. When the landing elevation exceeds 8,000 feet, cabin altitude will be maintained at maximum differential, until the airplane descends, then the cabin altitude will rate up to the pre-selected landing elevation. Landing mode: The cabin altitude is driven below field elevation or the airplane is unpressurized. When the cabin is below field elevation, then the cabin is rated up at approximately 600 ft/min for 30 seconds, then the outflow valve is driven full open." The table for manual operation does not take landing elevation into account, the automatic mode does, though. The automatic mode in fact is pretty generic. It's almost the same (with slight variations only) for most commercial (read: pressurized) aircraft, like the B737, the A320, the Fokker 70/100, the ERJ etc. (And I !daresay! also the ATR 72-500 ) They all drive the cabin altitude down to landing elevation during descent and, just before landing, a bit below that (150-200 ft below ldg elev). Even the German Wikipedia article covers that and also explains why: https://de.wikipedia.org/wiki/Druckkabine#Druckverh.C3.A4ltnisse Should any more questions arise, pls. do not hesitate to ask Joshua (... how he modeled pressurization in the AS A32x ). Link to comment Share on other sites More sharing options...
Cheyenne Chief Pilot 829 Posted August 26, 2017 Author Share Posted August 26, 2017 For purposes of comparison - the excellent(!) Flight1 ATR 72-500 heading towards the same destination: At cruise FL a maximum pressure differential is maintained: Please login to display this image. During the descent the cabin also descends to landing elevation: Please login to display this image. Just before landing a small(!) pressure differential is achieved (cabin slightly(!) lower than the destination field - 200 ft ballpark no.): Please login to display this image. After touchdown the cabin depressurizes and reaches exactly field elevation: Please login to display this image. You're welcome! Link to comment Share on other sites More sharing options...
Cheyenne Chief Pilot 829 Posted August 27, 2017 Author Share Posted August 27, 2017 I'd suggest 150 ft below ldg elev, rather than 200 ft. Reason is, a CRJ-200 CBT mentions 150 ft explicitly. Couldn't find a precise reference for the -700/-900, unfortunately. CRJ-200 CBT, pressurization, part II (part II starts right with descent mode): Link to comment Share on other sites More sharing options...
Deputy Sheriffs The Dude 6537 Posted August 27, 2017 Deputy Sheriffs Share Posted August 27, 2017 Once a tester always a tester. Link to comment Share on other sites More sharing options...
Cheyenne Chief Pilot 829 Posted August 27, 2017 Author Share Posted August 27, 2017 31 minutes ago, The Dude said: Once a tester always a tester. I paid 40+ EUR to become one of those again. Just trying to secure my investment. On a side note: Do *NOT* ask Joshua about pressurization (and *NOT* about GPWS Flaps Conf3 mode, either - got no warning during that approach! ): Please login to display this image. Better ask Hans (or Florian) : Please login to display this image. Link to comment Share on other sites More sharing options...
Deputy Sheriffs The Dude 6537 Posted August 27, 2017 Deputy Sheriffs Share Posted August 27, 2017 Just now, Enter display name here said: I paid 40+ EUR to become one of those again. Just trying to secure my investment. lol Link to comment Share on other sites More sharing options...
Cheyenne Chief Pilot 829 Posted December 13, 2017 Author Share Posted December 13, 2017 Bumped to the top of the Aerosoft forum. Another customer report here: https://www.avsim.com/forums/topic/524514-looks-like-major-crj-update-released/?do=findComment&comment=3767385 Link to comment Share on other sites More sharing options...
Aerosoft Aerosoft Team [Inactive Account] 51558 Posted December 13, 2017 Aerosoft Share Posted December 13, 2017 But yet again, as far as our documents show our implementation is correct. I'll ask Hans to look into this when he got time. Link to comment Share on other sites More sharing options...
Cheyenne Chief Pilot 829 Posted December 13, 2017 Author Share Posted December 13, 2017 3 minutes ago, Mathijs Kok said: But yet again, as far as our documents show our implementation is correct. I'll ask Hans to look into this when he got time. Pls. see my post here: On behalf of Aerosoft and Digital Aviation, Frank already admitted defeat (my interpretation only): Link to comment Share on other sites More sharing options...
Developer Hans Hartmann 3694 Posted December 13, 2017 Developer Share Posted December 13, 2017 It's still on my list but didn't make the cut for today's update... Link to comment Share on other sites More sharing options...
Cheyenne Chief Pilot 829 Posted December 13, 2017 Author Share Posted December 13, 2017 Thanks for confirming, Hans. And I am aware that you made it crystal clear that LNAV has had priority over work on other systems. I fully support that. (But now that - fingers crossed - the LNAV issue is off your chest ... ) Link to comment Share on other sites More sharing options...
Cheyenne Chief Pilot 829 Posted February 27, 2018 Author Share Posted February 27, 2018 Implementation of the automatic mode has been announced for version 1.0.5 of the CRJ: So, will the TCAS RAs be next for implementation? Link to comment Share on other sites More sharing options...
Developer Hans Hartmann 3694 Posted March 1, 2018 Developer Share Posted March 1, 2018 On 27.2.2018 at 15:55, Cheyenne Chief Pilot sagte: So, will the TCAS RAs be next for implementation? It's pretty much at the top of the list now, but I need to refresh my knowledge about vectors in three-dimensional space before I start working on this. Link to comment Share on other sites More sharing options...
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