What is the empty CG for the CRJ700/550?

[ManyPandas 3]

There seems to be no resource I can find that will specify the proper 'Empty CG Position %MAC' in the sim Weight and Balance page. What should I set it to?

[Puuhbear 114]

35%

[ManyPandas 3]

19 minutes ago, Puuhbear said:

35%

Solved!

[Crabby 28]

31 minutes ago, ManyPandas said:

There seems to be no resource I can find that will specify the proper 'Empty CG Position %MAC' in the sim Weight and Balance page. What should I set it to?

That's because "someone" didn't read page 11 of the super top secret Volume 1 Aircraft Operating Manual. If you ever see this rare document (the only people who have it are Aerosoft CRJ owners) there are even pretty pictures of what a properly set CG in the sim is.  I'll bet if you keep reading the documents you will find a bunch of information that has no seeming resource, except for the documents.  Keep this quiet and to your self though.  We don't want all the riff raff gaining important knowledge by actually reading them.

[Puuhbear 114]

vor 1 minute, Crabby sagte:

That's because "someone" didn't read page 11 of the super top secret Volume 1 Aircraft Operating Manual. If you ever see this rare document (the only people who have it are Aerosoft CRJ owners) there are even pretty pictures of what a properly set CG in the sim is.  I'll bet if you keep reading the documents you will find a bunch of information that has no seeming resource, except for the documents.  Keep this quiet and to your self though.  We don't want all the riff raff gaining important knowledge by actually reading them.

No need to be sarcastic…

[Crabby 28]

8 minutes ago, Puuhbear said:

No need to be sarcastic…

Oh, yes there was.  There most certainly was.  Not only the need but the opportunity.

[Puuhbear 114]

vor 2 Minuten, Crabby sagte:

Oh, yes there was.  There most certainly was.  Not only the need but the opportunity.

There is never need for sarcasm. Take a  break and calm down…

[Crabby 28]

3 hours ago, Puuhbear said:

There is never need for sarcasm. Take a  break and calm down…

Ahh here this may help.

Please login to display this image.

[zenit_swe 90]

8 hours ago, Crabby said:

That's because "someone" didn't read page 11 of the super top secret Volume 1 Aircraft Operating Manual. If you ever see this rare document (the only people who have it are Aerosoft CRJ owners) there are even pretty pictures of what a properly set CG in the sim is.  I'll bet if you keep reading the documents you will find a bunch of information that has no seeming resource, except for the documents.  Keep this quiet and to your self though.  We don't want all the riff raff gaining important knowledge by actually reading them.

Looking at that page (or actually page 9) I can't find "Empty CG Position %MAC", but perhaps it can be calculated somehow based on those numbers?

[SinusJayCee 38]

I'm wondering why you are dealing with the sim's wight and balance page anyway. I just use performance page of the EFB and assume that it sets all values for me correctly.

[Puuhbear 114]

vor 6 Minuten, SinusJayCee sagte:

I'm wondering why you are dealing with the sim's wight and balance page anyway. I just use performance page of the EFB and assume that it sets all values for me correctly.

because for this to behave correctly you need to set the CG position slider to 35% in the sim.

[SinusJayCee 38]

vor 12 Minuten, Puuhbear sagte:

because for this to behave correctly you need to set the CG position slider to 35% in the sim.

Thanks for information! I actually didn't know about that. Has this to be done before each flight or only once?

 

*edit*

Just found the corresponding part in the CRJ's manual. I must have missed that part

[zenit_swe 90]

Don't you have both Zero Fuel CG and current CG on the EFB?

[SinusJayCee 38]

The question was about empty CG, so without payload

[Crabby 28]

6 hours ago, zenit_swe said:

Looking at that page (or actually page 9) I can't find "Empty CG Position %MAC", but perhaps it can be calculated somehow based on those numbers?

Really?  In the documentation file named Vol1_Aircraft Operating Manual_Part-1.pdf you cannot see this big red arrow on page 11 (page 11 on my reader).  You can calculate it all you want, or just maybe, you can do what it says to do at the end of the big red arrow.  

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[SinusJayCee 38]

Just for clarification: Do I need to set the empty CG position to 35% or do I need to set the slider to the full right position as advised by the manual? Because setting it to fully right results in an empty CG of 52%.

 

Furthermore, the CG indicated by the wight and balance menu doesn't match the CG indicated by the EFB. For example, with a ZFW of 27600kg and 4200kg fuel, the EFB shows a CG of 17.3%. To have the same CG in the weight and balance menu, the empty CG position needs to be set to 38%.

 

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*edit*

I did some additional experiments: Setting the empty CG position to 38% brings the CG reported by the weight and balance menu quite close to the values shown on the EFB for different combinations of passengers, FWD and AFT cargo, and fuel. Depending on the exact values, it may still be off by up to 0.5%, but that's the best compromise I was able to find.

 

 

[Crabby 28]

18 minutes ago, SinusJayCee said:

Just for clarification: Do I need to set the empty CG position to 35% or do I need to set the slider to the full right position as advised by the manual? Because setting it to fully right results in an empty CG of 52%.

 

Furthermore, the CG indicated by the wight and balance menu doesn't match the CG indicated by the EFB. For example, with a ZFW of 27600kg and 4200kg fuel, the EFB shows a CG of 17.3%. To have the same CG in the weight and balance menu, the empty CG position needs to be set to 38%.

 

Please login to display this image.

 

*edit*

I did some additional experiments: Setting the empty CG position to 38% brings the CG reported by the weight and balance menu quite close to the values shown on the EFB for different combinations of passengers, FWD and AFT cargo, and fuel. Depending on the exact values, it may still be off by up to 0.5%, but that's the best compromise I was able to find.

 

 

The manual is clear.  For proper EFB loading set the IN SIM to 35%.

Also, I learned a long time ago that how many passengers, where the cargo is etc is just a game of mental gymnastics.  Too many programs to try and sink up with passenger weights, baggage weights, are the passengers and bags combined and stuff like that.  In the real world pilots concern themselves with ZFW and fuel quantity (weight).  Dispatch handles the other stuff.  You never see a captain get up and go to the cabin and move people around or take a bag from forward cargo and put in in aft.  He is too busy calculating or inputting data to calculate take off speeds and other important stuff (cargo carriers may be different don't know).  So when I load I only load ZFW data and fuel.  In aircraft that allow it (like the Leonardo MD-80) I, at times, saw the need to adjust the COG (it loaded out of tolerance)  based on how the aircraft loaded and this was done with Fore and AFT adjustment button.  

 

In short, I have hundreds of hours on the MSFS CRJ.  I only load ZFW and Fuel weight on the EFB page you show above.  I always press the Set Payload in Sim button TWICE (sometimes I just click it a few times) and copy payload to the fms also twice.  I take note of the trim needed and I set the Vspeeds.  Done.  I never have issues with take off, climb, or cruise that can be attributed to the weight/balance. Only a small number of times, don't need a full hand to count, did I have any issues and it was attributable to either the in sim weather or Weather Force doing some funky things.  Weather Force seems to be stable and I can't even remember an issue.  

[GEK_the_Reaper 233]

vor 28 Minuten, SinusJayCee sagte:

ust for clarification: Do I need to set the empty CG position to 35% or do I need to set the slider to the full right position as advised by the manual? Because setting it to fully right results in an empty CG of 52%.

That seems to be another thing that changed with SU5.

 

Just don't touch it and leave it at default!

 

PS: It is called EMPTY CG POSITION so you don't have to change anything there (better...forget the Weight and Balance window in MSFS - all loading is done through the FMS)

[SinusJayCee 38]

vor 1 minute, Crabby sagte:

The manual is clear.  For proper EFB loading set the IN SIM to 35%.

In fact, the manual is clear in saying "Note that under Weight and Balance in this screen the indicated slider needs to be fully right."

 

vor 4 Minuten, Crabby sagte:

I always press the Set Payload in Sim button TWICE (sometimes I just click it a few times)

Yes, I noticed this as well.

 

vor 5 Minuten, GEK_the_Reaper sagte:

That seems to be another thing that changed with SU5.

 

Just don't touch it and leave it at default!

 

PS: It is called EMPTY CG POSITION so you don't have to change anything there (better...forget the Weight and Balance window in MSFS - all loading is done through the FMS)

I'm wondering whether this is something that got messed up with SU5 as well. Leaving it at default (which is 34.9% btw) resulting in a mismatch between the EFB and the W&B menu.And iIn the end, the CG indicated by the simulator is the one that is simulated with the flight model. So having a mismatch, the plane behaves differently than intended. In this particular case, it would be more nose have.

 

One can of course argue about the impact of this. The TO trim may be off of course. But that's not that bad in the end. But on the other hand, I'd like to have the simulation as accurate as possible.

[GEK_the_Reaper 233]

vor 1 minute, SinusJayCee sagte:

Leaving it at default (which is 34.9% btw) resulting in a mismatch between the EFB and the W&B menu.

Don't look at MSFS W&B screen! Just leave it as it is and load the CRJ through the EFB -please-.

[Herman 1591]

18 minutes ago, GEK_the_Reaper said:

That seems to be another thing that changed with SU5...

Maybe not. The need to mess with the empty CG setting may have changed a while ago and I just never relooked at it after first installing. There's a note in the Readme.txt file change log at update 2 that says, "- Correct CoG empty display in modified UI".

 

I do agree with the advice to leave it alone and at default.

[Crabby 28]

2 minutes ago, SinusJayCee said:

In fact, the manual is clear in saying "Note that under Weight and Balance in this screen the indicated slider needs to be fully right."

 

Ok, yes and some folks would stop there, but look at the picture.  Full right at the time is 35.  Set it at 35 or keep experimenting.  

[SinusJayCee 38]

vor 2 Minuten, GEK_the_Reaper sagte:

Don't look at MSFS W&B screen! Just leave it as it is and load the CRJ through the EFB -please-.

So the mismatch is actually intended and 35% is the value for the correct behavior of the plane? Then I'm fine with that and will ignore the W&B screen. I just wanted to clarify that this is no undiscovered bug and actually unintended

 

vor 3 Minuten, Crabby sagte:

Ok, yes and some folks would stop there, but look at the picture.  Full right at the time is 35.  Set it at 35 or keep experimenting.  

I got this. I was just pointing out that the manual isn't as clear as suggested by you Since 35% is also the default value and apparently the correct value, there is no need to mess with this anyway.

[zenit_swe 90]

13 hours ago, Crabby said:

Really?  In the documentation file named Vol1_Aircraft Operating Manual_Part-1.pdf you cannot see this big red arrow on page 11 (page 11 on my reader).  You can calculate it all you want, or just maybe, you can do what it says to do at the end of the big red arrow.  

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Sorry, missed that. I just assumed this number was presented in the tables with all the other weights and limitations. My bad.

[SinusJayCee 38]

Just FYI, I found an older comment by @JRBarrett stating that you should not even open the W&B manager:

Zitieren

It is best to not even open the MSFS default loading menu, as just opening it and then closing it (without making any changes) could potentially reset the CRJ CG to an invalid value, which could cause all sorts of performance issues when trying to fly. The CRJ was designed to be loaded only using the EFB.

 

 

However, I'm still wondering whether the empty CG value of 35% is still correct after SU5 due to the discrepancy even at the default load.