I noticed some differences between the default values in Topcat for weight limits and the PMDG values. However just search Youtube (NGX topcat) and you will find a tutorial where the guy explains which valuest to use to match the PMDG. Everything in mine now agrees except the stab trim which never does. I have another related question though. In the PMDG FMC V1 and VR are always essentially the same value. I assumed that this was due to the FMC not accounting for runway length. I assumed that Topcat would do this. Although Topcat does appear to be accounting for runway length in the V speed calculation it still gives a V1 and VR about the same. I imagined that for a short runway that in order to stop safely after RTO that a much lower V1 speed than VR would be required. Hopefully someone can clarify this.

great question, i have noticed it to, so basically what you're saying is to add to the temperature so it will match the thrust that topcat calculated? thanks(:

I too would like to now how to get accurate calculations with topcat. Even though i am certain the weights in topcat match the ngx, I vant seem to get the right N1 calculations from topcat :)

I have noticed the very same inconsistency between the two. I did some simple tests under certain conditions and it looks to me that we should aim for N1, not assumed temperature. That is, if for example Topcat tells me assumed temperature of 40C should result in N1 of 89% i will go and find assumed temperature in the FMC that gives me N1 of 89%. There is usually 6C difference between Topcat and FMC for the same N1. Uh, i hope i'm clear ;)

Hi captains,you guys might have missed a topic i opened a couple of days/weeks ago. Check this out please :Take the time to watch the video carefully .http://www.youtube.com/watch?v=e5GgfGgzf8s&feature=g-upl&context=G236b032AUAAAAAAAAAA

Thanks bakaman, Just found it, and it really helped me.. My problem was though that i did not realise that the engine rating on the 700 in topcat is different from the NGX :) Witth the 800 i get n1 +- 0.1%

Thanks bakaman, Just found it, and it really helped me.. My problem was though that i did not realise that the engine rating on the 700 in topcat is different from the NGX :) Witth the 800 i get n1 +- 0.1%

Cool then! and yeah the 700 datas in topcoat are based on the 22k performance which is to-1 in the fmc.cheers

TOPCAT use is covered in Tutorial #2 btw...

TOPCAT use is covered in Tutorial #2 btw...

Now why am I not suprised about that Ryan? Is there enything in #2 that is'nt covered? :DI am getting the feeling it would be easier to post whats not covered :(

thanks!!!EDIT: oh and can someone confirm that the stb. trim, isn't accurate? thanks(:

Edited February 23, 201214 yr by Daniel choen

you guys might have missed a topic i opened a couple of days/weeks ago. Check this out please :

Good video overall! I think you're overcomplicating things a little bit with per pax weight calculations instead of simply using ZFW. Some small mistakes like always talking about headings instead of track or radials, turning on wheel well for no apparent reason etc.One thing that bothers me is how come Topcat gave you N1 settings within 0.1% error margin. Think i'll have to run another couple of tests under ISA conditions just to see for myself ;)

Edited February 23, 201214 yr by rdb

You should also be sure that the engine types are the same.

KyleTry to add Martinair PH-MCU MD-11F with PW engines to TOPCAT. It cannot be done. The engines on the plane look like PW and A/C IDENT pages says they are the PW4462 model so I would think they are PW engines. However, TOPCAT has only one engine type in the dropdown options and that is the GE CF6-80C2D1F. Maybe the specifications of the GE and PW are exactly the same. Maybe PMDG only modeled the GE engine and that is the reason it is the only engine option in TOPCAT. Anyway, it’s disconcerting.Also the cargo capacity in TOPCAT is lower that the capacity in the MD-11F Load Manager and the figure in TOPCAT can’t be changed and saved.Michael

Edited February 24, 201214 yr by pcubine

Michael,We were not allowed to distribute the performance data for the MD-11 - Boeing specifically prohibited it. The author of TOPCAT actually did his own data collection with our MD-11 in order to create the profile - he just chose to only do the GE variant. The PW engines are in fact different and that is modeled. There's just no data for them in TOPCAT.

Ryan, AFAIK Christian got a hold of MD11 performance data from somewhere, I suspect via Doug S. and it is the real data, not data collection with PMDG MD-11 (but I could be wrong).As far as TOPCAT and NGX use is considered, this has been repeated many times by me and others, on TOPCAT and PMDG forums:a) You can not use TOPCATs loading functionality with the NGX, neither for payload nor for fuel.:( You can use TOPCATs performance calculations with NGX 800 as is.c) You can use TOPCATs performance calculations with NGX 700, provided you substitute TO thrust in TOPCAT for TO-1 in NGX, and TO-1 in TOPCAT for TO-2 in NGX, TO-2 in TOPCAT can not be used.d) The Stab Trim disrepancy is caused by TOPCAT assuming a different load distribution than NGX loader uses. Use FMC numbers.

Michael,We were not allowed to distribute the performance data for the MD-11 - Boeing specifically prohibited it.

Ryan,I'm just curious here, but what was their reason for that? I've noticed a lot of other add-on developers dealt with similar policies(Feelthere and Embraer, for instance). What exactly was Boeing concerned about?

Ryan,I'm just curious here, but what was their reason for that? I've noticed a lot of other add-on developers dealt with similar policies(Feelthere and Embraer, for instance). What exactly was Boeing concerned about?

just my guess (really i don't know) maybe they thought that it will be used for real world aviation, just my guess(:

Ryan, AFAIK Christian got a hold of MD11 performance data from somewhere, I suspect via Doug S. and it is the real data, not data collection with PMDG MD-11 (but I could be wrong).As far as TOPCAT and NGX use is considered, this has been repeated many times by me and others, on TOPCAT and PMDG forums:a) You can not use TOPCATs loading functionality with the NGX, neither for payload nor for fuel. :( You can use TOPCATs performance calculations with NGX 800 as is.c) You can use TOPCATs performance calculations with NGX 700, provided you substitute TO thrust in TOPCAT for TO-1 in NGX, and TO-1 in TOPCAT for TO-2 in NGX, TO-2 in TOPCAT can not be used.d) The Stab Trim disrepancy is caused by TOPCAT assuming a different load distribution than NGX loader uses. Use FMC numbers.

thanks man(: cheers.

KyleTry to add Martinair PH-MCU MD-11F with PW engines to TOPCAT. It cannot be done. The engines on the plane look like PW and A/C IDENT pages says they are the PW4462 model so I would think they are PW engines. However, TOPCAT has only one engine type in the dropdown options and that is the GE CF6-80C2D1F. Maybe the specifications of the GE and PW are exactly the same. Maybe PMDG only modeled the GE engine and that is the reason it is the only engine option in TOPCAT. Anyway, it’s disconcerting.Also the cargo capacity in TOPCAT is lower that the capacity in the MD-11F Load Manager and the figure in TOPCAT can’t be changed and saved.Michael

Right, but this is the NGX forum and my answer was directly related to that aircraft. Furthermore, what TOPCAT chooses to include in their planner is completely up to them and not a PMDG issue. My answer was merely to indicate that as long as the weights and engine thrust types are the same, you'll get proper numbers.Basically (this is for everyone here):If engines put out 25,000 pounds of thrust, it doesn't matter what type they are, they'll push you forward with 25,000 pounds of force.If you then attach those to a 737 and try to push it forward when it weighs 120,000 pounds, it doesn't matter if it's PMDG's, iFly's, Ariane's, or the real one - you'll get the same numbers.In the order of physics, this calculation is pure thrust versus weight (FSX doesn't model aerodynamics enough to get into arguments about variations in the shapes of the models).

Edited February 26, 201214 yr by scandinavian13

Hey, i have done some ABC... and got the calculation right! but there's a different between the thrust before engine start and after engine start, should i consider the after or before engine start? thanks!(:

Huh?