Hi everyone,First of all, let me be clear, the NGX is by far the best airliner addon I've ever seen for FSX.That being said, there is one major flaw, I think, is that it's really hard to find the BASIC DATA for those aircraft.I think that if you want to really enjoy an airliner of such complexity, you have to plan your flight carefully.It's been said several times on those forum that TOPCAT was recommended for perf calculations.Here comes my request to PMDG or anyone else who could help.Would it be possible to get a synthetic document or post in the forum summarizing the weight values you used for the NGX ?What I'd like is basically the values needed to configure a TOPCAT profile, and I can't find it anywhere for certain.(MTW,MTOW,DOW,MLW,MZFW,Max Payload and so on).Let me give an example:For the B737-800, in the FCOM, the Max Taxi Weight is given on page 55 as 70760kg.In the FMS, when I go to FS ACTIONS, PAYLOAD, it gives me 79200 kg. Not the same thing...I was able to find a post made by Dr VAOS ( ;) ) I think giving a link to that document:http://www.boeing.com/commercial/airports/acaps/737sec2.pdf, which on page 13, is giving 3 other values !I'm having a headache !I know those values differ according to the customer options and so on.What i'd like to know is what values PMDG used for the NGX.It's a pity because otherwise, the documentation is very comprehensive, it just lacks the basic.Regards to all and especially to the PMDG team who did a hell of a job.

I believe PMDG left it up to you to decide! I think they allow for max weights to be used, that way you can set your own weight limits based on a certain plane in real life. With the CLS DC10, I had to modify the aircraft .cfg file to represent Boeing documents because they severely limited fuel capacity and such compared to real life. But with PMDG you don't have to do that!

Charles, I beleive William is correct. PMDG used the maximum available weights supplied by Boeing so that you have some room to play around with. For most of the profiles that I put together for TOPCAT, here´s what I used for the 800s:Single class 174 seats:Cargo capacity: 19,695 kgFuel: 20,820 kgDOW: 41,405 kgMZFW: 61,868 kgMTOW: 78,458 kgMLW: 66,361For the two-class configuration, the only thing I did was increase DOW to 42,991 kg. I don´t remember why, but I remember researching about it, so there is some rw explanation.These numbers, like you said, are ailine specific and vary a bit in real life. It´s hard to get them down correctly. But I think if you´re within a couple hundred kg you´re good to go.I recently discovered that there´s a lot more to discovering the weights of the airplane than I previiously thought. For example, according to regulations the dry operatign aircraft of all passenger acft has to be re-evaluated evry now and then, and there are several tehniques to accomplish this. Perhaps this document will help you: http://www.smartcockpit.com/pdf/flightops/aerodynamics/9

Thanks guys !Very interesting posts. I think i'll give a try with your values, Victor. Your explanations seem quite logical indeed. But I still think that PMDG should make it a bit clearer. I don't think this fact is mentioned in the doc, but it's very interesting. I'm definitely not the only one with questions about this, I just saw someone askingthe same question 24hrs after me !So that could be great if PMDG could come up with a synthetic document. Anyway, thank you very much for your input !

Can I just mention that you should never actually be using the MAX of anything. You always use the lowest defining limit so say Boeing has said your airframes Max taxi weight is 70760kg. That is not go to stop the cargo guys from loading pallets of lead or the fuel guys filling her to the neck. Nor will it change your airlines SOP of 70000kg, the taxi way three limit of 65,000kg or the maintenace guy who says temporary max 60,000kg. You as pilot (and dispatcher) must ensure that the lowest limit is observed, not the highest.