PMDG gives MTOW of the 737-700 as 133,000 pounds(Fuel Planning Schematic), Boeing as 154,500 pounds. Similar differences for the other models.What's the explanation, please?Boeing site here: http://www.boeing.com/commercial/737family...pf_700tech.htmlBR,Frank

Frank,Every operator "buy" a maximum structural take-off weight from Boeing. It's cheaper to get a -700 with a lower MTOW than with a higher ditto. I guess the reason here is that the NG the PMDG one is based on is bought with the MTOW 153,000 (not 122,000 right?) instead of Boeing's 154,500. I guess the latter figure is the max certified take-off weight for the -700. Scandinavian Airlines has a MTOW of 61,700 kgs (i.e. 136,025 lbs) for example.Below a statement from Scandinavian Airlines Flight Ops web site www.sasflightops.com:8<---Boeing sells its aircraft with different takeoff weights. This means the Boeing 737-600 can be purchased with a start weight of between 57 and 65 tons. SAS has up to now chosen a low start weight for its aircaft, the foundation being the destinations the aircraft are expected to traffic. With these start weights SAS can for example: fly the Stockholm-Geneva route with a full load."But the aircraft can, if we have the need, fly longer. It only concerns raising the permitted start weight, through a simple business transaction with Boeing. All bairplanes are identical and have the same fuel tank size - it only concerns the amount of fuel one can put in. But since the purchase price is founded on the start weight, the airline has to pay more if the airplane is going to be used on longer routes. One example is the airplanes performance, we can name that we have planned to fly the airplane nonstop Seattle-Stockholm", explains Stefan Neufeld.8<---Hope it helps,

Thanks, Mats. That does help."I guess the reason here is that the NG the PMDG one is based on is bought with the MTOW 153,000 (not 122,000 right?)"Well, the Fuel Planning Schematic for the -700 has 133,500 pounds for taxi out, which gives an MTOW of 133,000 pounds. The reason for my question was that I thought the difference of 21,500 pounds between the PMDG and Boeing figures was rather large?BR,Frank

Hi again, Mats.Just reading your mail again(at work, so have to read quickly!). Am I understanding Stefan Neufeld correctly that all -600s are exactly the same structural weight, but you get a more favorable price if you promise to limit the max fuel you put in?Thanks,Frank

Hi Frank,What version of the NG are you running? The V1.3 load manager has 144000 lbs for the -600 and 153500 lbs for the -700 as max takeoff weights.JohnBoeing 727/737 & Lockheed C-130/L-100 Mechanichttp://www.precisionmanuals.com/images/forum/ng_driver.jpg

Frank,What you limit is the structural MTOW and could be fuel and/or cargo/pax. The actual EOW (Empty Operating Weight) is still the same. If you limit your MTOW you get a more favourable price, yes. Strange but true. This is a strategical decision for the operator. Say they operate on short runways only. No need to go for the full structural limit weight price because the runway will always limit the weight anyway.Or they only plan to fly the NGs on trips which are short to mediumm distance. Thus they will never fill the tanks up. You don't need the full structural weights here either.Hope it helps,

Hi John,Yes, I noticed that tonight.I had been calculating weights and fuel manually, and was using the Fuel Planning Schematic for the -700, which appears in the PMDG AOM at 2-6(Cruise Flight). There it states that the Max Gross Takeoff Weight cannot be greater than 133,000 pounds, but this is obviously mistaken, as it would mean that, if you were envisging a Max Landing Weight of 128,000 pounds, you could only carry 5,000 pounds of fuel!!!In any case, both the Load Manager figures, and the technical specs I noticed on the PMDG site make it clear that the MTOW for the -700 is actually 153,500 pounds, which is just what Mr Boeing says!Thanks for your post.BR,FrankPS I also had another problem while doing my calculations, for which, see my post, Required Runway Takeoff Length. /F

I have noticed the Schematic Planned Gross takeoff Weight for the 700 is 133,000 lb and the Load Manager says maximum Takeoff Weight is 153,500lb. The Taxi out weight is in the Schematic is shown at 133,500lb. I would assume the Load Manager to be figure to use, is it not?

Yes, I'm quite sure the Fuel Planning Schematic is wrong.BR,Frank