Hi - From what I can tell the actual variant modeled in PMDG is the basic MD-11 with the heavy takeoff option, presumably the PIP program. The question I have is, is it possible to emulate the MD-11ER that had the additional 3,000 gal fuel tank by adjusting the fuel tank sizes in the Aircraft.cfg files and then just not using all of the forward cargo to compensate? Or is their logic elsewhere in the program that will cause this to fail (like not actually being able to refuel those large tanks because the FMS uses separate logic)?ThanksAndrew

Hello Andrew,you pretty much nailed it I think.The interaction between the seperate parameters is rather complex with PMDG's aircraft.Increasing the capacity of the existing fuel tanks will cause a shift in Center of Gravity beyond the safe envelope. I believe you would need lot of cargo in the forward part of the aircraft to counteract this, if it is even possible. On the real MD-11ER the additional fuel tank was installed in the forward cargo hold if I remember correctly and I think it is not possible to emulate this by just editing the aircraft.cfg. A change in CG will most likely also affect all FMS calculations. You could always extend the range of your MD11 by adding fuel in mid-flight through the PMDG menu though.Not perfect, but a lot safer than messing with the config files.P.S.: Please remember to post under your full name as per PMDG forum rules. Thank you.