I need help understanding weight and balance on the 727-100.  

No matter what I do I can’t get the CG aft of station 9 in the FSX “Fuel and Payload” window.   Maybe I am confused about that display.  My understanding is that the forward heavy red line at Station 9 is the maximum allowable forward extent of the CG for the particular aircraft.   Likewise, the aft most heavy red line at Station 18 is the aft limit of CG for that AC.

When the 727-100 has no passengers, 31,400# fuel, and three crew;  the CG is between Stations 7 – 8 which is, to my understanding, about 6’ fwd of the max allowable fwd CG.  

If I load a 737-300 or a CS 757-200F with a CG that far forward they both visibly tip onto their front landing gear,

I use ACE to load 20,000 pounds in the aft two cargo slots and 4,140# of PAX in the aft most four rows. With that rather unusual load I find the CG just aft of Station 9 – still at what I thought was the forward most allowable CG.

When I use ACE to put on a typical load, 78 PAX, the first four 1st Class rows full, and the rest trying to find empty center seats, with 6,000# cargo in the aft four most container slots, the CG is again between stations 7-8 or at least 9’ forward of the forward limit for the AC.

I know a weight and balance sheet for the 727-100 shows the takeoff limits( at less than 142,000#)  to be 13% - 42%  of MAC and “economy” range is 28 – 33%.

I can not load the AC in order to move the CG to a safe position.  Do I misunderstand the CG display in Fuel and Payload?