When I select MMMX in the FSX menu, there are a lot of parking positions for "Heavy"; this all should be OK for a 767. Why GSX offers no parking position for me?
The "Heavy" designation is just a label. What counts is the parking radius set in the scenery AFCAD. If that is smaller than half of your wingspan, GSX will consider that parking to be too small.
Have a look at the GSX manual when the Airport customization is discussed ( Page 22 ), you can specify the "Max allowed wingspan" for each parking spot (or a group of parking spots, if more than one has been selected), which is the threshold for GSX to issue the "parking too small" message. The little button with the airplane icon on it, will automatically set to the minium value for the currently selected airplane.
