OK this is what Iam working on now I know this is long but hang in there .Igot to think this one out.
Parking Radius:
Each of the eleven standard parking types has a default radius (size). For example, "Ramp GA small" is 10 m (32.8 ft), "Gate Medium" is 38 m (124.7 ft), and so on. AFCAD will assign the default radius when you first create a parking spot, and you can keep that value or you can change it to any radius you want. You can also change the default radiuses (see Standard Parking Types).
The parking radius is normally used by FS2002 to direct various sized AI aircraft to the appropriate sized parking spot. An AI aircraft will park at the smallest empty parking spot that is big enough to hold that aircraft (they will park at bigger spots if none of the 'right sized' spots are available). The required parking spot radius for a particular model of aircraft is specified in the .mdl (model) file for that aircraft. That radius is typically 75% of the wingspan, rounded off to the nearest metre. This means you can make parking spots that are matches for most individual aircraft models (737, MD83 etc.) and get those models to park in only those spaces, unless they are all full. Here is a list of minimum parking sizes for some FS stock aircraft.
Dash8 15 m (50 ft)
737 22 m (73 ft)
MD83 24 m (79 ft)
747 47 m (155 ft)
777 46 m (151 ft)
Note that the parking radius appears to only be encoded in the .mdl files for FS2002-built aircraft (stock aircraft and GMAX-built aircraft). The parking radius is specified in the header of the .mdl file. Aircraft not built with GMAX, which includes virtually all older add-on aircraft, use a different type of .mdl file which does not have the parking radius encoded. For those aircraft, Flight Simulator applies a default parking radius of 16 metres (52.1 feet). This can result in many add-on aircraft parking in inappropriate sized spots. At this time there does not appear to be anything that can be done about this. Note that even some GMAX built aircraft can have the radius incorrectly encoded, but this can be fixed by modifying the .mdl file radius entry with one of the features of the following third party utility:
AITM by Thomas Molitor. Available at
www.molitor-home.de/fs/aitm/Parking List Window:
The Parking List window, called from the Lists menu, shows all the parking spots for the current airport as they will appear in the start locations list that you call from the Flight Simulator Create a Flight window, with the addition of the radius for each spot.
Parking Order:
Parking is assigned to AI aircraft in the order the parking spots appear in the Parking List window. When you start a flight at an airport, Flight Simulator will place the AI aircraft in the appropriately sized parking spots in sequence, down the list.
It may look more orderly to put all gates in the list in sequential order, for example Gate 1, Gate 2, Gate 3