When you ask GSX Level 2 to perform re-fueling, the advisory message appeared: 'Please use the refueling system of your aircraft to refuel'
That's exactly what GSX is supposed to ask here.
What is suppose to happen here? Shouldn't GSX ask how much you want to re-fuel, eg. 65% etc ..?
Quoting from the GSX manual, Page 19, which has an example using precisely the PMDG-777, to clearly explain what you are supposed to do when an airplane is flagged as having a custom Fuel System.
A 3rd party airplane with a Progressive Refueling simulation, the PMDG 777:• Start by selecting an initial Fuel Quantity, using the “FUEL” option in the “FS ACTIONS” menu on the FMC. This will immediately set the desired Fuel Quantity to start with.
• Select the “GROUND OPERATIONS” from the “FS ACTIONS” menu on the FMC, and choose one of the “TURN TIPE” options, SHORT/LONG/MANUAL.
• Insert the planned Fuel quantity in the “PLAN FUEL” field on the same page.
• According to how PMDG simulated the Turn-around, the refueling will start in about 5 minutes, so you should call the GSX Refueling now.
• When the Fuel Truck arrives, it will wait for the progressive refueling simulation in the PMDG to start, in order to start its own fuel counters.
• The refueling speed will be controlled by the airplane.
• The Fuel Truck will stay until the PMDG has finished loading fuel, or the Truck itself is full, and another truck will eventually arrive, if the “Multiple Trips” option is enabled in the GSX Settings.
Now, I haven't seen the new PMDG 777-200ER, so I'm not sure the wording on the FMC is exactly as it was in the previous version but, the concept is the same, when an airplane has a custom fuel system, GSX will NEVER ask you for the fuel quantity and, if the airplane also has a progressive refueling feature, you must call the GSX refueling only AFTER you PLANNED a refueling ( which will start sometime ) with the airplane system, so GSX will wait for the airplane own refueling to start, to adapt its own fuel counters to it, and wait for the refueling process to end, to know when it's time to go away.
The main basic concept is: if the airplane is flagged as having a custom refueling system ( and all PMDG surely are ), GSX will never actually "refuel" it, but it will adapt with its animations to whatever the airplane is doing to refuel itself, it will never try to change or act on the fuel quantity directly.
