I'm in the process of redoing the system logic for the 747 and have a question.
What offset would you use to read the flap value?
As you know, the 747 uses the center fuel tank initially, assuming that it has greater than 16,000 pounds of fuel, for takeoff and initial climb. However, system logic turns off the crossfeed valves 2 & 3 when flaps are extended for takeoff (flaps 10 or 20) to feed engines 2 & 3 from Main 2 & 3.
I've tried to use offset OBDC, which according to Pete Dowson's documentation should be read/write but can't get it to initiate the change.
Any thoughts from the experts out there?
Cheers,
Jon