I note that the N1 predictions for the GE engines are off by a percent or two when compared to the N1 commanded by the FMC. But just in case you or someone else does. My second question has to do with TOPCAT and I understand that you may not have any idea here. So my question is this: given what you know about PFPX, should I expect that the fuel burn would be as predicted under ideal circumstances? Or are there any known issues with fuel predictions in the final phase of the flight? Could be any number of factors here - weather, primarily, or unpredicted time spent at intermediate altitudes, the speed schedule in the descent, etc. However, in each case, the approach (starting at TOD and going until landing) took about 6000 more lbs of fuel than predicted by PFPX.
I'm using the latest version of your 747-400 passenger GE performance file for PFPX, and the agreement was really excellent throughout the whole cruise portion. Normally I can't finish a full 15-hour flight but I was able to do this a time or two in the last few weeks, and I noticed that PSX and PFPX were basically in full agreement about the fuel consumption enroute. Steve, I have two quick questions for you.įirst, I had the pleasure of flying some full long-haul flights in PSX recently.
