Originally Posted by
gipilot
Hey guys, I’m a 747 jockey and have a question about the Drag/FF correction factors in the init page on the Honeywell FMS. I know that the FF is the bias for the fuel flow but my question is the Drag factor. Is that data also used by the VNAV to calculate the correct path and speed?
When I was flying the LCF, which is the extreme case, the FMC was loaded with a drag factor of 2.9 and a fuel flow factor of 5.0. It was otherwise a stock FMC/software load. With those inputs the FMC, including VNAV, worked. More or less....
So "yes" would appear to be the answer to your question.