LRC always is about .84, LRC is not connected to any cost index and does not
care about any wind entered in the FMC. ECON CRZ takes the wind into account and will be around .83 when you get your planned/requested levels. Otherwise if you get stuck at a lower level it gradually would reduce speed to optimize your
fuel burn, however if you get your planned levels the difference between LRC and ECON will be about 5 to 7 min faster on a sector of 10 hours. If you select LRC over ECON, it will come at the expense of 100kg/ min you gain.
Last edited by mach 84; 15th Dec 2012 at 17:03.