Again and again there is uncertainty about the correct operation of the FMC. On the basis of a detailed explanation of our Colleague Peter Guth CFG007 (Condor-VA), who explains the operation of the FMC step by step, is tried, to shed some light on the subject. The instruction happens on the FMC of the PSS777pro from Phoenix. But the system of the FMC is available for all types on the market are uniform. Can therefore be used as a general introduction to the use of the FMC system. Even if some "buttons" do not work with some systems.