flutter-problems-at-a-fanStall-flutter range underflight conditions Surge limitIncreasing flight Mach numberOperating line formiddle performance Maximum Mach number Relative corrected mass throughflowPressure ratio in the fanRPM characteristic lineabout 10 cm Outlet edgeDynamicfatigue crackDamage to a rotorblade of the firstfan stageFlutter problems in the development phase of a fanfor a fighter aircraft engine.