private:
int  HaveAirport()
unit GetAirport()
int  GetAirportSlotPos(int& pX, int& pY, int& pZ)
int  IsInAirportSlotPos()
int  SetPlaneAirport(unit uAirport)
int  MustBackToAirportForRefuel()
int  HaveEnoughFuelToExecuteCommands()
void SetAllowPlaneStop(int bSet)