Insert takeoff/landings only if they not already exist
Insert takeoff/landings only if they not already exist

Meisterschueler/ogn-python,glidernet/ogn-python,glidernet/ogn-python,glidernet/ogn-python,Meisterschueler/ogn-python,Meisterschueler/ogn-python,glidernet/ogn-python,Meisterschueler/ogn-python