LL40


#1

I am watching aircraft come and go from the private airport LL40 but FlightAware says this is an "Unknow or Invalid " airport code. This is the former C18 Frankfort Airport in Illinois. Why is this showing as an Invalid airport?

airnav.com/airport/LL40


#2

Are the airplanes flying IFR? Only IFR aircraft will be tracked.
The FlightAware database still accepts C18 as a valid code, though it probably will not show current traffic who would probably be using the new, correct code.