Task: Text to Code
Input (English): Step 1: find the DestAirport of flights table.
Step 2: find the AirportName of airports table whose AirportCode not one of the results of step 1
Output (English): SELECT T1.AirportName FROM airports AS T1 WHERE T1.AirportCode NOT IN ( SELECT T2.DestAirport FROM flights AS T2 )