Which airline does the aircraft with the fastest flight belong to?
fastest flight refers to MIN(SUBTRACT(ACTUAL_ELAPSED_TIME, CRS_ELAPSED_TIME));
SELECT T1.OP_CARRIER_AIRLINE_ID FROM Airlines AS T1 INNER JOIN Airports AS T2 ON T1.ORIGIN = T2.Code WHERE T1.ACTUAL_ELAPSED_TIME IS NOT NULL AND T1.CRS_ELAPSED_TIME IS NOT NULL ORDER BY T1.ACTUAL_ELAPSED_TIME - T1.CRS_ELAPSED_TIME ASC LIMIT 1