Show names for all aircraft with at least two flights.
SELECT T2.name FROM Flight AS T1 JOIN Aircraft AS T2 ON T1.aid  =  T2.aid GROUP BY T1.aid HAVING count(*)  >= 2
SELECT T2.name FROM Flight AS T1 JOIN Aircraft AS T2 ON T1.aid  =  T2.aid GROUP BY T1.aid HAVING count(*)  >= 2
[{'name': 'Airbus A340-300'}, {'name': 'Lockheed L1011'}]