Question: Show the names of aircrafts that are associated with both an airport named "London Heathrow" and an airport named "London Gatwick"
SQL: SELECT T1.Aircraft FROM aircraft AS T1 JOIN airport_aircraft AS T2 ON T1.Aircraft_ID  =  T2.Aircraft_ID JOIN airport AS T3 ON T2.Airport_ID  =  T3.Airport_ID WHERE T3.Airport_Name  =  "London Heathrow" INTERSECT SELECT T1.Aircraft FROM aircraft AS T1 JOIN airport_aircraft AS T2 ON T1.Aircraft_ID  =  T2.Aircraft_ID JOIN airport AS T3 ON T2.Airport_ID  =  T3.Airport_ID WHERE T3.Airport_Name  =  "London Gatwick"