what kind of aircraft is used on the first class american airlines flight from philadelphia to san francisco stopping in dallas 
return flights ;return #1 in first class ;return #2 on  american airlines ;return #3 from  philadelphia ;return #4 to san francisco ;return #5 stopping in dallas ;return aircraft used in #6
['select', 'filter', 'filter', 'filter', 'filter', 'filter', 'project']