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