Show all the fleet series?
select fleet_series from aircraft
Which aircrafts have been flied by pilot whose name is "Charles Oakley"?
select t2.fleet_series from pilot_record as t1 join aircraft as t2 on t1.aircraft_id = t2.aircraft_id join pilot as t3 on t1.pilot_id = t3.pilot_id where t3.pilot_name = "Charles Oakley"
What about the ones that have been flied by pilots younger than 34
select t2.fleet_series from pilot_record as t1 join aircraft as t2 on t1.aircraft_id = t2.aircraft_id join pilot as t3 on t1.pilot_id = t3.pilot_id where t3.age < 34