Pirates of the Sky (1926)

Manning is engaged by the secret police to trail aeroplane thieves,who learn this and grab his ex-fiancée. Both escape from a burning cliff-building, and the gang leader "falls for" Doris, whom he does not suspect until a note to Manning (now disguised as an air mechanic) is intercepted. Manning rescues Doris, chases the mail by motor-cycle, climbs up into it, transfers to another, drops on to some hay, and after a revolver battle captures the crooks, the leader being later arrested; Doris comes to Manning's arms.