The hero
Oh yes, there is a backstory. From the original game manual:
“You are Max Chatsworth. Known by your mates as ‘The Blue Max’ you wear the very name of the medal given by the Axis powers to shoot down your plane! Now, you must earn the title. To be successful you must make a final assault on three specially marked targets within the city. You have only one aircraft and very little time to accomplish this most difficult of missions.”