Filmmakers attempted to use lightweight reproductions of WWI aircraft, but grounded them after an accident.
The first movie to motion capture planes.
As no studios would back the film, a group of filmmakers and investors including producer 'Dean Devlin (I)' and (according to press-releases) "ace pilot" David Ellison, son of Oracle Corp. founder Larry Ellison, spent more than $60 million of their own money to make and market this film.
The real Lafayette Escadrille actually had a pair of lion cubs as mascots. One was indeed named "Whiskey," as in the film. The other, appropriately enough, was named "Soda."
The personal insignia of Reed Cassidy is an eagle's head surrounded by the words "Je Vois Tout" meaning "I see all".
In the scene where the pilots are painting or having painted personalizations on the sides of their airplanes, Lyle Porter is painting a banner that reads "Timothy CH. IV V. 7". This is reference to a chapter and verse in the Book of Timothy in the Bible. There are TWO books of Timothy in the Bible, both having a chapter IV and verse 7. However, more than likely, this would be a reference to the SECOND book of Timothy, chapter IV, verse 7, which reads, "I have fought a good fight, I have finished my course, I have kept the faith:", which might be something a very religious combat pilot might reference on the side of his combat airplane. That same-numbered chapter and verse in the FIRST book does not read anything like having to do with fighting or combat.
Cassidy was mainly inspired by Raoul Lufbery, the leading flying ace of the Escadrille Squadron.
The character of Skinner is based on the Escadrille-pilot Eugene Bullard, an American who has gone to France and worked as a boxer there. He was also a son of a slave, just like Skinner.
James Franco earned his pilot's license in preparation for this film.