I think it was filmed around September 1940 when the 1st squadron was formed. Yeah a couple of rich guys helped form it and the guys had to come to Britain via Canada due to the US Neutrality Laws making it illegal for someone to fight. I recall the initial guys from 1940 where headed towards France to join up with them, but that whole France surrendering thing kinda got in the way and so they ended up with the RAF.
A very good book (in which I have and read) on the Eagle Squadron is Alex Kershaw's, The Few: The American "Knights of the Air", Who Risked Everything to Save Britain in the Summer of 1940. It's been a while since I have read it and should do it again as The Battle of Britain is a favorite subject of mine. Kershaw's very good and have I read others of his, The Longest Winter (Battle of the Bulge) and The Bedford Boys (19 boys from Bedford Virginia and what happened to them).
That must have been filmed not long before Dunkirk... because the guy talked about them "going to the front" after they were trained... but IIRC they didn't actually see action as a unit until the Battle of Britain... (although some of the individuals had been in the RAF and/or in the French AF before France went down...)
Also, the guy said they paid their own way to get there, but I don't think most of those guys did... I think there was a couple rich guys who helped make it happen by actively recruiting them and getting them there... I used to know more details, including about how there were three such squandrons which eventually got transferred to the 8th Air Force, but that was ages ago...
I think those are Hurricanes in the film... but I think at least one of the Eagle Squadrons had Spitfires... I forget the details...
John Keegan, a renowned British military historian, has called World War II the greatest single event in the history of mankind. - Tom Brokaw, NBC special correspondent and author of "The Greatest Generation"