Well, as has kindly been pointed out to me, I missed Mers-el-Kebir day, and I missed Battle of Britain day - but I haven't forgotten Henri Giffard day! On this day in 1852, near Paris, Giffard (sporting a top hat for the momentous occasion) made the first ever airship flight, covering a distance of 17 miles in about 3 hours. The airship was steam-powered (a whole 3 horsepower). This was the first controlled, powered flight in history. The shadow of the Zeppelin begins here!

Image source: Smithsonian Institution (negative 73-05535).