Build your own Wright Brothers flyer
The Wright Brothers building a self-propelled airplane certainly ranks in humanity's top twentieth century achievements. 110 years later now you too can achieve basic flight, thanks to these beautifully-detailed blueprints that tell you all sorts of information you never new about the plane, including how to put one together.
The terms on here all meant something back in the day, so it's totally not weird to ask someone to "insert a wood stiffener behind your sprocket and chain." All you've gotta do is chop down a spruce strap on a decent lawnmower engine, toss in some stretched canvas and remind yourself repeatedly that neither Wright brother died in a plane crash, and you're all set.