The explanation lies with Hodgkinson, our third Ace of WWII, who lost his legs while practicing an aerial exercise blindfolded. Or more specifically, the answer lies with the follow-up question that story is likely to elicit: WHY WOULD THEY ENCOURAGE PEOPLE TO FLY A MILLION DOLLAR PIECE OF EQUIPMENT WHILE FREAKING BLINDFOLDED?
THIS IS A TERRIBLE IDEA
How It's An Advantage:
Unlike the Cracked Summer Intern Post-It Eating Contest, pilots didn't fly "blind" because their superiors needed something hilarious to gamble on. Being able to fly without actually seeing anything was a part of a fighter pilots job thanks to a little something called G-force. As pilots and roller coaster enthusiasts will tell you, G-force is fine in moderation. But ramp up the G's and that delightful tingle you get in your man pouch at the top of the first hill of a roller coaster can drain all the blood from your head, leaving you temporarily blind or, less temporarily, dead.
The fighter planes of the Second World War were capable of all kinds of airborne acrobatics that found pilots' bodies moving in the opposite direction of their blood. Dogfights were a constant balance between out-maneuvering the guy trying to turn you into confetti, and trying not to steer the sight out of your eyes. One hairpin turn and you'd find yourself with all the blood your brain needs for seeing down in your feet. Or at least, that was a problem for people who had legs for their blood to drain into.
Bader, sitting on his awesome secret weapons: Nothing.