A mere ten years after Orville and Wilbur Wright soared over sand dunes in Kitty Hawk, North Carolina, aircraft started shooting down other aircraft in battle. … The first attempts to mount machine guns onto airplanes fared badly; bullets whizzed straight through the spinning propeller, splintering wood when they hit the blades. The French tried a crude fix, mounting steel wedges to the inside of each blade to deflect the bullets, but it was the Germans who finally solved the problem, when they mechanically coupled propellers with the firing mechanism of the machine gun, synchronizing bullets so they shot in between the blades of the propeller.14 Within a matter of weeks the French had copied, and then improved upon, this design, and for the remainder of the war both sides flew planes with forward-facing machine guns.

Emlen, Douglas J, Animal Weapons_ The Evoluti…, loc. 540