When I was young my father told me stories about my grandfather, who was the leader of an anti-aircraft artillery team in the Imperial Japanese Army during WWII. My dad claims that there were competitions between the teams early in the war, and that these competitions would involve flying a banner behind a plane and attempting to hit a target painted on the banner. My grandfather was supposedly on the 3rd best team in Japan - according to my dad.
Is he full of shit? Or did this actually happen?
Older and slower planes, artillery spotting planes and trainer planes were often used as target tugs, towing a "saucage", often a cloth tube in a long line behind the target tug. Fighter pilots and AA gunner would fire on these targets to practice firing against moving and manouvering targets.
Competitions in sharpshooting, from the lowliest infantryman to the most esteemed fighter wing commander were very common in ww2 armies, so your story sounds plausible to me.