As I said before, if it's about the Wright brothers' story, then Orville and Wilbur Wright are the main characters. They were the ones who worked hard to make the first powered flight possible.
The main characters are the bald man and the fly. Simple as that.
Since I don't know the exact 'the man can fly story', it could be an ordinary man who suddenly gains the power to fly. So, the main character would be this unnamed ordinary man.
I'm not entirely sure as the story isn't widely known to me in a very specific sense. But generally, there would likely be the people who can fly. Maybe there are leaders among them who guide the others in using their flying ability.
There could be a protagonist who is preoccupied with the fly. This character could be someone going through a period of boredom or self - reflection. The fly then becomes an object of their attention, and through their interaction with it, we learn about their character traits, like whether they are cruel, indifferent, or empathetic.
The main character is the scientist who conducts the ill - fated teleportation experiment. And, of course, the fly which accidentally gets involved in the experiment.
I'm not sure without reading the actual story, but it could be a young aviator who is eager to learn to fly.
I'm not sure specifically who the main characters are without more information about the 'Fly Boys True Story'. But they are likely young pilots who had some extraordinary experiences in the air.
Since I don't know the specific 'fly in the ointment short story', I can't say for sure. But it could be the person who discovers the 'fly in the ointment' and the one who is causing it. For example, in a story about a business deal, it might be the investor (the one who discovers the problem) and the unethical partner (the cause of the problem).
The main character is often a man who is faced with the presence of the fly. The fly can also be considered a character in a sense as it has an impact on the man's actions and thoughts.
The main characters are the spider and the fly. The spider is the predator, using cunning tactics to catch the fly.