It could be that there is a librarian who discovers the flying books and tries to understand what's going on. So the librarian and the flying books are the main characters. The librarian might be curious and a bit scared at first but then grows to love the flying books and their adventures.
Perhaps the main characters are the flying books themselves. Each book could have its own character traits based on its content.
There might be a young child who is the only one who can see the flying books at first. The child then becomes friends with the books and helps them on their journey. So the child and the flying books are the main characters. The child could be lonely before meeting the books and through their adventures together, they both learn and grow.
Since it's about flying poodles, the main characters are probably the poodles themselves.
I don't know for sure since I haven't read the story, but it could be some adventurous kids who find the flying canoe and are the main characters.
There's also the emperor. He is a very important character as he represents the power and the establishment. His reaction to the flying machine is crucial in driving the story forward. When he sees the flying machine, he has to decide what to do about this new and potentially dangerous thing in his kingdom.
The main character is the captain of the Flying Dutchman. He is the one who is cursed along with his ship.
I'm not sure as the story isn't described here. But usually in a flying lessons story, there could be a student who is eager to learn to fly and a teacher or instructor who imparts the knowledge.
I don't know for sure as I haven't read it. But surely the flying man is one of the main characters. There may also be other characters like his friends or foes who interact with him in the story.
Perhaps the main characters are the entrepreneurs who are investing in flying car projects. They play a crucial role in pushing the idea forward. Also, there might be some test pilots who are involved in the early flights of the prototypes.
Since I don't know the story, I can't say for sure. But it could be a young protagonist trying to find their place in the world, or maybe a group of friends on an adventure together.
The main characters are three Vietnam War veterans.
I'm not sure specifically as I haven't read every 'fear of flying novel'. But usually, there would be a character who has the fear of flying as the central figure.