In "The Flying Machine," published by Ray Bradbury in 1953, the literal danger the Emperor perceives in the creation of the flying machine is that this innovation will cause people to move away from the beauty brought about by the creation, and cause some to find a way to use the invention for evil purposes, specifically flying over the Great Wall of China. In order to be assured that this does not happen, the Emperor kills the inventor, burns the invention, and "silences" all those who have witnessed the man flying in the sky.
However, figuratively, the danger the Emperor anticipates is change and advancement. The peace he enjoys comes from living an existence rooted in the present, in the moment. With inventions come change, and the Emperor fears change. It is not until the end that he realizes that his actions will not guarantee that progress will cease. Even though he loves and wants to hold onto his world as it is, he finally understands that if one man was inspired to fly by studying the birds, it is only a matter of time before another man will do the same.
The Emperor would rather hold onto his peaceful way of living rather than enjoy the beauty and benefits that come with advancement. However, progress cannot be stopped, though this is what the Emperor in the story has tried to do.