In show they created Mecha before a Plane. Even though they have created plane but still use airship. They have tanks 50 years before any cars. They created a complex drill machine before other thing.
In show they created Mecha before a Plane. Even though they have created plane but still use airship. They have tanks 50 years before any cars. They created a complex drill machine before other thing.
Big note on that last point: the Fire Nation knew that air combat was a possibility because, up until 100 years prior to the events of ATLA, the Air Nomads existed and were able to fly. We didn’t have that.
Air nomads could fly, but they didn’t attack other nations. They knew just as well that flight was possible because birds can fly. They just couldn’t access that ability.
Air nomads didn’t attack other nations, but they were attacked at least once. And it would have made sense to develop techniques that allowed them to maximize maneuverability in combat. Either way, it doesn’t matter if they actually fought in the air. A military minded person would realize that being able to attack from the sky would be valuable, so just seeing a person flying would be enough to form a concept.
As for your bird remark… Bro, you ever seen a bird? Show me a bird the size and weight of a human. Of course they knew things could fly, just as we did. The difference is that they knew that humans could fly while we did not.
To a fire bender, an air bender might as well be a whole other species. That was my point with the bird.