Man Flies By Own Lung Power 5

The main idea of the joke was completely confused, which makes the case even more funny than it was supposed to be. In the original, it was not the force of Kochers breath that caused the rotors to turn. Instead, the pilot breathed normally into the box, triggering a chemical reaction that extracted the carbon dioxide from his breath and used it to power a small motor. The fact that carbon dioxide is not very combustible and thus would make a terrible fuel was part of the joke.

So, sometimes, the misunderstanding on top of th practical joke creates mutiple-layers hoax.