Well, forever if you’re ok with your stove running forever. This is just a neat, and potentially dangerous, experiment where you can make a paper plane fly in a circle indefinitely. The design you see for the plane is pretty complex and not necessarily what you need, but the most important part is having the flaps at opposite angles like you can see towards the end of the crafting. A pretty cool experiment but maybe not the best idea to give a kid unless you can come up with a safe alternative to cranking up the stove.
