Would you believe there was once an inflatable airplane? It's true. You can see it in the video above — wheel out the packed-away airplane, attach an air hose, inflate it, and take off. It was called the Goodyear Inflatoplane, and it actually flew.
The Inflatoplane was built by Goodyear as an experimental aircraft for the United States military. The company, famous for its blimps (oh, and also its tires) built 12 prototypes between 1956 and 1959, and testing of the inflatable plane continued until the early 1970s. It was then that the military finally lost interest, so no Inflatoplanes were ever actually manufactured for purchase. Still, it's a pretty cool piece of aviation history.