A $100 Hamburger is aviation slang for a private general aviation flight for the sole purpose of dining at a non-local airport. Most often used by pilots who are looking for any excuse to fly, a $100 hamburger trip usually involves flying a short distance (less than two hours), eating at an airport restaurant, and flying home. "$100" originally referred to the approximate cost of renting or operating a light general aviation aircraft, such as a Cessna 172, for the time it took to fly round-trip to a nearby airport, but renting or operating a small plane for 2-4 hours now costs considerably more than that.