Experimental aircraft are specially designed planes used to test new technologies, designs, or concepts in aviation. These aircraft often serve as prototypes for future commercial or military planes, allowing engineers to gather data on performance, safety, and efficiency. Typically, experimental aircraft are built under specific regulations set by aviation authorities, such as the Federal Aviation Administration (FAA) in the United States. They may feature innovative materials, advanced avionics, or unique aerodynamic shapes, helping to push the boundaries of what is possible in flight.