The Caspar U.1 (sometimes known as the Caspar-Heinkel U.1) was a 1920s German patrol seaplane designed by Ernst Heinkel and built by Caspar-Werke.

[1] To reduce the time to launch the aircraft, it was built as a cantilever biplane to remove the need to rig struts and wires on assembly.

[1] The U.1 had two single-step floats and was powered by a front-mounted 55-horsepower (41 kW) Siemens radial piston engine.

[1] The pilot had an open cockpit behind the upper wing which gave a clear view forward.

[1] Two aircraft were bought by the United States Navy for evaluation;[1] these were delivered to Naval Air Station Anacostia in late 1922, and were tested during 1923; one of the aircraft was damaged beyond repair whilst mounted on a truck for a parade.