Caspar U.1

Caspar U.1
U.1 under test by the US Navy
Role	Submarine-launched patrol seaplane Type of aircraft
National origin	Germany
Manufacturer	Caspar-Werke
Designer	Ernst Heinkel
First flight	1922
Primary user	Reichsmarine
Number built	3

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] The U.1 was designed to fit into a cylindrical container to allow it to be carried, then launched from a submarine.^[1]

The U.1 was designed to meet a requirement to fit inside a cylindrical container 7.40 metres (24.3 ft) long with a diameter of 1.70 m (5 ft 7 in); this allowed the aircraft to be carried by a submarine.^[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] It is claimed that during tests, four men could remove the U.1 from the container and erect it in 1 minute 3 seconds.^[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.^[2]

 Germany

• Reichsmarine

 United States

• United States Navy

Data from Flight, June 1923^[3]

General characteristics

• Crew: Two
• Length: 6.20 m (20 ft 4 in)
• Wingspan: 7.80 m (25 ft 7 in)
• Height: 2.34 m (7 ft 8 in)
• Wing area: 14 m² (150 sq ft)
• Empty weight: 360 kg (794 lb)
• Gross weight: 510 kg (1,124 lb)
• Powerplant: 1 × Siemens 5-cylinder radial engine, 37 kW (50 hp)
• Propellers: 2-bladed

Performance

• Maximum speed: 145 km/h (90 mph, 78 kn)
• Cruise speed: 121 km/h (75 mph, 65 kn)
• Time to altitude: 7 mins to 1,000 m (3,300 ft)
• Landing speed: 75 km/h (47 mph; 40 kn)

Aircraft of comparable role, configuration, and era

• Cox-Klemin XS
• Parnall Peto
• Martin MS
• Yokosuka E6Y

Related lists

• List of United States Navy aircraft designations (pre-1962)
• List of flying boats and floatplanes

Wikimedia Commons has media related to Caspar U.1.

• The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985). Orbis Publishing.
• Herris, Jack (2020). German Aircraft of Minor Manufacturers in WWI: A Centennial Perspective on Great War Airplanes. Gret War Aviation Centennial Series (49). Vol. 1: Alter to Korn. n.p.: Aeronaut Books. ISBN 978-1-935881-85-8.
• Passingham, Malcolm (February 2000). "Les hydravions embarqués sur sous-marins" [Submarine-carried Seaplanes]. Avions: Toute l'aéronautique et son histoire (in French) (83): 7–17. ISSN 1243-8650.