O.Thetford, P.Gray German Aircraft of the First World War (Putnam)

Caspar D I
Designed by Ernst Heinkel, this twin-engined, single-seat lighter was built by Hanseatische Flugzeug-Werke in late 1918, but it was destroyed in 1919 when a motor broke loose during a ground test. Engines, two 100 h.p. Oberursel U I rotaries.

J.Herris German Aircraft of Minor Manufacturers in WW1. Vol I (A Centennial Perspective on Great War Airplanes 49)

Caspar

   The Hanseatische Flugzeugwerke (Hanseatic Aircraft Works of Karl Caspar Ltd) was located in Fuhlsbuttel, Flugplatz, Hamburg. The initial firm was founded in November 1911, the alteration to the title being made in January 1917. Caspar had dealings with the Austrian industrialist Castillio Castiglioni that led to his Company becoming part of the Brandenburg empire. In late 1916, Caspar was released from Naval service and he founded Hanseatische Flugzeugwerke Karl Caspar A.G.
   In the summer of 1916 their flying school burnt down when there was an explosion in the Zeppelin hangar. New facilities were built and the construction works and airship hangar were enlarged to take the new airships, the Navy signing a contract with the Company to use the facilities.
   The Company repaired machines and built new aircraft. It specialised in the repair of G-type aircraft. In summer 1917 it licence-produced the Albatros C.III, and then Friedrichshafen G.III bombers. During the war it produced 200 Albatros C.III biplanes, 93 Friedrichshafen G.III and G.IIIa bombers, as well as a large quantity of spare parts.
   In 1917 the firm repaired 15 machines per month, and in 1918 built 35 C-types per month, repaired five G-types per month, as well as spare part manufacturing. In 1918 the school graduated 155 pupils.
   The IAACC found 75 aircraft and 48 motors as well as a large quantity of spare parts when it inspected the factory. The Caspar D.I twin rotary engine fighter was designed by Karl Caspar, the only non-licensed machine produced by the company during the war, - the U 1 was completed postwar.

M.Dusing German Aviation Industry in WWI. Volume 1 (A Centennial Perspective on Great War Airplanes 84)

Hanseatische Flugzeugwerke AG (Karl Caspar), Hamburg-Fuhlsbuttel (Hansa)

Aircraft Development:

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  Between 1917 and 1918, a twin-engine (2 x 110 hp Oberursel UR.II or LeRhone) biplane was built. During a test run, an engine mount broke and fatally injured an assembler. As a result, further development activities were abandoned. Further attention was focused on the licensed production of Albatros C.III reconnaissance aircraft as well as Friedrichshafen Fdh G.III and G.IIIa.
  Under the (unconfirmed) designation HFC D.I, construction of a 2-engine single-seater fighter developed by Ernst Heinkel was begun before the end of the war. However, Ernst Heinkel was not contractually employed by Caspar for about a year until mid-1921, which again casts doubt on the origin statement. After an engine mount failed during testing and a mechanic was fatally injured, this project was abandoned.

Форум Breguet's Aircraft Challenge

This twin-100 h.p. Oberursel U I powered single-seat fighter was designed to carry a Becker cannon.