Martin Kreutzer

Martin Kreutzer joined Fokker in 1913 as a welder and soon made a career, from chief welder, production manager to eventually designer/constructor.
He designed many M types, such as the M.5L (A-II), M.8 (A-1), M,19K (D-III) and all E (Enddecker) versions.
The M.21 was the last type designed personally by Martin Kreutzer, and was the result of an effort to create an improved version of the M.18 (D-I) fighter by strengthening the armament (two forward-looking machine guns) and installing a more powerful 160 HP Mercedes D III engine.
In addition, instead of the wing warping system used on the M.18ZF, the outer sections of the upper wing along the trailing edge were equipped with ailerons.

Martin Kreuzer died on 27 June 1916 after a crash with an M.18 (D-1), which he was flying.
He was succeeded by Reinhold Platz who completed the remaining work on the M-21.