The Friedrichshafen FF.54 was a German experimental quadruplane that was developed by Flugzeugbau Friedrichshafen during the First World War.
It was equipped with a 160 hp Mercedes D.IIIa in-line engine. The armament consisted of two LMG 08/15 machine guns that fired through the propeller. The first flight took place on October 31, 1917. The aircraft crashed on the first flight.[1] It was later rebuilt as a triplane, with the second wing from the top removed. The improved version was flown in May 1918, and crashed again. As a result, the project was discontinued in September 1918.