After the transfer of the flying boat FB.3 to the German Navy in the summer of 1914.
Max Oertz slightly modified the design of the boat.
The wing design and the front cockpit were changed, which could now be installed with a 7.92 mm LMG.14 Parabellum machine gun.
The new flying boat has been designated W.4.
In November 1914 and January 1915, two copies of the flying boat were handed over to the fleet, receiving flight numbers “63” and “75”.
In the early days of the 1st World War, W.4 flew reconnaissance in the Dover area, thus becoming one of the first German aircraft to fly over enemy territory.
