World War I The third prototype was sent to the Naval Air Station Flanders I (, SFS I) at
Zeebrugge in
Occupied Belgium in May 1918 for a combat evaluation, although no records about its activities survive. The first documented combat involving the W.29 occurred on 4 June when four aircraft of the 1st
Squadron, SFS I, led by the commander,
Friedrich Christiansen, encountered a British flight of three
Felixstowe F2A flying boats searching for submarines, shooting down two and damaging the third. Two days later Christiansen led five W.29s from the 1st Squadron on a reconnaissance flight over the North Sea and spotted the British submarine surfacing. The floatplanes dropped to low altitude and machine-gunned the submarine, killing five men and puncturing its
ballast tanks so that it was forced to remain on the surface. On 18 July, 1 Squadron on a long-range reconnaissance patrol off the
Kentish coast with six or seven W.29s, surprised a pair of
Short 184 floatplanes on an anti-submarine patrol that were escorted by a pair of
Sopwith Camel land-based fighters. The guns of one British fighter soon jammed and they were unable to drive off the German aircraft. Both floatplanes were shot down, killing all four crewmen, while the Camels were able to disengage without damage. W.29s were also deployed at
Ostend, Belgium,
Norderney and
Borkum on the
German Bight. One group of six W.29s from Borkum discovered a group of six British
coastal motor boats on 11 August, searching for German
minesweepers. Attacks by the aircraft with machine guns and small bombs forced the boats to run for safety in neutral Dutch waters. Two boats were blown up by their crews after they had exhausted all their fuel and ammunition but the remaining boats were successful, albeit badly damaged. The Austro-Hungarian Navy () ordered 25 W.29s on 26 August 1918 to be built by
UFAG at its factory in
Budapest,
Hungary, with delivery to commence before 31 October. Only one was completed before the end of the war and it saw no combat. Ten others were still under construction at the end of the war. The German
airline Deutsche Luft-Reederei operated at least one W.29 as a
mail plane. The
Hungarian Soviet Republic, the successor state to the
Kingdom of Hungary in the
Austro-Hungarian Empire, ordered production of the W.29 at UFAG to restart. At least two were completed, which, with the W.29 completed for Austria-Hungary, were operated by the 9th Floatplane Squadron operating from the
Danube River near Budapest and saw combat against
Czechoslovak and
Romanian forces in 1919. The IJN aircraft were produced as the Hansa Type Reconnaissance Seaplane by
Aichi and the
Nakajima Aircraft Company as a replacement for the
Yokosuka Ro-go Ko-gata floatplane, beginning in 1924, although the numbers built are in dispute. Japanese aviation historians Robert Mikesh and Shorzoe Abe claim a total of 310 aircraft built (150 by Aichi and 160 by Nakajima) but aviation historian Colin Owers believes that this is improbable since the Yokosuka plane remained in production until 1924 and he estimates that Nakajima only built 30. Although the dimensions of the Japanese Hansas were almost identical to those of the W.29, they were nearly 50 percent heavier than the Hansa-built aircraft and they were disliked by the Japanese pilots. They complained of poor downward visibility, poor directional control on the water, that it was difficult to land and was less maneuverable than the Yokosuka floatplane. Despite the problems the Hansas were used by the
seaplane carrier in exercises in 1924 and 1925 and aboard
battleships and
light cruisers. They remained in front-line service until May 1929 and into the early 1930s as training aircraft. Some survivors were sold on the civilian market and used as mail planes, for fish spotting duties and as transports, modified with a four-passenger cabin replacing the rear cockpit. The
Royal Danish Navy purchased at least three W.29s in 1919 and copied the design for production by the Royal Danish Shipyard (
Orlogsværftet) which built 15 between 1921 and 1927. The aircraft were assigned to the 1st Air Squadron upon its formation in 1926, the type remaining in service until 1930. ==Variants==