The first Ka-1 (the repaired Kellett KD-1A), first took off from Tamagawa Airfield on May 26, 1941. In the following Army trials, performance was deemed excellent. Originally, it was planned to send the Ka-1 to spot for the artillery units based in mainland China, but the change of the course of War in that theater rendered those plans meaningless. Instead, a few Ka-1 were sent to the Philippines to perform the duties of liaison aircraft as replacements for the
Kokusai Ki-76. After some time, the IJA finally decided on the best use of these unique aircraft, and the majority of Ka-1 and Ka-2 were pressed into service as anti-submarine patrol aircraft. Pilot training for this speciality started in July 1943, with the first batch of ten pilots graduating in February 1944; followed by another batch of forty pilots in September 1944. Originally, the plan was to deploy the Ka-1/Ka-2 from 2D-class cargo ships to spot enemy submarines, but these ships turned out to be too cramped for operations; therefore the Ka-1/Ka-2 unit was assigned to the Army-operated assault ship
Akitsu Maru from August 1944 until her sinking in November 1944. From 17 January 1945, ASW patrols were resumed from an airstrip on
Iki Island with a maintenance base located at Gannosu Airfield in
Fukuoka prefecture. ASW patrols also started from May 1945 from Izuhara airfield on
Tsushima Island. These missions helped to protect one of the last operational Japanese sea lanes between the ports of Fukuoka and Pusan. Eventually, U.S. carrier-based aircraft began to appear even in the Tsushima Strait, so, in June 1945, the Ka-1/Ka-2 units were relocated to
Nanao base on the
Noto Peninsula in the
Sea of Japan, operating from there until the end of the war. The Ka-1/Ka-2 did not directly sink any submarines during the war, but they were well-regarded for spotting enemy submarines and reporting their positions. ==Variants==