The Kyushu Q1W Tokai (Eastern Sea) 'Lorna' was the first dedicated anti-submarine warfare aircraft to be produced for the Japanese navy, but wasn't a great success and was only produced in small numbers.
One of the great weaknesses in the Japanese war effort was the lack of any significant anti-submarine forces, a crucial weakness for a maritime empire that relied on shipping to bring resources from the newly conquered empire back to Japan. American submarines soon began to take a terrible toll of Japanese merchant shipping, and during 1942 the Navy issued a 17-Shi specification for an anti-submarine warfare aircraft. This was to be a three-seat aircraft, with a long endurance to allow it to patrol over the vast expanses of the Pacific, to be able to fly at low speed, to carry out diving attacks on enemy submarines and to be ready for service as quickly as possible.
Kyushu responded with a mid-winged twin engined aircraft, with a heavily glazed nose and large glazed greenhouse canopy (somewhat similar to the Junkers Ju 88). The wings had a straight central section and tapering outer sections, with straight edges to ease production. It was powered by two 610hp Hitachi GK2C Amakaze 31 nine-cylinder air-cooled radial engines, and was designed to use a new radar set. When this failed to emerge the aircraft had to use the less effective and larger Type 3 radar set and magnetic anomaly detection gear. It was armed with one rear firing 7.7mm machine gun and could carry two 551lb depth charges. It could also carry one or two 20mm cannon in the nose.
The prototype was completed in September 1943, and was accepted for production as the Navy Patrol Plane Tokai (Eastern Sea) Model 11 early in 1944. Only 153 aircraft were produced between then and the end of the war, and the aircraft was not a great success in service. By the time it appeared the vital convoys from the Dutch East Indies and Malaya to the Japanese home islands were threatened by Allied air power as well as submarines, and the lightly armed and slow Q1W1 was very vulnerable to Allied fighters.
Q1W1 Tokai Model 11
This was the main production version, with all metal construction. It accounted for most of the 153 aircraft built between September 1943 and the end of the war.
Q1W2 Tokai Model 21
A small number of Q1W2s were built with the standard metal construction at the front and wing and a wooden rear fuselage.
Q1W1-K Tokai Ren (Eastern Sea Trainer)
The Q1W1-K was an all wooden four seat training aircraft designed as an electronic equipment trainer.
Engine: Two Hitachi GK2C Amakaze 31 nine-cylinder air-cooled radial engine
Power (each): 610hp at take-off, 480hp at 4,290ft
Wing span: 52ft 5 29/32in
Length: 39ft 7 25.32in
Height: 13ft 6 1/8in
Empty Weight: 6,839lb
Loaded Weight: 10,582lb
Max Speed: 200mph at 4,395ft
Cruising Speed: 150mph at 3,280ft
Service Ceiling: 14,730ft
Range: 834 miles
Armament: One 7.7mm machine gun
Bomb-load: Two 551lb depth charges