Category Archives: Reconnaissance

Reconnaissance

Kawanishi H6K4 “Type 97 Large Flying Boat” („Mavis“), 901st. Naval Air Corps, Combined Maritime Escort Force

TYPE: Long-range Maritime Reconnaissance and Bomber Flying Boat

ACCOMMODATION: Crew of nine

POWER PLANT: Four Mitsubishi “Kinsei 46” radial engines, rated at 930 hp each

PERFORMANCE: 211 mph at 19,685 ft

COMMENT: The Kawanishi H6K4 was an Imperial Japanese Navy flying boat used during WW II for maritime patrol duties. The IJ Navy designation was “Type 97 Large Flying Boat”, The Allied reporting name for the type was “Mavis”.
The aircraft was designed in response to a Navy requirement of 1934 for a long range flying boat and incorporated knowledge gleaned by a Kawanishi team that visited the Short Brothers factory in the UK, at that time one of the world’s leading producers of flying boats, and from building the Kawanishi H3K, a license-built, enlarged version of the Short “Rangoon”. The Type S, as Kawanishi called it, was a large, four-engine monoplane with twin tails, and a hull suspended beneath the parasol wing by a network of struts. Three prototypes were constructed, each one making gradual refinements to the machine’s handling both in the water and in the air, and finally fitting more powerful engines. The first of these flew on 14 July 1936 and was originally designated “Navy Type 97 Flying Boat”, later H6K. Eventually, 217 would be built.
H6Ks were deployed from 1938 onwards, first seeing service in the Sino-Japanese War and were in widespread use by the time the full-scale Pacific War erupted, in 1942. At that time of the war, four Kokutai (Air Groups) operated a total of 66 H6K4s.
The type had some success over South East Asia and the South Pacific. H6Ks had excellent endurance, being able to undertake 24-hour patrols, and were often used for long-range reconnaissance and bombing missions. From bases in the Dutch East Indies, they were able to undertake missions over a large portion of Australia. However, the H6K became vulnerable to a newer generation of heavier armed and faster fighters. It continued in service throughout the war, in areas where the risk of interception was low. In front-line service, it was replaced by the Kawanishi H8K “Type 2 Large-sized Flying Boat“, Allied code name “Emily” (Ref.: 24).

Mitsubishi F1M2 (“Pete”), IJN BS “Yamato” (Airmodel, Resin)

TYPE: Observation float seaplane

ACCOMMODATION: Pilot and observer

POWER PLANT: One Mitsubishi “Zuisei” air-cooled radial engine, rated at 875 hp

PERFORMANCE: 230 mph at 11,285 ft

COMMENT: The Mitsubishi F1M (Allied code name “Pete”) was a Japanese reconnaissance floatplane of WW II. The F1M was originally built as a catapult-launched reconnaissance float plane, specializing in gunnery spotting. The “Pete” took on a number of local roles including convoy escort, bomber, anti-submarine, maritime patrol, rescue, transport, and anti-shipping strike. The type was also used as an area-defense fighter and fought dogfights in the Aleutians, the Solomons and several other theaters. In the New Guinea front, it was often used in aerial combat with the Allied bombers and Allied fighters. It was the last biplane type of the Imperial Japanese Navy (IJN), with 1,118 built between 1936 and 1944. It provided the IJN with a very versatile operations platform and was allocated to nearly all Japanese battleships, cruisers, aircraft tenders, but also to several shore bases.

The aircraft shown here was operated from IJN battleship “Yamato” in August 1944. The “Yamato” was the lead ship of the “Yamato” class of Imperial Japanese Navy World War II battleships. She and her sister ship, “Musashi”, were the heaviest battleships ever constructed, displacing 72,800 tonnes at full load and armed with nine 46 cm 45 Caliber Type 94 main guns, which were the largest guns ever mounted on a warship. Neither ship survived World War II (Ref.: 24).

Kawanishi E15K1 “Shiun” (“Violet Cloud”, “Norm”)(Aoshima, Parts Scratch-built)

TYPE: High-speed reconnaissance float plane

ACCOMMODATION: Crew of two

POWER PLANT: One Mitsubishi MK4S Kasei 24 radial engine, rated at 1,850 hp

PERFORMANCE: 291 mph at 18,700 ft

COMMENT: In 1939 the Imperial Japanese Navy instructed the Kawanishi Aircraft Company to develop a two-seat high-speed reconnaissance floatplane, which was required to have sufficient performance to escape interception by land based fighters. It was planned to equip a new class of cruisers, intended to act as a flagship for groups of submarines operating six of the new floatplanes to find targets. Kawanishi designed a single-engine low-wing monoplane, powered by a 1,460 hp Mitsubishi MK4D Kasei 14 radial engine driving two contra-rotating two-blades propellers, the first installation of contra-rotating propellers produced in Japan, while a laminar flow airfoil section was chosen to reduce drag. It had a single main float under the fuselage and two stabilising floats under the wing. The stabilising floats were designed to retract into the wing, while the central float was designed to be jettisoned in case of emergency, giving a sufficient increase in speed to escape enemy fighters. It is noteworthy to mention that similar design was chosen by Kawabishi’s engineers for the new Kawanishi N1K1 “Kyofu” float seaplane fighter.
The first prototype of Kawanishi’s design, designated E15K1 in the Navy’s short designation system made its maiden flight on 5 December 1941. Five more prototypes followed during 1941-42. Problems were encountered with the retractable stabilising floats, resulting in several accidents when the floats could not be lowered for landing, and the system was eventually abandoned, with the stabilising floats being fixed, and a more powerful Mitsubishi MK4S Kasei 24 engine fitted to compensate for the increased drag.
Despite these problems, the E15K1 was ordered into limited production as the Navy Type 2 High-speed Reconnaissance Seaplane “Shiun” Model 11. Six were sent to Palau in the South Pacific, but these were quickly shot down by Allied fighters, as the jettisonable float failed to separate on demand (although subjected to wind tunnel testing, the float separation system had never been tested on the actual aircraft). This resulted in the cancellation of production in February 1944, with only 15 “Shiuns” completed, including the six prototypes (Ref.: 24).

Yokosuka R2Y1 “Keiun” (“Beautiful Cloud”), (Wings Models, Vacu-formed)

TYPE: Long-range reconnaissance aircraft

ACCOMMODATION: Pilot and radio operator/navigator

POWER PLANT: One Aichi Ha-70 (twin-coupled Aichi “Atsuta 30s”) twenty-four cylinder liquid-cooled engine, rated at 3,400 hp

PERFORMANCE: 447 mph at 32,810 ft

COMMENT: In 1942 the Japanese Navy initiated the development of a new class of aircraft to fulfil the role as long-range high-speed land-based reconnaissance aircraft. The first projected aircraft was planned around the new 2,500 hp twenty-four cylinder, liquid-cooled engine then under development by Mitsubishi. But in 1943, inspired by evaluation of the Heinkel He 119 V4 acquired from Germany that was powered by two coupled engines buried in the fuselage behind the cockpit the design was changed again. Now the Aichi Ha-70 twin-coupled “Atsuta “30 was installed in the fuselage driving a single six-bladed tractor propeller via an extension shaft. Completed in April 1945 the prototype made its first flight on 8 May 1945. Unfortunately, this flight had to be cut short because of an abnormal rise in oil temperature, while a few days later an engine fire on the ground necessitated a complete engine change. Before this could be done, the R2Y1 was destroyed by American bombs. At the end of the war a second R2Y1 prototype was under construction and the design of a turbojet engine-powered fast attack bomber R2Y2 had almost been completed (Ref. 1).