Category Archives: Reconnaissance

Reconnaissance

Kawanishi H8K2 “Type 2 Flying Boat, Model 12“, (Nishiki Hikōtei 12-gata), (“Emiliy”), 901st. Naval Air Corps_Combined Maritime Escort Force, (Hasegawa)

TYPE: Long-range Maritime Reconnaissance and Bomber Flying Boat

ACCOMMODATION: Crew of ten

POWER PLANT: Four Mitsubishi MK4Q “Kasei 22” radial engines, rated at 1,380 hp each

PERFORMANCE: 290 mph at 16,400 ft

COMMENT: The Kawanishi H8K “ Type 2 Large-sized Flying Boat) was an Imperial Japanese Navy flying boat used during WW II for maritime patrol duties. The Allied reporting name for the type was “Emily”.
At the same time the type’s predecessor, the Kawanishi H6K, was going into service in 1938 the Navy ordered the development of a larger, longer-ranged patrol aircraft under the designation “Navy Experimental 13-Shi Large-size Flying Boat”. The result was a large, shoulder-winged design that is widely regarded as the best flying boat of the war. Despite this, initial development was troublesome, with the prototype displaying terrible handling on the water. Deepening of the hull, redesigning of the planing bottom and the addition of spray strips under the nose rectified this. Two further prototypes— actually pre-production aircraft— joined the development program in December 1941. The IJNAF accepted the first production version as the H8K1, “Navy Type 2 Flying Boat, Model 11”, of which 14 would be built.
The H8K1 entered production in 1941 and first saw operational use on the night of 4 March 1942 in a second raid on Pearl Harbor. Since the target lay out of range for the flying boats, this audacious plan involved a refueling by submarine, some 900 km north-west of Hawaii. Two planes from the Yokohama Kokutai (Naval Air Corps) attempted to bomb Pearl Harbor, but, due to poor visibility, did not accomplish any significant damage.
Six days after the second Pearl Harbor raid one of the “Emily’s” was sent on a daylight photo-reconnaissance mission of Midway Atoll. It was intercepted by radar directed Brewster F2A-3 “Buffalo” fighters of Marine Corps squadron VMF-221 and shot down.
After serving as an engine test bed for the Kasei 22 powered H8K2, the original H8K1 experimental aircraft was again modified as the prototype for a transport version of the H8K series. The deep hull made possible the installation of two decks, the lower deck extending from the nose to the rear hull step and the upper extending from the wing centre-section to the rear of the hull. Accommodation was provided for either twenty-nine passengers or sixty-four troops, the armament was reduced to one flexible 13mm Type 2 machine gun in the nose turret and one 20 mm Type 99 Model 1 cannon in the tail turret. A total of thirty-six H8K-2L transport flying boat “Seiku” (“Clear sky) were built between 1943 and 1945 and exclusively operated by Naval transport units.
An improved version of Kawanishi H8K2 “Type 2 Flying Boat, Model 12” (Nishiki Hikōtei 12-gata) soon appeared, and it’s extremely heavy defensive armament earned it deep respect among Allied aircrews. The H8K2 was an upgrade over the H8K-1, having more powerful engines, slightly revised armament, and an increase in fuel capacity. They were used on a wide range of patrol, reconnaissance, bombing, and transport missions throughout the Pacific war. In mid 1943, many aircraft were equipped with Mark IV Model 1 ASV radar. This was to be the definitive variant, with 112 aircraft produced.
Even though far fewer Kawanishi H8Ks were built than contemporary British Short “Sunderlands” or American Consolidated PBY “Catalinas”, the Japanese flying-boat emerged from conflict as the most outstanding water-based combat aircraft of the second World War (Ref.: 1, 24).

Nakajima J1N1 C-Kai ‘Gekko’_251st Kokutai (Fujimi)

TYPE: Reconnaissance aircraft, night fighter

ACCOMMODATION: Crew of two

POWER PLANT: Two Nakajima NK1F “Sakae 21” air-cooled radial engine, rated at 1,130 hp each

PERFORMANCE: 315 mph at 19,160 ft

COMMENT: The Nakajima J1N1 “Gekko” (“Moonlight”) was a twin-engine aircraft used by the Japanese Imperial Navy during WW II and was used  for reconnaissance, night fighter and “Kamikaze” missions. The first flight took place in May 1941. It was given the Allied reporting name “Irving”, since the earlier reconnaissance version the Nakajima J1N1, was mistaken for a fighter.
In mid-1938 the Japanese Imperial Navy requested a twin-engine fighter designed to escort the principal bomber used at the time, Mitsubishi G3M “Nell”. The operating range of the standard Navy fighter, the Mitsubishi A5M “Claude”, was only 750 m), insufficient compared with the 2,730 mi of the G3M. Moreover, at the time, the potential of the Mitsubishi A6M “Zero”, then still under development, remained to be evaluated, stressing the need for a long-range escort fighter, much as the German Luftwaffe had done with the Messerschmitt Bf (Me) 110 “Zerstörer” (“Destroyer”), introduced the year before.
In March 1939, Mitsubishi and Nakajima began the development of a project 13-Shi. The prototype left the factory in March 1941 equipped with two 1,130 hp Nakajima Sakae 21/22, radial engines. There was a crew of three, and the aircraft was armed with a 20 mm Type 99 cannon and six 7.7 mm Type 97 machine guns. Four of these machine guns were mounted in two rear-mounted powered turrets, the weight of which reduced the performance of the aircraft considerably. Because of the sluggish handling, being used as an escort fighter had to be abandoned. Instead, production was authorized for a lighter reconnaissance variant, the J1N1-C, also known by the Navy designation Navy Type 2 Reconnaissance Plane. One early variant, the J1N1-F, had a spherical turret with one 20 mm Type 99 Model 2 cannon mounted immediately behind the pilot.
In early 1943, Commander Y. Kozono of the 251st Kokutai in Rabaul came up with the idea of installing 20 mm cannons, firing upwards at a 30 degree angle in the fuselage. Against orders of central command, which was skeptical of his idea, he tested his idea on a J1N1-C as a night fighter. The field-modified J1N1-C KAI shot down two Boeing B-17s “Flying Fortress” of 43rd Bomb Group attacking air bases around Rabaul on 21 May 1943.
The Navy took immediate notice and placed orders with Nakajima for the newly designated J1N1-S night fighter design. This model was christened the Model 11 “Gekko” (“Moonlight”). It had a crew of two, eliminating the navigator position. Like the J1N1 KAI, it had twin 20 mm Type 99 Model 1 cannon firing upward in a 30° upward angle, but added a second pair firing downward at a forward 30° angle, allowing attacks from above or below. This arrangement was effective against B-17 “Flying Fortress” bombers and Consolidated B-24 “Liberators”, which usually had Sperry ball turrets for ventral defense. The “Gekko’s” existence was not quickly understood by the Allies, who assumed the Japanese did not have the technology for night fighter designs. Early versions had nose searchlights in place of radar. Later models, the J1N1-Sa Model 11a, omitted the two downward-firing guns and added another 20 mm cannon to face upward as with the other two. Other variants without nose antennae or searchlight added a 20 mm cannon to the nose. Many “Gekkos” were also shot down or destroyed on the ground. A number of “Gekkos” were relegated to Kamikaze attacks, using 250 kg bombs attached to the wings. A total of 479 Nakajima J1N1 “Gekkos” were built before the war in the Pacific area was ended (Ref.: 24).

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).