Mitsubishi A5M

The Mitsubishi A5M, Japanese Navy designation was "Type 96 carrier-based fighter" (九六式艦上戦闘機) was a Japanese carrier-based fighter aircraft. It was the world's first monoplane shipboard fighter and the direct ancestor of the famous Mitsubishi A6M 'Zero'. The Allied reporting name was Claude.

Design and development
In 1934, the Imperial Japanese Navy prepared a specification for an advanced fighter, requiring a maximum speed of 350 km/h (220 mph) at 3,000 m (9,840 ft) and able to climb to 5,000 m (16,400 ft) in 6.5 minutes. This 9-shi (1934) specification produced designs from both Mitsubishi and Nakajima.

Mitsubishi assigned the task of designing the new fighter to a team led by Jiro Horikoshi (later responsible for the famous A6M Zero). The resulting design, designated Ka-14 by Mitsubishi, was an all-metal low-wing fighter, with a thin elliptical inverted gull wing and a fixed undercarriage, which was chosen as the increase in performance (estimated as 10% in drag, but only a mere 3% increase in maximum speed) arising from use of a retractable undercarriage was not felt to justify the extra weight. The first prototype, powered by a 447 kW (600 hp) Nakajima Kotobuki 5 radial engine, flew on 4 February 1935. The aircraft far exceeded the requirements of the specification, with a maximum speed of 450 km/h (279 mph) being reached. The second prototype was fitted with a revised, ungulled wing, and after various changes to maximize maneuverability and reduce drag, was ordered into production as the A5M.

With the Ka-14 demonstrating excellent performance, the Imperial Japanese Army Air Force ordered a single modified prototype for evaluation as the Ki-18. While this demonstrated similar performance to the Navy aircraft and hence was far faster than the IJAAF's current fighter, the Kawasaki Ki-10 biplane, the type was rejected by the army owing to its reduced maneuverability. The Army then produced a specification for an improved advanced fighter to replace the Ki-10. Mitsubishi, busy turning the Ka-14 into the A5M, submitted a minimally changed aircraft as the Ki-33, this being defeated by Nakajima's competing aircraft, which was ordered into service as the Ki-27.

Operational history
The aircraft entered service in early 1937, soon seeing action in pitched aerial battles at the start of the Second Sino-Japanese War, including air-to-air battles with the China Air Force's Boeing P-26C Model 281 "Peashooters" in what was the world's first-ever aerial dogfighting and kills between monoplane fighters built of mostly metal. Chinese Nationalist pilots, particularly those flying the Curtiss Hawk III, put up a valiant fight against the Japanese. Even so, the A5M was the better of every fighter aircraft it encountered. Though armed with only a pair of 7.7 mm machine-guns, the new fighter proved effective and damage tolerant, with excellent maneuverability and robust construction. A5M's escorting the then-modern but vulnerable Mitsubishi G3M bombers in raids effectively turned back defense by the Chinese Nationalist air force.

The Mitsubishi team continued to improve the A5M, working through versions until the final A5M4, which carried an external underside drop tank to provide fuel for extended range.

The A5M's most competitive adversary in the air was the Polikarpov I-16, a fast and heavily armed fighter flown by both Chinese Air Force regulars and Soviet volunteers. Fierce air battles in 1938, especially on 18 February and 29 April, ranked among the largest air battles ever fought at the time. The battle of 29 April saw 67 Polikarpov fighters against 18 G3Ms escorted by 27 A5Ms. Each side claimed victory: the Chinese/Soviet side claimed 21 Japanese aircraft (11 fighters and 10 bombers) shot down with 50 of its own airmen killed; the Japanese claimed only two G3Ms and two A5Ms shot down with no less than 40 Chinese planes shot down.

104 A5M aircraft were modified to accommodate a two-seater cockpit. This version, used for pilot training, was dubbed the A5M4-K. K version planes continued to be used for pilot training long after standard A5Ms left front-line service.

Almost all A5Ms had open cockpits. A closed cockpit was tried but found little favor among Navy aviators. All had fixed, non-retractable undercarriage. Wheel spats were a feature of standard fighters but not training planes.

The Flying Tigers encountered the Type 96, although not officially, and one was shot down at Mingaladon airfield, Burma on 29 January 1942.

Some A5Ms remained in service at the end of 1941 when the United States entered World War II in the Pacific. US intelligence sources believed the A5M still served as Japan's primary Navy fighter, when in fact the A6M 'Zero' had replaced it on first-line aircraft carriers and with the Tainan Air Group in Taiwan. Other Japanese carriers and air groups continued to use the A5M until production of the Zero caught up with demand. The last combat actions with the A5M as a fighter took place at the Battle of the Coral Sea on 7 May 1942, when two A5Ms and four A6Ms of the Japanese carrier JAPANESE AIRCRAFT CARRIER Shōhō fought against US planes that sank their carrier.

In the closing months of the war most remaining A5M airframes were used for kamikaze attacks.

Versions
Data from
 * Ka-14
 * Six prototypes with various engines and design modifications.


 * A5M1
 * Navy carrier-based fighter, Model 1 : first production model with 633 kW (850 hp) Kotobuki 2 KAI I engine.


 * A5M2/2a
 * Model 21: More powerful engine.


 * A5M2b
 * Model 22: First production examples with NACA cowling and 477 kW (640 hp) Kotobuki 3 engine.


 * A5M3a
 * Prototypes with 448 kW (601 hp) Hispano-Suiza 12 Xcrs engine.


 * A5M4
 * Model 24 (ex-Model 4): The A5M2b with different engine, closed cockpit, additional detachable fuel tank. The last production models (Model 34) with Kotobuki 41 KAI engine.


 * A5M1-A5M4:
 * 780 constructed by Mitsubishi. 39 constructed by Watanabe, 161 manufactured by Naval Ohmura Arsenal.


 * A5M4-K
 * Two seat trainer version of A5M4, 103 constructed by Naval Ohmura Arsenal.


 * Ki-18
 * Single prototype land-based version for IJAAF, based on the A5M. 410 kW (550 hp) Kotobuki 5 engine.
 * Single prototype land-based version for IJAAF, based on the A5M. 410 kW (550 hp) Kotobuki 5 engine.


 * Ki-33
 * Two prototypes, a development of Ki-18 with a different engine, and closed cockpit.
 * Two prototypes, a development of Ki-18 with a different engine, and closed cockpit.


 * Total Production (all versions): 1,094

Operators
Data from
 * 🇯🇵 Japan


 * [[Image:War flag of the Imperial Japanese Army.svg|22x20px|border]] Imperial Japanese Navy Air Service
 * Aircraft carrier Akagi
 * Aircraft carrier Hōshō
 * Aircraft carrier Kaga
 * Aircraft carrier Ryūjō
 * Aircraft carrier Shōhō
 * Aircraft carrier Sōryū
 * Aircraft carrier Zuihō
 * Chitose Kokutai
 * Oita Kokutai
 * Ōminato Kokutai
 * Omura Kokutai
 * Sasebo Kokutai
 * Tainan Kokutai
 * Yokosuka Kokutai
 * 12 Air Corps
 * 13 Air Corps
 * 14 Air Corps
 * 15 Air Corps