The Mitsubishi A5M “Claude” was the world’s first carrier-based monoplane fighter, serving as the direct predecessor to the legendary A6M Zero.
It entered service in 1937 and remained active in various roles until 1945.
The Mitsubishi A5M, formally designated the Navy Type 96 Carrier Fighter, was developed in response to a 1934 Imperial Japanese Navy specification calling for a fast, agile monoplane to replace ageing biplanes.
Designed by Jiro Horikoshi, the A5M prototype—known as the Ka-14—first flew in February 1935 and impressed with its speed and manoeuvrability.
It featured a low-wing monoplane layout, fixed landing gear, and an open cockpit, reflecting transitional design elements between biplanes and modern fighters.
Production began in 1936, and the A5M1 entered service in 1937.
It quickly became the mainstay of the Imperial Japanese Navy Air Service, equipping all IJN aircraft carriers until the arrival of the A6M Zero in 1940.
The A5M saw extensive combat in the Second Sino-Japanese War, where it proved superior to Chinese and Soviet-supplied aircraft.
Despite its limitations—such as lack of armour and self-sealing fuel tanks—it remained effective due to its agility and climb rate.
Variants included
Ka-14
The original prototype with a streamlined design and retractable gear (later abandoned).
A5M1
Initial production model with a 610 hp Kotobuki 2-KAI-1 engine.
A5M2a
Improved version with a more powerful Kotobuki 3 engine and minor aerodynamic refinements.
A5M2b
Featured an arrestor hook for carrier operations and optional drop tanks.
A5M3
Experimental version with a liquid-cooled Hispano-Suiza engine—ultimately unsuccessful.
A5M4
Final production variant with enclosed cockpit and drop tank capability; used for training and kamikaze missions late in the war.
Two Army prototypes—the Ki-18 and Ki-33—were derived from the A5M but rejected in favour of Nakajima’s Ki-27.
In total, 1,094 A5Ms were built, and while obsolete by 1941, the aircraft continued in secondary roles, including training and suicide missions in the final stages of WWII.
The A5M’s legacy lies in its pioneering role as the first shipborne monoplane fighter and its influence on the design of the A6M Zero, which would dominate the early Pacific War.
Its service marked Japan’s transition to modern air power and independence from Western aviation technology.
