From the summer of 1940, the Zero served as the Japanese Navy's frontline fighter for 5 years. Flown by veteran pilots, the Zero dominated Allied fighters early in the war and gained a reputation of invincibility. Never truly replaced, the Zero soldiered on alone and remained a viable threat right up to the end of WWII.
The Zero’s Roots. Achieving the Impossible
In September 1937, with the 2nd Sino-Japanese War just underway, the Navy asked Mitsubishi and Nakajima to develop the successor of the A5M. The requirements of 500km/h top speed with high manoeuvrability, 6 hours flight endurance, and 20mm cannon armament were daunting and Nakajima withdrew. Mitsubishi continued on, again assigning Jiro Horikoshi, who created the A5M, as the chief designer. His design featured main wings spars made from Extra Super Duraluminium. A variable pitch propeller, retractable landing gear, a teardrop-shaped canopy, and an aerodynamic drop tank. The first prototype, powered by a 780hp Mitsubishi Zuisei engine, flew in April 1939. The more compact, lightweight, and fuel efficient 940hp Nakaijma Sakae 12 engine was later fitted, resulting in a top speed of over 500km/h, a then unheard of range for a fighter of over 3.000km, and excellent manoeuvrability. In july 1940, it was accepted into service as the Type 0 (A6M) fighter.
The Zero in Battle
Early Zeroes which were still in the testing phase were deployed to Hankou airbase in China to support long-range bombers, and they were followed by the A6M2a production variant in August 1940. Their first action against Chinese fighters came in mid-September, when 13 Zeroes took on 27 Russian-built I-15s and I-16s and destroyed them without loss. The arrival of the Zero effectively gave Japan air superiority over China.
In December 1941, the Japanese Navy staged a surprise attack on the US Pacific Fleet at Pearl Harbor. The 350 attacking aircrafts from 6 carriers, including A6M2b, sank 5 battleships and destroyed many aircrafts. This operation was made possible due to the Zero’s unrivalled range. Similarly, Zeroes escorted G3M and G4M bombers to decimate the US bases on Luzon in the Philippines from bases in southern Taiwan, over 800km away.
In June 1942, the Japanese Navy set out to destroy the US carrier fleet and capture Midway Island. However, US forces detected the plan, and in the ensuing battle Japan lost 4 carriers and nearly 300 aircrafts. A6M2b shot down over 100 US aircrafts during the battle, but many veteran airmen were lost together with their carriers.
August 1943 saw US forces capture the airfield of Guadalcanal to mark the start of a gruelling campaign. A6M2b from the Rabaul Air Group pushed the limits of their range as they flew 2.000km round trip missions. Although they continued to record successes after Japanese forces withdrew from Guadalcanal in December 1943, losses mounted as US fighters adopted hit-and-run tactics.
The Battle of the Philippine Sea took place in June 1944 when the Japanese Mobile Fleet moved to attack US forces which were landing on Saipan. Over 200 A6M2 and A6M5 took part, but they were flown by inexperienced pilots, and faced with radar-directed F6F fighters and AA guns firing proximity ant VT-fused shells, nearly all were shot down. With the loss of 3 aircraft carriers and nearly 400 aircrafts, Japan’s naval air groups could no longer carry our any more operations at sea.
Zero Variants
Following the Model 11 (A6M2a) which was deployed in China, the Model 21 (A6M2b) was the first true mass-production variant built for carrier use. 50cm folding wingtips were incorporated to facilitate handling on carrier elevators. They were also equipped with “Kruesi” radio direction finders and arrestor hooks, but many aircraft which operated from land bases had these removed.
Introduced in summer 1942, the Model 32 (A6M3) was powered by a Sakae 21 engine with 2 stage supercharger and an 11m wingspan with clipped wingtips. Although top speed increased by 11km/h and dive performance was improved, the added weight and smaller fuel capacity reduced its range by about 1.000km.
Deployed from early 1943, the Model 22 (A6M3) was rushed into development in order to correct the model 32’s shortcomings. Overall performance improved as the 12m wingspan and folding wingits were reintroduced to regain manoeuvrability and new wing fuel tanks restored range to 2.560km.
With a focus on maximizing speed, the Model 52 (A6M5) featured an 11m wingspan with rounded wingtips and an exhaust system which added an increment of thrust to enable a top speed of 565km/. About 6.000 A6M5 of all types were produced.
Credits: Tamiya, "Background Information" placed in the box of the model