Mitsubishi A5M - A6M2 Model 11 / 21
19 May 1937: The IJNAF issues preliminary planning documents for the Prototype 12-Shi carrier-
based fighter, intended as a replacement for the Mitsubishi A5M Type 96 "Claude".
7 July 1937: Beginning of the 2nd Sino-Japanese War that ended 9 September 1945. The 1st
Sino-Japanese War was from 1 August 1894 to 17 April 1895.
September 1937: The A5M Type 96 makes its combat debut over China.
5 October 1937: The IJNAF issues its final planning requirements for the Prototype 12-Shi
Carrier Fighter; A maximum speed of 270 knots (311 mph.) at 4,000 m., A climb to 3,000 m.
in 3.5 minutes. A range of 1,010 mls. on internal fuel and 1,685 mls. with auxiliary drop
tank. Maneuverability equal or better than the A5M. A wingspan of no more than 12 meters.
Armament to be 2 x 20 mm. cannon in the wings and 2 x 7.7 mm. machine guns in the
upper cowl + carry 2 x 60 kg. bombs. It had to be able to take off in less than 230 ft. into
a 30 mph. wind. The landing speed of less than 58 knots (67 mph.).
17 January 1938: Nakajima leaves the competition ofter a technical review held at the
Naval Aircraft Establishement at Yokosuka. They felt the requirements were too
April 1938: Mitsubishi's design was approved by the Technical Staff.
19 March 1939: 1st A6M1 prototype was completed at Mitsubishis Nagoya plant and
transferred by ox-drawn cart to the Army's training airfield at Kagamigahara. It was
designed by a team lead by Jiro Horikoshi.
Engine: Mitsubishi Zuisei 13: 875 hp.
1 April 1939: 1st flight of the A6M1 with Mitsubishi's test pilot Katsuzo Shima. A slight
vibration in flight was noticed.
17 April 1939: The two-blade variable pitch propeller of the original A6M1 was
replaced with a three-blade constant speed unit which ended the vibration
25 April 1939: The A6M1 prototype attained 265 knots/3,000 m. (305 mph./9,842 ft.).
1 May 1939: The Koku Hombu advised Hirokoshi that the IJNAF intended to replace
the Mitsubishi Zuisei 13 engine with the Nakajima Sakae 12 offering 950 hp. The
IJNAF designates the two Zuisei-powered prototypes the A6M1 and the Sakae-
powered model the A6M2.
18 October 1939: 1st flight of the 2nd A6M1 prototype.
December 1939: The A6M2 prototype began flight trials. Performance and
maneuverability exceeded all requirements.
21 July 1940: Yokosuka Kokuta sent 15 Type 0 fighters to China for operational
testing by the 12th Kokutai based at Hankow. Armament: 2 x 20 mm./60 rpg
wing cannon + 2 x 7.7 mm./500 rpg. cowl machine guns.
31 July 1940: The IJNAF formally accepted the Type 0 fighter as the Mitsubishi
A6M2 Type 0 Carrier Fighter Model 11. This was shortened to Zero-Sen.
19 August 1940: 1st mission of the 12th Kokutai.
13 September 1940: Zero-Sen pilots claim 27 Chinese fighters shot down over
Chungking in their first combat with Chinese I-15bis and I-16 fighters with
Note: By the end of 1940 the 12th Kokutai pilots had claimed 59 fighers destroyed
in aerial combat plus another 101 destroyed on the ground for the loss of 3
Zero-Sens to anti-aircraft fire. This is where the legend of the Zero-Sen's
Note: To allow the Zero-Sen to fit on the carrier elevators better, Mitsubishi
introduced folding wingtips on the 65th production aircraft. This became the
A6M2 Model 21.
Mitsubishi A6M4 Model 41 / 42
1943: Two A6M2s were fitted with experimental turbo-superchargers for high
altitude interception. The lack of proper material caused fires and poor
Edited by CORSNING, 22 January 2017 - 07:18 PM.