Wing Span: 36 feet, 11-3/32 inches
Length: 29 feet, 11 inches
Maximum Weight: 6,095 lb.
Performance:  Mitsubishi NK1F Sake Engine, 980HP at 19,685 feet
Top Speed: 351 mph
Range: 1,171 miles at cruising speed of 230 mph
Ceiling: 38,520 feet
Rate of Climb: 2,526 feet per minute
Armament: Two Type 99 20mm cannons; one each wing; and two Type 97 machine guns in upper fuselage; Two 132-lb bombs, one under each wing
 

The A6M2 and it follow-on versions were considered one of the finest carrier fighter designs of WWII.

Pre-War War II:

In 1937, in light of combat reports from China, the Imperial Japanese Navy established specifications for a new carrier fighter aircraft.  The aircraft had to achieve a maximum speed of 500 km/h at 4000 meters; a climb to 3000 meters in 3.5 minutes; an endurance a 1.5 to 2 hours at normal power and fully loaded and with additional fuel tank; or 6 to 8 hours at economical cruising speed; armament requirement consisted of two 20mm cannons and two 7.7 mm machine guns, and two 30 kg or 60 kg bombs; a complete radio set; a wing span of less than 12 meters; and maneuverability at least comparable to the A5M type 96 aircraft. 

The specifications were presented to the Nakajima and Mitsubishi aircraft manufacturing teams.  Nakajima considered the new requirements unrealistic and pulled out of the running.  The Mitsubishi team, led by Jiro Horikoshi, presented a two-bladed propeller, low-winged monoplane with a retractable landing gear, and powered by a Mitsubishi Zuisei 13 engine.  The aircraft presented a large canopy for an excellent view.  The first prototype, the A6M1, was flown my Katsuzo Shima on April 1, 1939.  The two-bladed propeller was soon replaced by  a three-bladed propeller.  On September 14, 1939, the Japanese Navy accepted the aircraft as the A6M1 Type 0 carrier fighter.  After further testing the Mitsubish Zuisei engine was repaced by the Nakajima Sakae engine and redesignated the A6M2.  On July 31, 1940, the A6M2, named "Reisen", entered into production as the Navy Type 0 carrier fighter, Model 11. 

First Combat:

In August 1940, 15 pre-production A6M2s went to China.  On September 13, 1940, 13 "Reisens", led by Saburo Shindo attacked 27 Chinese I-15s and I-16s--all the Chinese aircraft were shot down without any Japanese losses.

War War II:

In November 1940, the aircraft, was redesigned with manually folding wingtips so that the aircraft could fit on the deck elevators of Japanese aircraft carriers; it was designated as the Model 21.  Production continued for two years in the Mitsubishi and Nakajima plants.  A total of 1,540 aircrafts of this version were manufactured.  The model 21 took part in the attacks on Pearl Harbor, the Battle of Midway, the Philippines, the Dutch East Indies, the New Guinea and the Solomon operations. 

In October 1942, the Reisen (Zero) fought its last air campaign during the Battle of Santa Cruz.  Thereafter, the A6M2 was replaced by the A6M3 and relegated to second line duties and training.

The Reisen provided the basis for two other versions, the A6M2-N float plane, named the Rufe, and the A6M2-K two-seat trainer.

In the early years of the Pacific air war, the Reisen was a tight turning aircraft; it can turn on a dime. To gain its great maneuverability, it had to sacrifice amour protection for the pilot; thereby it was fragile and almost completely unprotected from enemy fire.  An American fighter armed with .50 caliber machine guns is likely to tear the A6M2 in half and instantly kill the pilot if given a chance to fire from the rear.  American pilots respected the Reisen by avoiding a dog fight.  The outcome is the A6M2 would most likely out maneuver the American fighter.  The American fighter pilot's best approach was a rapid dive onto the rear of the A6M2.