Mitsubishi A6M (Zero, Zeke, Hamp)
Type 0 (Reisen) Fighter

Wartime History
Probably the most famous Japanese aircraft of WWII, this fighter was light weight, extremely maneuverable and exceptional range made it aircraft legendary among the pilots who flew it and the enemies it battled. Designed to replace the A5M4 Claude, Mitsubishi's cheif designer, Jiro Horikoshi began the new design in 1937. It entered combat first in China on September 13, 1940. 

A surprise to the outside world, which dismissed Japanese airplane designs as inferior, the Reisen (Zero) was well armed, lightweight fighter that could not be out-turned, and had an amazing range. To this day, it remains the symbol of Japanese air power during WWII. It served thruought the duration of WWII from start to finish, participating in nearly every key battle.

Allied Nicknames - Zero, Zeke & Hamp
Zeke was its official code name, but the more popular "Zero" always stuck, and is often applied to any Japanese single engine fighter.

A6M2 Zero
A6M2 Model 21 Zero. Built by both Mitsubishi and Nakajima. By the end of September 1942, Nakajima had already produced 303 A6M2s Model 21 Zeros.

Nakajima created "dummy" numbers in their codes. The first number and the second number from the right are "dummy" number that equal 10. Example: 6541 (6+4=10)

A6M3 'Hamp'
This was the nickname briefly used for the A6M3 Zero. When it was first observed, this was believed to be another airplane type, due to its square wingtips. When understood to be another model of Zero the name was dropped. All A6M3s, Models 32 and 22, were built by Mitsubishi begining in June 1942. The manufacture numbers were derived by adding a "3" in front of the m/n. So the 274th A6M3 would have the coded 3274. By the end of October they'd built 250. Production for the month of November, was 67. That means Mitsubishi were producing Model 32s at the rate of 2.2 per day. 274-250=24. 24/2.2 = 10.9 days.

Model 22 Zero had folding wingtips and adjustable trim tab on the aileron.

Rufe (A6M2-N Floatplane Variant)
Other variants, such as the A6M2-N Rufe floatplane version of the fighter existed, a modified A6M2 with a centerline float and smaller wing floats.

Field Modified Two Seater
A two-seater version did exist, with the second crew member serving as an observer / wireless operator.  This was a field modification of A6M2 at Rabaul at least two examples existed.

A6M5 Zero
The general opinion is that the numbering started at 3904. More powerful engine and armament package. The first A6M5 flew in August of 1943. In spite of an increase in all-up weight of 440 pounds, the A6M5 was faster than the A6M3 Model 32, and could reach a maximum level speed of 351 mph at 19,685 feet.

A6M7 Reppu (A6M5c Model 51 Hei)
Only 9 examples built.

Production
A total of 10,964 examples were built of all models.