Few American fighter pilots on their own survived a turning, twisting, close-in dogfight against a capable Japanese pilot flying a Mitsubishi A6m Zero Fighter Aircraft during World War II. Innovative tactics devised by U.S. Navy Commander John S. “Jimmy” Thach in 1942 returned the advantage to American pilots, but the Zero remained a deadly adversary until the war ended. The Japanese official designation was Rei Shiki Sento Ki (Type 0 Fighter). Type 0 referred to the year of the emperor’s reign when production of Zero fighters began in 2600 on the imperial calendar (Julian calendar year 1940). Pilots called it the Zero even after the official codename became ‘Zeke’ in 1942. This article explores why the Mitsubishi A6m Zero Fighter Aircraft remained one of the world’s most maneuverable fighters to the end of the war, examining its key design philosophies. The capabilities of aircraft like the Zero often blurred the lines, leading to comparisons such as fighter vs attack aircraft.
Zero chief designer Jiro Horikoshi assembled a team in 1937 to design a new fighter for the Imperial Japanese Navy with two primary goals in mind: to make the aircraft as maneuverable as possible and to provide it with enough range to escort Japanese bombers all the way to distant targets in China and back. Navy leadership set these requirements based on missions against Chinese targets during the Second Sino-Japanese War that began in July of that year. When Horikoshi and his team began working on the aircraft in October, they already knew that making the fighter as lightweight as possible would benefit both maneuverability and range.
Designing for Lightweight Performance
Horikoshi’s team designed lightness into the Zero’s airframe by paying close attention to many small details. As explained in a 1945 article about the Zero published in Aviation, “Nothing has been spared to keep weight down, neither excessive man-hours to manufacture complex units nor increasing maintenance difficulties for ground crews.” An example is the bracket made of sheet aluminum pierced with large lightening holes and riveted together to support the aileron control tube. Crafts persons could have made this subassembly more easily using fewer and larger metal pieces, but at the cost of increased weight. Workers cut lightening holes in many parts, and in several areas they used plywood instead of aluminum or steel as backing to reinforce the metal canopy frame and to reinforce the false spar that supported the ailerons and flaps in the wings. The design choices made for the Zero contrast sharply with the developments seen in later eras, including 60s fighter aircraft where different material science and combat needs drove design.
For heavier solid parts of the airframe, the team used “extra super duralumin,” which was developed in 1935 by Sumitomo Metal. By alloying zinc with aluminum, metallurgists made a strong lightweight metal that resisted fatigue. Horikoshi used it to build solid pieces such as the two main wing spars that brace the wing much like the keel braces a ship. The Alcoa company began using a similar aluminum alloy in 1943 called “7075.”
Airplanes are built in subassemblies. Wings, fuselage, tail, engine, and landing gear follow separate paths around a factory before workers join them together during final assembly. The fittings that attach the wings and fuselage together are strong and heavy. To make these parts smaller and reduce their weight, Horikoshi’s team permanently joined the wings to the Zero fuselage and designed the aft fuselage including the tail to more easily mount to the forward fuselage at a point just behind the cockpit. Each wing half-mounted the guns, the landing gear, and the fuel tanks, making the wings significantly heavier than the tail. The fittings needed to join the tail could be smaller and lighter because they only had to support the weight of the tail. The gross weight of the A6M2 Zero (5,555 lb.) was 1,871 lbs less than its primary adversary in spring 1942, the Grumman F4F-4 Wildcat (7,426 lb.). Understanding the design philosophy behind the Zero provides context for comparing different types of combat aircraft, such as exploring the differences between attack aircraft vs fighter.
Engine Location and Maneuverability
Locating the engine close to the cockpit didn’t just save weight, it made the Zero more maneuverable as well. The centers of gravity and the aerodynamic center of lift lie at points very near the cockpit and serve as the fulcrum through which the empennage acts as a lever. Keeping the engine close to the fulcrum allowed the aft fuselage to be shorter and save a bit more weight. The elevator retained enough leverage to push the Zero into a tight turn or loop when the pilot hauled back the stick.
Mitsubishi A6M2 Zero fighter aircraft on a Japanese aircraft carrier deck preparing for the Pearl Harbor attack
Wing loading, the weight supported by each square foot of an aircraft’s wing in level flight, also impacts maneuverability. Less wing loading generally means quicker maneuvering because there is less inertia to overcome when the pilot moves the controls to pitch, roll, and yaw the aircraft. At 24.3 lb/ft², the A6M2 Zero had a lower wing loading than the Grumman F4F-4 Wildcat at 28.6 lb/ft². The Zero design team used an engine that made around 300 horsepower less than the Pratt & Whitney R-1840 Twin Wasp powering the F4F-4 Wildcat. Newer American fighters more than doubled the Zero’s horsepower with a commensurate increase in wing loading and performance. The American pilots refused to attack Zeros unless they held a clear advantage in height or speed. When they did attack, they made one pass and hopefully “boomed” a Zero and continued right on going past, avoiding a dogfight. Once they were out of range, they regained the altitude or speed advantage and attacked again if possible and necessary, again one pass, boom, zoom away at speed or to regain altitude above the target. These tactics highlight the critical interplay between aircraft design and combat strategy, a relationship that continues to evolve with modern fighter aircraft technology and tactic.
Detailed view of the cockpit of a restored Mitsubishi A6M5 Zero fighter aircraft
The design principles that made the Mitsubishi A6M Zero fighter aircraft so formidable in dogfights were primarily rooted in its emphasis on lightweight construction and efficient aerodynamics. These factors gave it unparalleled maneuverability for its time, forcing adversaries to develop entirely new strategies to counter it. While lacking the speed, armament, and protection of later Allied designs, the Zero’s initial dominance in turning engagements solidified its place as a legendary aircraft of World War II. The progression from aircraft like the Zero to contemporary aerial platforms showcases a continuous evolution in military aviation, influencing discussions about the capabilities and roles of future military fighter aircraft.
Recovered Mitsubishi A6M2 Zero fighter aircraft from Akutan Island in flight showing design details
References
- Peatie, Mark R. Sunburst: The Rise of Japanese Naval Air Power, 1909-1941.
