Akutan Zero

The Akutan Zero is inspected by US military personnel onAkutan Island on July 11, 1942.

The Akutan Zero, also known as Koga's Zero and the Aleutian Zero, was a type 0 model 21 Mitsubishi A6M Zero Japanese fighter plane which crash-landed on Akutan Island during World War II. It was captured intact by the Americans in July 1942 and became the first flyable Zero acquired by the United States during the war. Following its capture, it was repaired and flown by American test pilots. As a result of information gained during these tests, American strategists were able to devise tactics to defeat the Zero, which was the Imperial Japanese Navy's primary fighter plane throughout the war.

The Akutan Zero was "a prize almost beyond value to the United States", and "probably one of the greatest prizes of the Pacific war". Japanese historian Masatake Okumiya noted that the acquisition of the Akutan Zero "was no less serious" than the Japanese defeat at the Battle of Midway, and that it "did much to hasten [Japan's] final defeat".

The Akutan Zero was destroyed in a training accident in 1945. Pieces of it are preserved in several museums in the United States.

The Mitsubishi A6M Zero fighter

A Mitsubishi A6M2 "Zero" Model 21 takes off from the aircraft carrier Akagi, to attack Pearl Harbor.

The Second Sino-Japanese War began in 1937. Attacks by Chinese fighter planes on Japanese bombers caused the Japanese to develop the concept of fighter escorts. The limited range of the Mitsubishi A5M "Claude" fighter used to escort the bombers caused the Japanese Navy Air staff to commission the Mitsubishi A6M Zero as a long-range land/carrier fighter.

The Zero, which first flew in 1939, was exceedingly agile and lightweight, with maneuverability and range superior to any fighter in the world at that time. The Zero was superior to anything the Allies would produce for the first two years of the war. To achieve this, however, Japanese engineers traded off durability. The Zero had no armor and no self-sealing fuel tanks. According to American author Jim Rearden, "The Zero was probably the easiest fighter of any in World War II to bring down when hit ... The Japanese ... were not prepared to or weren't capable of building more advanced fighters in the numbers needed to cope with increasing numbers and quality of American fighters." As a result, the Zero was the primary Japanese Navy fighter throughout the war. During the war, the Japanese manufactured roughly 10,500 Zeros.

In 1940 Claire Lee Chennault, leader of the Flying Tigers, wrote a report on the Zero's performance. United States Department of War analysts rejected it as "arrant nonsense", and concluded that the performance attributed to the Zero was an aerodynamic impossibility. Early in the war, the Zero outclassed any Allied fighter it encountered. According to American flying ace William N. Leonard, "In these early encounters and on our own we were learning the folly of dogfighting with [the Zero]."

During the attack on Pearl Harbor, nine Zeros were shot down. From these wrecks, the Allies learned that the Zero lacked armor and self-sealing fuel tanks, but little else about its capabilities. The Zero's flight performance characteristics – crucial to devising tactics and machinery to combat it – remained a mystery.

Prior to recovery of the Akutan Zero, technical information from three other downed Zeros was available to the Allies. One Zero (serial number 5349) piloted by Hajime Toyoshima crashed on Melville Island in Australia following the bombing of Darwin. The Zero was heavily damaged, and Toyoshima became the first Australian prisoner of the Pacific war. Another Zero, piloted by Yoshimitsu Maeda, crashed near Cape Rodney, New Guinea. The team sent to recover the plane erred when they chopped off the wings, severing the wing spars and rendering the hulk unflyable. The third came from China, where Gerhard Neumann was able to reconstruct a working Zero. He used a partly intact Zero (serial number 3372) which landed in Chinese territory, repaired with salvaged pieces from other downed Zeros. However, the bad conditions and long delivery time to the United States prevented Neumann's Zero from reaching United States for testing until after the recovery of the Akutan Zero.

Koga's final mission

Tadayoshi Koga (September 10, 1922 – June 4, 1942) was the pilot of the Akutan Zero.

In June 1942, as part of the Japanese Midway operation, the Japanese attacked the Aleutian islands, off the south coast of Alaska. A Japanese task force led by Admiral Kakuji Kakuta bombed Dutch Harbor on Unalaska Island twice – once on June 3 and again the following day.

Tadayoshi Koga, a flight petty officer, was launched from Japanese aircraft carrier Ryūjō as part of the June 4 raid. Koga was part of a three-plane section – his wingmen were chief petty officer Makoto Endo and petty officer Tsuguo Shikada. Koga and wingmen attacked Dutch Harbor, shooting down an American PBY-5A Catalina flying boat piloted by Bud Mitchell and strafing its survivors in the water. In the process, Koga's plane (serial number 4593) was damaged.

Koga's fighter over Dutch Harbor, moments after being hit. In this picture, it is trailing oil.

Tsuguo Shikada, one of Koga's wingmen, published an account of his actions in 1984 in which he claimed that the damage to Koga's plane occurred while his section was making an attack against two American PBY Catalinas anchored in the bay. This account omits any mention of shooting down Mitchell's PBY. However, both American and Japanese records contradict his claims. There were no PBYs in the bay that day. However, his claims do match American records from the attack against Dutch Harbor the previous day (June 3). Rearden notes that "It seems likely that in the near half-century after the event Shikada's memory confused the raids of June 3 and June 4 ... It also seems likely that in his interview, Shikada employed selective memory in not mentioning shooting down Michell's PBY and then machine gunning the crew on the water."

It is unknown who fired the shot that brought down Koga's plane, although numerous individuals have claimed credit for it. Photographic evidence strongly suggests it was hit by ground fire. Physical inspection of the plane revealed it was hit with small arms fire – .50 caliber bullet holes and smaller, from both above and below.

The crash

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Akutan Island

The fatal shot severed the return oil line, and the plane immediately began trailing oil. Koga reduced speed to prevent the plane's engine from seizing for as long as possible.

"The three Zeros flew to Akutan Island, 25 miles east of Dutch Harbor, which had been designated for emergency landings. Lying near the island was a Japanese submarine assigned to pick up downed pilots. At Akutan the three Zeros circled a grassy flat half a mile inland from Broad Bight. Shikada thought the ground was firm beneath the grass, but in his second pass he noticed water glistening. He suddenly realized Koga should make a belly landing. But by then Koga had lowered his landing gear, and was almost down."

The plane's landing gear mired in the water and mud, causing the plane to flip upside-down and skid to a stop. Although the aircraft survived the landing nearly intact, Koga died on impact, probably from a broken neck or a blow to the head. Koga's wingmen, circling above, had orders to destroy any Zeros that crash landed in enemy territory, but as they did not know if Koga was still alive, they could not bring themselves to strafe his plane. Ultimately, they decided to leave without firing on it. The Japanese submarine, stationed off Akutan Island to pick up pilots, searched for Koga in vain before being driven off by the USS Williamson.

Recovery

Bill Thies (left) piloted the PBY Catalina that discovered the Akutan Zero.

The crash site – which was out-of-sight of standard flight lanes and not visible by ship – remained undetected and undisturbed for over a month. On July 10, an American PBY Catalina piloted by Lieutenant William "Bill" Thies spotted the wreckage. Thies's Catalina had been patrolling by dead reckoning and had gotten lost. On spotting the Shumagin Islands, he reoriented his plane and began to return to Dutch Harbor by the most direct course – over Akutan Island. One of the crewmen spotted Koga's wreck. Thies's plane circled the crash site, noted its position on the map, and returned to Dutch Harbor to report it. Thies convinced his commanding officer, Paul Foley, to let him return with a salvage team. The next day, the team flew out to inspect the wreck. Navy photographer's mate Arthur W. Bauman took pictures as they worked.

Koga's body after it was pulled from the wrecked plane

Thies's team extracted Koga's body from the plane, searched it for anything with intelligence value, and buried Koga in a shallow grave. Thies's team then returned to Dutch Harbor, where Thies reported the plane as salvageable. The next day (July 12) a salvage team under Lieutenant Robert Kirmse was dispatched to Akutan. This team gave Koga a Christian burial in a nearby knoll, and set about recovering the plane, but the lack of heavy equipment (which they had been unable to unload after the delivery ship lost two anchors) stymied their efforts. On July 15, a third recovery team was dispatched. This time, with proper heavy equipment, the team was able to free the Zero from the mud and haul it to a nearby barge, without further damaging it. The Zero was taken to Dutch Harbor, turned right-side up, and cleaned.

The Akutan Zero was loaded into the USS St. Mihiel, and transported to Seattle, arriving on August 1. From there, it was transported by barge to Naval Air Station North Island near San Diego where repairs were carefully carried out. These repairs "consisted mostly of straightening the vertical stabilizer, rudder, wing tips, flaps, and canopy. The sheared off landing struts needed more extensive work. The three-blade sumitomo propeller was dressed and re-used." The Zero's red Hinomaru roundel was repainted with American insignia. The whole time, the plane was kept under 24-hour military police guard in order to deter would-be souvenir hunters from damaging the plane. The Zero was fit to fly again on September 20.

Analysis of the Zero

Eddie Sanders flying the plane

On September 20, 1942, Lieutenant Commander Eddie R. Sanders took the Akutan Zero up for its first test flight. He would make 24 test flights between September 20 and October 15. According to Sanders:

These flights covered performance tests such as we do on planes undergoing Navy tests. The very first flight exposed weaknesses of the Zero which our pilots could exploit with proper tactics ... immediately apparent was the fact that the ailerons froze up at speeds above 200 knots so that rolling maneuvers at those speeds were slow and required much force on the control stick. It rolled to the left much easier than to the right. Also, its engine cut out under negative acceleration due to its float-type carburetor. We now had the answer for our pilots who were being outmaneuvered and unable to escape a pursuing Zero. Go into a vertical power dive, using negative acceleration if possible to open the range while the Zero's engine was stopped by the acceleration. At about 200 knots, roll hard right before the Zero pilot could get his sights lined up.

In later test flights, Anacostia Naval Air Station director of flight testing Frederick M. Trapnell flew the Zero in performance while Sanders simultaneously flew American planes performing identical maneuvers. Following these, test pilot Melville "Boogey" Hoffman conducted more dogfighting tests.

Following testing by the Navy, the Zero was transferred from Naval Air Station North Island to Anacostia Naval Air Station. In 1944, it was recalled to North Island for use as a training plane for pilots being sent to the Pacific. A model 52 Zero, captured during the liberation of Guam was later used as well.

Data and conclusions from these tests were published in Informational Intelligence Summary 59, and Technical Aviation Intelligence Brief #3, and Informational Intelligence Summary 85. These results tend to somewhat understate the Zero's capabilities.

Consequences

While several sources have stated that information from the captured Zero was used to design the Grumman F6F Hellcat, the US carrier-borne fighter plane that succeeded the F4F Wildcat, the Hellcat had been designed, ordered, and a test model first flown by the date of discovery of the Akutan Zero. The first production F6F was flown on 4 October 1942, two weeks after the captured Zero was first test-flown by the U.S. While those tests did not influence the Hellcat's design, they did give knowledge of the Zero's handling characteristics, including its limitations in rolling right and diving. That information, together with the improved capabilities of the Hellcat, were credited with helping American pilots "tip the balance in the Pacific". American aces Kenneth A. Walsh and R. Robert Porter, among others, credited tactics derived from this knowledge with saving their lives. James Sargent Russell, who commanded the PBY Catalina squadron that discovered the Zero and later rose to the rank of Vice Admiral, noted that Koga's Zero was "of tremendous historical significance." William N. Leonard concurred, describing it thus: "The captured Zero was a treasure. To my knowledge, no other captured machine has ever unlocked so many secrets at a time when the need was so great."

Some historians dispute the degree to which the Akutan Zero influenced the outcome of the air war in the Pacific. For example, the Thach Weave, a tactic created by John Thach and used with great success by American airmen against the Zero, was devised by Thach prior to the attack on Pearl Harbor, based on intelligence reports from the Zero's performance in China.

Tadayoshi Koga is probably buried in Chidorigafuchi National Cemetery

The capture and flight tests of Koga's Zero is usually described as a tremendous coup for the Allies in that it revealed the secrets of that mysterious aircraft and led directly to its downfall. According to this viewpoint, only then did Allied pilots learn how to deal with their nimble opponents. The Japanese could not agree more ... Yet those naval pilots who fought the Zero at Coral Sea, Midway, and Guadalcanal without the benefit of test reports would beg to differ with the contention that it took dissection of Koga's Zero to create tactics that beat the fabled airplane. To them the Zero did not long remain a mystery plane. Word quickly circulated among the combat pilots as to its particular attributes. Indeed on 6 October while testing the Zero, [Akutan Zero test pilot Frederick M.] Trapnell made a highly revealing statement: 'The general impression of the airplane is exactly as originally created by intelligence – including the performance.'

The Akutan Zero was destroyed during a training accident in February 1945. While the Zero was taxiing for a take-off, a SB2C Helldiver lost control and rammed into it. The Helldiver's propeller sliced the Zero to pieces. From the wreckage, William N. Leonard salvaged several gauges which he donated to the U.S. Navy Museum. The Alaska Heritage Museum and the Smithsonian Air and Space Museum also have small pieces of the Zero.

In an attempt to repatriate Koga's body, American author Jim Rearden led a search for Koga's body on Akutan in 1988. He located Koga's grave, but found it empty. Rearden and Japanese businessman Minoru Kawamoto conducted a records search. They found that in 1947 Koga's body was exhumed by an American Graves Registration Service team and re-buried on Adak Island, further down the Aleutian chain. That team, unaware of Koga's identity, marked his body as unidentified. The Adak cemetery was excavated in 1953, and 236 bodies were returned to Japan. The body buried next to Koga (Shigeyoshi Shindo) was one of 13 identified; the remaining 223 unidentified remains were re-interred in Chidorigafuchi National Cemetery in Japan. It is likely that Koga was one of the unidentified ones. Rearden later wrote the definitive account of the Akutan Zero.

References

• Bergerud, Eric M. Fire in the Sky: The Air War in the South Pacific. Westview Press, 2001, ISBN 0813338697.
• Handel, Michael I. War, Strategy, and Intelligence. Routledge, 1989. ISBN 0714633119
• Lundstrom, John B. The First Team and the Guadalcanal Campaign: Naval Fighter Combat from August to November 1942. Naval Institute Press, 2005. ISBN 1591144728.
• Okumiya, Masatake, Jiro Horikoshi, and Martin Caidin. Zero! New York: E.P. Dutton & Co., 1956.
• O'Leary, Michael. United States Naval Fighters of World War II in Action. Poole, Dorset, UK: Blandford Press, 1980. ISBN 0713709561.
• The Oxford Guide to World War II. Edited by I.C.B. Dear. Oxford University Press, 1995. ISBN 9780195340969.
• Rearden, Jim. Koga's Zero – The Fighter That Changed World War II. ISBN 0929521560, second edition. Pictorial Histories Publishing Company, Missoula Montana, 1995. Originally published as Cracking the Zero Mystery: How the U.S. Learned to Beat Japan's Vaunted WWII Fighter Plane. ISBN 978-0811722353.
• Rearden, Jim. Koga's Zero – An Enemy Plane That Saved American Lives. Invention and Technology Magazine. Volume 13, Issue 2, Fall 1997. Retrieved on 2008-12-09
• Degan, Patrick Flattop Fighting in World War II. McFarland, 2003. ISBN 9780786414512

External links

• Bill Thies's website
• Zeros over China, 1941–1942. Ben Schapiro. The Warbird's Forum, May 2008 – An article describing the capture and repair of Gerhard Neumann's Zero in China in 1941
• War Prize: The Capture Of The First Japanese Zero Fighter In 1941. j-aircraft.com, December 3, 1999 – A second article describing the capture and repair of Gerhard Neumann's Zero
• Article on Yoshimitsu Maeda's crashed Zero