THE KILLING OF YAMAMOTO NOT AN ACCIDENT BUT PROVIDENTIAL

Background[edit]

Admiral Isoroku Yamamoto, commander of the Imperial Japanese Navy, scheduled an inspection tour of the Solomon Islands and New Guinea. He planned to inspect Japanese air units participating in the I-Gooperation that had begun April 7, 1943, and to boost Japanese morale following the disastrous evacuation of Guadalcanal. On April 14, the U.S. naval intelligence effort code-named "Magic" intercepted and decrypted orders alerting affected Japanese units of the tour.

The original message, NTF131755, addressed to the commanders of Base Unit No. 1, the 11th Air Flotilla, and the 26th Air Flotilla, was encoded in the Japanese Naval Cipher JN-25D (Naval Operations Code Book of the third version of RO), and was picked up by three stations of the "Magic" apparatus, including Fleet Radio Unit Pacific Fleet. The message was then deciphered by Navy cryptographers (among them future Supreme Court Justice John Paul Stevens^[1]); it contained time and location details of Yamamoto's itinerary, as well as the number and types of planes that would transport and accompany him on the journey.

Yamamoto, the decryption revealed, would be flying from Rabaul to Balalae Airfield, on an island near Bougainville in the Solomon Islands, on April 18. He and his staff would be flying in two medium bombers (Mitsubishi G4M Bettys of the 205th KōkūtaiNaval Air Unit), escorted by six navy fighters (Mitsubishi A6M Zero fighters of the 204th Kōkūtai NAU), to depart Rabaul at 06:00 and arrive at Ballale at 08:00, Tokyo time.

President Franklin D. Roosevelt ordered Secretary of the Navy Frank Knox to "get Yamamoto." Knox instructed AdmiralChester W. Nimitz of Roosevelt's wishes. Nimitz first consulted Admiral William F. Halsey, Jr., Commander, South Pacific, and then authorized the mission on April 17.

Interception[edit]

To avoid detection by radar and Japanese personnel stationed in the Solomon Islands along a straight-line distance of about 400 miles (640 km) between U.S. forces and Bougainville, the mission entailed an over-water flight south and west of the Solomons. This roundabout approach flight was plotted and measured to be about 600 miles (970 km). The fighters would therefore travel 600 miles out to the target and 400 miles back. The 1,000-mile flight, with extra fuel allotted for combat, was beyond the range of the F4F Wildcat and F4U Corsairfighters then available to Navy and Marine squadrons based onGuadalcanal. The mission was instead assigned to the 339th Fighter Squadron, 347th Fighter Group, whose P-38G aircraft, equipped withdrop tanks, had the range to intercept and engage.

n preparation for the mission, Marine Corps Lt. Col. Luther S. Moore had the P-38s fitted with a Navy ship's compass to aid in navigation at the request of Major John W. Mitchell, commanding the 339th. The fighters each mounted a standard armament of a 20 mmcannon and four 50-caliber (12.7 mm) machine guns, and were equipped to carry two 165-US-gallon (620 L) drop tanks under their wings. A limited supply of 330-US-gallon (1,200 L) tanks were flown up from New Guinea, sufficient to provide each Lightning with one large tank to replace one of the small tanks. Despite the difference in size, the tanks were located close enough to the aircraft's center of gravity to avoid any performance problems.

Eighteen P-38s were tasked for the mission. One flight of four was designated as the "killer" flight while the remainder, which included two spares, would climb to 18,000 feet (5,500 m) to act as "top cover" for the expected reaction by Japanese fighters based at Kahili. A flight plan was prepared by the Command Operations Officer, Marine Major John Condon, but was discarded for one prepared by Mitchell. He calculated an intercept time of 09:35, based on the itinerary, to catch the bombers descending over Bougainville, ten minutes before landing at Balalae. He worked backwards from that time and drew four precisely-calculated legs, with a fifth leg added if Yamamoto did not take the most direct route. In addition to heading out over the Coral Sea, the 339th would "wave-hop" all the way to Bougainville at altitudes no greater than 50 feet (15 m), maintaining radio silence en route.

Although the 339th Fighter Squadron officially carried out the mission, ten of the eighteen pilots were drawn from the other two squadrons of the 347th Group. The Commander AirSols, Rear Admiral Marc A. Mitscher, selected four pilots to be designated as the "killer" flight:

• Capt. Thomas G. Lanphier, Jr.
• Lt. Rex T. Barber
• Lt. Jim McLanahan (dropped out with flat tire)
• Lt. Joe Moore (dropped out with faulty fuel feed)

The remaining pilots would act as reserves and provide air cover against any retaliatory attacks by local Japanese fighters:

• Maj. John Mitchell
• Lt. William Smith
• Lt. Gordon Whittiker
• Lt. Roger Ames
• Capt. Louis Kittel
• Lt. Lawrence Graebner
• Lt. Doug Canning
• Lt. Delton Goerke
• Lt. Julius Jacobson
• Lt. Eldon Stratton
• Lt. Albert Long
• Lt. Everett Anglin
• Lt. Besby F. Holmes (replaced McLanahan)
• Lt. Raymond K. Hine (replaced Moore)

A thorough, detailed briefing included a cover story for the source of the intelligence stating that a coastwatcher had spotted an important high-ranking officer boarding an aircraft at Rabaul, but the pilots were not specifically briefed that their target was Admiral Yamamoto.

The specially-fitted P-38s took off from Kukum Field on Guadalcanal beginning at 07:25. The date, April 18, was the first anniversary of theDoolittle Raid. Two of the Lightnings assigned to the killer flight dropped out of the mission at the start, one with a tire flattened during takeoff (McLanahan) and the second when its drop tanks 

would not feed fuel to the engines (Moore).

In Rabaul, despite urgings by local commanders to cancel the trip for fear of ambush, Yamamoto's airplanes took off as scheduled for the trip of 315 miles (507 km). They climbed to 6,500 feet (2,000 m), with their fighter escort at their 4 o'clock position and 1,500 feet (460 m) higher, split into two V-formations of three planes.

Mitchell's flight of four led the squadron at low altitude, with the killer flight, now consisting of Lanphier, Barber, and spares 1st Lt. Besby F. Holmes and 1st Lt. Raymond K. Hine, immediately behind. Mitchell, fighting off drowsiness, navigated by flight plan and dead reckoning. This proved to be the longest fighter-intercept mission of the war and was so skillfully executed by Mitchell that his force arrived at the intercept point one minute early, at 09:34, just as Yamamoto's aircraft descended into view in a light haze. The P-38s jettisoned the auxiliary tanks, turned to the right to parallel the bombers, and began a full power climb to intercept them.

The tanks on Holmes's P-38 did not detach and his element turned back toward the sea. Mitchell radioed Lanphier and Barber to engage, and they climbed toward the eight aircraft. The nearest escort fighters dropped their own tanks and dived toward the pair of P-38s. Lanphier, in a sound tactical move, immediately turned head-on and climbed towards the escorts while Barber chased the diving bomber transports. Barber banked steeply to turn in behind the bombers and momentarily lost sight of them, but when he regained contact, he was immediately behind one and began firing into its right engine, rearfuselage, and empennage. When Barber hit its left engine, the bomber began to trail heavy black smoke. The Betty rolled violently to the left and Barber narrowly avoided a mid-air collision. Looking back, he saw a column of black smoke and assumed the Betty had crashed into the jungle. Barber headed towards the coast at treetop level, searching for the second bomber, not knowing which one carried the targeted high-ranking officer.

.

arber spotted the second bomber, carrying Chief of Staff Vice AdmiralMatome Ugaki and part of Yamamoto's staff, low over the water off Moila Point, trying to evade an attack by Holmes, whose wing tanks had finally come off. Holmes damaged the right engine of the Betty, which emitted a white vapor trail, but his closure speed carried him and his wingman Hine past the damaged bomber. Barber attacked the crippled bomber and his bullet strikes caused it to shed metal debris that damaged his own aircraft. The bomber descended and crash-landed in the water. Ugaki and two others survived the crash and were later rescued. Barber, Holmes and Hine were attacked by Zeros, Barber's P-38 receiving 104 hits.^[2] Holmes and Barber each claimed a Zero shot down during this melee, although Japanese records show that no Zeros were lost. The top cover briefly engaged reacting Zeros without making any kills. Mitchell observed the column of smoke from Yamamoto's crashed bomber. Hine's P-38 had disappeared by this point, presumably crashed into the water. Running close to minimum fuel levels for return to base, the P-38s broke off contact, with Holmes so short of fuel that he was forced to land in the Russell Islands. Hine was the only pilot who did not return. Lanphier's actions during the battle are unclear as his account was later disputed by other participants, including the Japanese fighter pilots.

As he approached Henderson Field, Lanphier radioed the fighter director on Guadalcanal that "That son of a bitch will not be dictating any peace terms in the White House", breaching security. Immediately on landing (his plane was so short on fuel that one engine quit during landing rollout) he put in a claim for shooting down Yamamoto.

Japanese-American involvement[edit]

Main article: Japanese-American service in World War II

The MIS (Military Intelligence Service), was made of mostly Nisei (Japanese-Americans). They were trained in interpreting, interrogation, and translation with materials ranging from standard textbooks to captured documents, in the war against Japan.^[3]

A major MIS contribution in the Solomons campaign was the ambush of Admiral Isoroku Yamamoto. MIS soldier Harold Fudenna intercepted a radio message indicating the whereabouts of Admiral Yamamoto. Although this message was first met with disbelief, other MIS linguists in Alaska and Hawaii had also intercepted the same message, confirming its accuracy. American forces learned of Yamamoto’s planned flight to Bougainville and on April 18, 1943, Yamamoto’s plane was successfully shot down above Bougainville. There were no survivors. General Douglas MacArthur referred to this incident as “one of the singularly most significant actions of the Pacific War.”^[4]

Who shot down Yamamoto?[edit]

Although Operation Vengeance was one of the most expertly-executed missions in American air force history, the whole episode has subsequently been overshadowed by controversy over who actually shot down the admiral's aircraft. The issue began immediately after the mission when the US military quickly credited Thomas Lanphier with the kill. The captain claimed in his report back at Guadalcanal that after turning to engage the escort Zeroes and shooting the wings off one, he had flipped upside down as he circled back towards the two bombers. On seeing the lead bomber turning in a circle below him, he came out of his turn at a right angle to the circling bomber and fired blowing off its right wing. The plane then crashed into the jungle. Lanphier also reported that he witnessed Lt. Rex Barber shoot down another bomber which also crashed into the jungle.