Key Point: The downing of Admiral Isoroku Yamamoto is arguably the most studied fighter engagement of the Pacific War.
When American air ace Major John Mitchell led 16 Lockheed P-38 Lightning fighters on the longest combat mission yet flown (420 miles) on April 18, 1943, Mitchell’s target was the Japanese admiral considered the architect of the Pearl Harbor attack.
Mitchell’s P-38 pilots, using secrets from broken Japanese codes, were going after Isoroku Yamamoto, the poker-playing, Harvard-educated naval genius of Japan’s war effort. Mitchell’s P-38s intercepted and shot down the Mitsubishi G4M “Betty” bomber carrying Yamamoto. After the admiral’s death, Japan never again won a major battle in the Pacific War.
No band of brothers ever worked together better than the men who planned, supported, and flew the Yamamoto mission. Yet, after the war, veterans fell to bickering over which P-38 pilot actually pulled the trigger on Yamamoto.
One thing they never disagreed on. Like most young pilots of their era, they believed the P-38 Lightning was the greatest fighter of its time.
Roger J. Ames (1919-2000) flew the Yamamoto mission. This first-person account by Ames was recorded by the author in 1998 and appeared in his 2007 book, Air Combat: A History of Fighter Pilots; it has never before appeared in a magazine.
Intercepting a Crucial Japanese Radio Message
The downing of Admiral Isoroku Yamamoto is arguably the most studied fighter engagement of the Pacific War. Yamamoto, 56, was commander in chief of the Japanese Combined Fleet and the architect of the Pearl Harbor attack. He called himself the sword of Japan’s Emperor Hirohito. He claimed he was going to ride down Pennsylvania Avenue on a white horse and dictate the surrender of the United States in the White House.
Yamamoto studied at Harvard (1919-1921), traveled around America, was twice naval attaché in Washington, D.C., and understood as much about the United States, including U.S. industrial power, as any Japanese leader. In April 1943, Yamamoto was trying to prevent the Allies from taking the offensive in the South Pacific and was visiting Japanese troops in the Bougainville area.
On the afternoon of April 17, 1943, Major John Mitchell, commander of the 339th Fighter Squadron, was ordered to report to our operations dugout at Henderson Field on Guadalcanal. The 1st Marine Division had captured the nearly completed field the previous summer and named it for Major Lofton Henderson, the first Marine pilot killed in action in World War II when his squadron engaged the Japanese fleet that was attacking Midway.
Now Mitchell found himself surrounded by high-ranking officers. They told him the United States had broken the Japanese code and had intercepted a radio message advising Japanese units in the area that Yamamoto was going on an inspection trip of the Bougainville area.
The message gave Yamamoto’s exact itinerary and pointed out that the admiral was most punctual. They told Mitchell that Frank Knox, secretary of the Navy, had held a midnight meeting with President Franklin D. Roosevelt regarding the intercepted message. It was decided that we would try to get Yamamoto if we could. The report of the meeting was probably inaccurate because Roosevelt was on a rail trip away from Washington, but the plan to get Yamamoto unquestionably began at the top.
Eighteen P-38s Selected For the Mission
The Navy would never have admitted it, but the Army’s P-38 was the only fighter with the range to make the approximately 1,100-mile round trip. We were under the command of the Navy at Guadalcanal, so you can bet they’d have taken the job if they were able.
According to the intercepted message, Yamamoto and his senior officers were arriving at the tiny island of Ballale just off the coast of Bougainville at 9:45 the next morning. The message said that Yamamoto and his staff would be flying in Mitsubishi G4M “Betty” bombers, escorted by six Zeros. The Yamamoto trip was to include a visit to Shortland Island and Bougainville.
Mitchell was to be mission commander of 18 P-38s that would intercept, attack, and destroy the bombers. That’s all the P-38s we had in commission.
The Plan of Attack
Led by Mitchell, we planned the flight in excruciating detail. Nothing was left to chance. Yamamoto was to be at the Ballale airstrip just off Bougainville at 9:45 the next morning and we planned to intercept him 10 minutes earlier about 30 miles out. To ensure complete surprise, we planned a low level, circuitous route staying below the horizon from the islands we had to bypass, because the Japanese had radar and coastwatchers just as we did.
We plotted the course and timed it so that the interception would take place upon the approach of the P-38s to the southwestern coast of Bougainville at the designated time of 9:35 am. Each minute detail was discussed, and nothing was taken for granted. Takeoff procedure, flight course and altitude, radio silence, when to drop belly tanks, the tremendous importance of precise timing and the position of the covering element: all were discussed and explained until Mitchell was sure that each of his pilots knew his part and the parts of the other pilots from takeoff to return.
Mitchell chose pilots from the 12th, 70th, and 339th Fighter Squadrons. These were the only P-38 squadrons on Guadalcanal. The only belly tanks we had on Guadalcanal were 165-gallon tanks, so we had to send to Port Moresby for a supply of the larger 310-gallon tanks. We put one tank of each size on each plane. This gave us enough fuel to fly to the target area, stay in the area where we expected the admiral for about 15 minutes, fight, and come home. The larger fuel tanks were flown in that night, and ground crews worked all night getting them installed along with a Navy compass in Mitchell’s plane.
Four of our pilots were designated to act as the “killer section” with the remainder as their protection. Mitchell said that if he had known there were going to be two bombers in the flight he would have assigned more men to the killer section. The word for bomber and bombers is the same in Japanese. (Author’s note: Ames is incorrect on this point about the Japanese language).
Captain Thomas G. Lanphier, Jr., led the killer section. His wingman was 1st Lt. Rex T. Barber. 1st Lt. Besby F. “Frank” Holmes led the second element. His wingman was 1st Lt. Raymond K. Hine.
The cover section was led by Mitchell and included myself and 11 other pilots. Eight of the 16 pilots on the mission were from the 12th Fighter Squadron, which was my squadron.
Although 18 P-38s were scheduled to go on the mission, only 16 were able to participate because one plane blew a tire on the runway on takeoff and another’s belly tanks failed to feed properly.
“Bogeys! Eleven O’Clock, High!”
It was Palm Sunday, April 18, 1943. But since there were no religious holidays on Guadalcanal, we took off at 7:15 am, joined in formation, and left the island at 7:30 am, just two hours and five minutes before the planned interception. It was an uneventful flight but a hot one, at from 10 to 50 feet above the water all the way. Some of the pilots counted sharks. One counted pieces of driftwood. I don’t remember doing anything but sweating. Mitchell said he may have dozed off on a couple of occasions but received a light tap from “The Man Upstairs” to keep him awake.
Mitchell kept us on course flying the five legs by compass, time, and airspeed only. As we turned into the coast of Bougainville and started to gain altitude, after more than two hours of complete radio silence, 1st Lt. Douglas S. Canning––Old Eagle Eyes–– uttered a subdued “Bogeys! Eleven o’clock, high!” It was 9:35 am. The admiral was precisely on schedule, and so were we. It was almost as if the affair had been prearranged with the mutual consent of friend and foe. Two Betty bombers were at 4,000 feet with six Zeros at about 1,500 feet higher, above and just behind the bombers in a “V” formation of three planes on each side of the bombers.
We dropped our belly tanks. We put our throttles to the firewall and went for altitude. The killer section closed in for the attack while the cover section stationed themselves at about 18,000 feet to take care of the expected fighters from Kahili. As Mitchell said, “The night before we knew the Japanese had 75 Zeros on Bougainville and I wanted to be where the action was.
I thought, “Well, I’m going on up higher and we’re going to be up there and have a turkey shoot.’” We expected from 50 to 75 Zeros should be there to protect Yamamoto just as we had protected Secretary of the Navy Frank Knox when he came to visit a couple of weeks before. We’d had as many fighters in the air to protect Knox as we could get off the ground. I guess the Japanese had all their fighters lined up on the runway for inspection. Anyway, none of the Zeros came up to meet us. Our intercept force encountered only the Zeros that were escorting Yamamoto.
This Man’s Assassination Was Key to Complete American Victory is written by Warfare History Network for nationalinterest.org