18 avril 1943
Le 29 janvier 1943, la corvette néo-zélandaise Kiwi éperonne et coula un sous-marin japonais aux environs de Guadalcanal. A bord du sous-marin se trouvent les nouveaux codes japonais, connus sous le nom de JN25. A partir de ce jour, les américains sont en mesure de décoder tous les messages japonais, y compris celui de la visite de l'amiral Yamamoto aux troupes des Salomons. Toutes les informations importantes s'y trouvent : route, escorte, etc.. Ayant tous les atouts en mains, il est décidé d'essayer d'abattre l'amiral Yamamoto, dont la popularité et le génie militaire ne sont plus à prouver.
Le 339ème escadrille de chasse basée à Guadalcanal reçoit de Nimitz l'ordre d'intercepter l'avion de l'amiral Yamamoto. Seuls les P-38 munis de réservoirs supplémentaires peuvent mener cette mission à bien.
Récit du Col. John Mitchell, leader de la mission :
Nous allions devoir voler pendant 435 miles sans le moindre repère, jusqu'à Bougainville ce qui représentait la plus longue interception de ma carrière. Quelle chance avions nous de rencontrer notre cible après une telle distance à 3000 mètres. Il n'est jamais facile d'arriver à l'heure à un rendez-vous avec quelqu'un qui risque de venir.
Notre vol allait être le suivant :
> On 29 January 1943, the New Zealand Corvette, Kiwi rammed and sank a
> Japanese submarine of Guadalcanal. Aboard the submarine were 20,000
> codebooks containing a new version of the Japanese Naval code, known as
> JN25. Because this code might have fallen into Allied hands, the
> Japanese Navy were forced to used a reserve version of the code that was
> simpler. Besides being simpler, much of the code was already known to
> American cryptographers and was incorporated in a automatic decoding
> machine that, using punched cards, could decode around half of most
> messages before human intervention was needed. As there were less than
> dozen people in America who could speak Japanese and who had the
> security clearance to work on codebreaking, this was an important factor
> in decoding any message.
> This chain of events lead to American Combat Intelligence being able to
> decode a message that Admiral Yamamoto was planning a one-day morale
> boosting tour of the Upper Solomon Islands. His complete route was
> given, with details of his escort. After some consideration, involving
> the President himself, it was decided to try to kill Yamamoto. He was
> expected to arrive in a Betty bomber at 8:00 am on 18th April at
> Ballale, escorted by six Zero fighters. Flying from Henderson Airfield
> the new P38 just about had the range to make the intercept. However,
> although Yamamoto was known to be punctual, making contact at an exact
> time, flying from different directions and starting 400 miles away, the
> Americans had a fairly low chance of success.
> Captain John Mitchell was in charge of the operation and Tom Lanphier
> was detailed to make the kill. Taking off at 6:25 am, they arrived at
> the rendezvous at 7:44 am, about one minute early, which was a
> remarkable feat of navigation. It was hazy and Mitchell had difficulty
> in seeing the land. However, when he did he also saw two Betty bombers
> almost on collision course. Tom Lanphier reported on the incident:
> 'The lead bomber dived down and away. I wanted to get after this fellow
> but it was already apparent I couldn't get to him unless I did something
> about the three fighters coming up at me. I started firing long before I
> should have. I was frightened. I just started shooting with the machine
> gun. And this fellow's wing came off and he went under. And the other
> two fighters went on either side of me. So I flipped over and the bomber
> which had dived down was coming back and around, so I started down after
> him. It was already down on the tree tops, the one I was after - the
> lead one - and I was going too fast at the time to shoot him. So I
> started skidding around to slow up and in order to be sure my guns were
> working again I fired them, testing them. At the moment I tested them -
> I hit him.
> If 'd waited till I was ready to shoot, I'd have missed him. But I fired
> this thing and his right engine started to burn and the bomber went down
> in the jungle; just plunged down in a big burst of flame.'
> Tokyo radio did not report the death until four weeks later.
> Colin Bignell