T1-323 was the tail number (T1 = "705 Kōkūtai") of the plane carrying Japanese Admiral Isoroku Yamamoto on an inspection tour throughout the South Pacific when he was shot down and killed by American fighter aircraft during World War II. On 18 April 1943, T1-323, a Mitsubishi G4M1 (model 11) "Betty" long-range bomber, and a sister craft departed from Rabaul, were headed to Bougainville in the Solomon Islands off New Guinea, when a task group of P-38s intercepted and downed the planes over Buin, a large Japanese army base in southern Bougainville.