High Quality Content by WIKIPEDIA articles! Seaboard World Airlines Flight 253A was a military charter flight carrying 214 American troops bound for Vietnam. On July 1, 1968, the plane was intercepted by Soviet jets after it unintentionally violated Soviet airspace. It was forced to land on one of the Soviet-controlled Kuril Islands with all 238 Americans aboard being detained for two days. The incident was a diplomatic embarrassment for the United States.