On 23 March 1973 the USAF airlift control center at Tan Son Nhut Air Base moved to U-Tapao becoming the Pacific Transportation Management Agency, Thailand, responsible for all C-130 operations in Southeast Asia. U-Tapao based C-130s of the 374th Wing flew missions into Cambodia, South Vietnam, and a weekly flight to Hanoi in support of the International Commission of Control and Supervision until April 1975. The C-130s flew supply missions into Cambodia until May 1974 when these operations were taken over by BirdAir which operated under contract to the US Government. In addition Khmer Air Force C-123s also began flying supply missions from U-Tapao into bases in Cambodia.