1503d Air Transport Group The 1503d Air Transport Group is an inactive United States Air Force unit . Its last was assigned to the 1502d Air Transport Wing , Military Air Transport Service , stationed at Tachikawa Air Base , Japan . It was inactivated on 8 January 1966 With the disestablishment of MATS , the assets of the unit at Tachikawa were reassigned to the 6100th Support Wing , Pacific Air Forces . History . The unit was initially formed at Tachikawa AAB , Japan in 1946 with a mission to provide transportation for priority passengers and cargo in and around the Tokyo Area ; to support the Occupation Government in Japan , and provide strategic transport to the United States . Tachikawa was initially occupied by Army forces on 5 September 1945 . At the time the runway was unusable due to heavy bombardment during 1944 and 1945 by the USAAF XXI Bomber Command B - 29 Superfortress bombers which heavily damaged the Tachikawa Aircraft manufacturing facilities , of which the airfield was a part of prior to the occupation . By 1 January 1946 the base was cleaned up enough to permit Air Transport Command C - 47 Skytrain and C - 46 Commando aircraft to operate from the base , ATC established the 1503d AAF Base Unit to manage the cargo and personnel operations at the airfield . Larger C - 54 Skymaster s began using the base by April 1946 , and a day / night lighting system was installed and in operation by November 1946 . In 1947 , Air Transport Command began to support the Seventh Air Force Service Command Japan Air Material Area ( JAMA ) at Tachikawa , which eventually became the major tenant unit at the base , and by 1948 was providing depot - level maintenance for aircraft in Far East Air Force and logistical support from Air Materiel Command . In July 1949 , JAMA was redesignated Far East Air Material Command ( FEAMCOM ) . With the inactvation of Air Transport Command in 1948 , Military Air Transport Service redesignated the 1503d AAFBU the 540th Air Transport Wing , later 1503d Air Transport Wing . The wing became the host organization at Tachikawa Air Force Base upon activation . The 1503d ATW became the main MATS organization in the Western Pacific , supporting numerous tenant organizations such as the Air Rescue Service ; Air Weather Service , and Far East Air Force theater Troop Carrier Groups ( later Wings ) which transshipped supplies and personnel from the MATS Aerial Port at Tachikawa throughout the 1950s . The first major mission by the 1503d was the evacuation of large numbers of Americans out of China in 1948 after the Communists defeated the Chinese Nationalist forces during the Chinese Civil War . The Korean War saw operations increase , with Troop Carrier units carrying out the evacuation of American civilians and then transporting the torrent of Allied military men and material flowing into the war zone . Around the clock planes arrived and departed . A typical flight might carry 35 , 000 pounds of hand grenades to South Korea , with 80 wounded personnel arriving to be transported to the USAF Hospital on the base . For thousands of servicemen whose tours took them into , through or out of Tachikawa , the USAF hospital became the best barometer of American military activities in the Far East . MATS flights arriving on C - 118 , C - 121 , C - 124 , and later C - 135 jet transports from Hickam Field , Hawaii or being staged through Alaska . From Tachikawa , outbound MATS flights headed to Clark Air Base heading to Saigon , Bangkok , and on to Karachi Airport , Pakistan or to Guam , Wake or Midway Island in the Central Pacific Region . As United States military forces began to increase in Indochina , more and more equipment moved into first Tan Son Nhut Air Base in South Vietnam , then to Don Muang Royal Thai Air Force Base , near Bangkok , and in early 1965 to the huge new Cam Ranh Air Base with the jet C - 141 Starlifter transports . In 1964 , operations from Tachikawa began to phase down as its location in the urban area of Tokyo made heavy transport operations undesirable , with more and more heavy transport operations going to Yokota Air Base . The 1503d was reduced to Group Level , and focused more on Aeromedical Transport operations from the Philippines , and supporting MATS units at deployed locations in the Pacific . With the inactivation of the Military Air Transport Service in 1966 , the aerial port facilities were turned over to the Pacific Air Forces 6100th Support Wing , which had taken over base support duties from the 1503d ATW in 1953 . Military Airlift Command operations were reassigned to Yokota Air Base .