page_title: 40th Air Expeditionary Wing
section_title: World War II
hierarchical_section_title: 40th Air Expeditionary Wing / History / World War II
caption_attribution_description: English: 40th Bombardment Group B-29 42-6310 taking off from Chakulia, India, June, 1944
context_page_description: The United States Air Force's 40th Air Expeditionary Wing was an Air expeditionary unit located at Diego Garcia, in the Indian Ocean, from 2001 to c. 2006.
  Its predecessor unit, the United States Army Air Forces 40th Bombardment Group was part of Twentieth Air Force during World War II. The unit served primarily in the Pacific Ocean theater and China Burma India Theater of World War II. The 40th Bomb Group's aircraft engaged in very heavy bombardment B-29 Superfortress operations against Japan. Its aircraft were identified by Triangle "S".
  In the postwar era, the 40th Bombardment Group was one of the original ten USAAF bombardment groups assigned to Strategic Air Command on 21 March 1946, however it was inactivated due to budget constraints on 1 August 1946. The unit was reactivated and elevated to Wing status in 1952 as a SAC B-47 Stratojet organization until the phaseout of the aircraft in 1964. Reactivated as a USAFE wing to be the host unit at Aviano Air Base, Italy in 1966 to provide support to Tactical Air Command deployed rotational elements until 1992.
context_section_description: The 40th Bombardment Group was constituted in Puerto Rico on 22 November 1940 and activated on 1 April 1941. The unit's operational squadrons (29th, 44th and 45th) were equipped with Douglas B-18 Bolos then early B-17 Flying Fortresses and B-26 Marauder aircraft to train, and patrol the Caribbean area, later to provide air defense of the Panama Canal after the Japanese attack on Pearl Harbor.
  With the diminished need for a Caribbean defense, the 40th was reassigned back to the United States and redesignated the 40th Bombardment Group (Very Heavy) in November 1943, being assigned to Pratt Army Airfield, Kansas and to the first B-29 Superfortress wing, the 58th Bombardment Wing. At Pratt, the group's squadrons (25th 44th, 45th, and 395th) engaged in transition training on the new aircraft and its new mission.
  In March 1944, the group left the United States and deployed to a former B-24 Liberator airfield at Chakulia, India. In India, the group was assigned to the XX Bombardment Command of the new Twentieth Air Force. During the week of 15–22 April, no less than five 58th Bomb Wing B-29s crashed near Karachi all from overheated engines. The entire Wing had to be grounded en route until the cause was found. The cause was traced to the fact that the B-29's R-3350 engine had not been designed to operate at ground temperatures higher than 115 °F (46 °C), which were typically exceeded in India. Modifications had also to be made to the aircraft and after these modifications, B-29 flights to India were resumed.
  From India, the 40th Bomb Group planned to fly missions against Japan from airfields in China. However, all the supplies of fuel, bombs, and spares needed to support the forward bases in China had to be flown in from India over "The Hump" (the name given by Allied pilots to the eastern end of the Himalayan Mountains), since Japanese control of the seas around the Chinese coast made seaborne supply of China impossible. Many of the supplies had to be delivered to China by the B-29s themselves. For this role, they were stripped of nearly all combat equipment and used as flying tankers and each carried seven tons of fuel. The Hump route was so dangerous and difficult that each time a B-29 flew from India to China it was counted as a combat mission,
  The first combat mission by the group took place on 5 June 1944 when squadrons of the 40th took off from India to attack the Makasan railroad yards at Bangkok, Thailand. This involved a 2261-mile round trip, the longest bombing mission yet attempted during the war.
  On 15 June the group participated in the first American Air Force attack on the Japanese Home Islands since the Doolittle raid in 1942 when it took part in the bombing of Yawata. Operating from bases in India, and at times staging through fields in China, the group struck such targets as transportation centers, naval installations, iron works, and aircraft plants in Burma, Thailand, China, Japan, Indonesia, and Formosa, receiving a Distinguished Unit Citation for bombing iron and steel works at Yawata, Japan, on 20 August 1944. From a staging field in Ceylon, the 40th mined waters near the port of Palembang, Sumatra, in August 1944.
  The group was reassigned to Tinian, in the Marianas February–April 1945, for further operations against Japan with the XXI Bomb Command. The 40th made daylight attacks from high altitude on strategic targets, participated in incendiary raids on urban areas, and dropped mines in Japanese shipping lanes. Received a Distinguished Unit Citation for attacking naval aircraft factories at Kure, oil storage facilities at Oshima, and the industrial area of Nagoya, in May 1945. Raided light metal industries in Osaka in July 1945, being awarded another DUC for this mission.
  After V-J Day, the group dropped food and supplies to Allied prisoners in Japan, Korea, and Formosa, and took part in show-of-force missions.
caption: 42-6310 taking off from Chakulia, India, June 1944
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