Twentieth Air Force


The Twentieth Air Force is a numbered air force of the United States Air Force Global Strike Command. It is headquartered at Francis E. Warren Air Force Base, Wyoming.
20 AF's primary mission is intercontinental ballistic missile operations. The Twentieth Air Force commander is also the Commander, Task Force 214, which provides alert ICBMs to the United States Strategic Command.
Established on 4 April 1944 at Washington D.C, 20 AF was a United States Army Air Forces combat air force deployed to the Pacific Theater of World War II. Operating initially from bases in India and staging through bases in China, 20 AF conducted strategic bombardment of the Japanese Home Islands. It relocated to the Mariana Islands in late 1944, and continued the strategic bombardment campaign against Japan until the Japanese capitulation in August 1945. The 20 AF 509th Composite Group conducted the atomic attacks on Hiroshima and Nagasaki in August 1945, and remains as the only air force organization to have used a nuclear weapon in combat.
Inactivated on 1 March 1955, the command was reactivated 1 September 1991, as a component of the Strategic Air Command and became operationally responsible for all land-based Intercontinental Ballistic Missiles.

Overview

Twentieth Air Force headquarters is unique in that it has dual responsibilities to Air Force Global Strike Command and United States Strategic Command. As the missile Numbered Air Force for AFGSC, 20th Air Force is responsible for maintaining and operating the Air Force's ICBM force. Designated as STRATCOM's Task Force 214, 20th Air Force provides on-alert, combat ready ICBMs to the president. Combined with the other two legs of the Triad, bombers and submarines, STRATCOM forces protect the United States with an umbrella of deterrence.

Organization

The Twentieth Air Force was brought into existence on 4 April 1944 specifically to perform strategic bombardment missions against Japan. This was done at the insistence of General Henry H. Arnold, commander of the USAAF, mainly to avoid having the new B-29 Superfortress being diverted to tactical missions under pressure from the China Burma India Theater commanders. Twentieth Air Force was to be commanded by General Arnold himself at Joint Chiefs of Staff level. Twentieth Air Force was completely autonomous and its B-29s were to be completely independent of other command structures and would be dedicated exclusively against strategic targets in Japan.
In addition Twentieth Air Force was chosen to be the operational component of the Manhattan Project in 1944, and performed the atomic attacks on Japan in August 1945. However, in early 1944, the B-29 was not yet operationally ready. The aircraft had been in development at Boeing since the late 1930s and the first XB-29 flew on 21 September 1942. However, the aircraft suffered from an overwhelming number of development issues, and with engine problems. As a result, most of the first production B-29s were still held up at Air Technical Service Command modification centers, awaiting modifications and conversion to full combat readiness. By March 1944, the B-29 modification program had fallen into complete chaos, with absolutely no bombers being considered as combat ready. The program was seriously hampered by the need to work in the open air in inclement weather, as many hangars were simply too small to house the aircraft indoors; by delays in acquiring the necessary tools and support equipment, and by the USAAF's general lack of experience with the B-29.
General Arnold became alarmed at the situation and directed that his assistant, Major General B. E. Meyer, personally take charge of the entire modification program. The resulting burst of activity that took place between 10 March and 15 April 1944 came to be known as the "Battle of Kansas". Beginning in mid-March, technicians and specialists from the Boeing Wichita and Seattle factories were drafted into the modification centers to work around the clock to get the B-29s ready for combat. The mechanics often had to work outdoors in freezing weather. As a result of superhuman efforts on the part of all concerned, 150 B-29s had been handed over to the XX Bomber Command by 15 April 1944.

World War II operations

Operations from CBI Theater

Operation Matterhorn was the name for the B-29 Superfortress offensive against the Empire of Japan from airfields in China. On 10 April 1944, the Joint Chiefs of Staff informally approved Operation Matterhorn. The operational vehicle was to be the 58th Bombardment Wing of the XX Bomber Command.
The headquarters of the XX Bomber Command had been established at Kharagpur India on 28 March 1944. The commander was General Kenneth B. Wolfe. The first B-29 reached its base in India on 2 April 1944. In India, existing airfields at Kharagpur, Chakulia, Piardoba and Dudkhundi had been converted for B-29 use. All of these bases were located in southern Bengal and were not far from port facilities at Calcutta.
The first B-29 bombing raid from India took place on 5 June 1944. Ninety-eight B-29s took off from bases in eastern India to attack the Makasan railroad yards at Bangkok, Thailand. Bombardment operations against Japan were planned to be carried out from bases in China. There were four sites in the Chengtu area of China that were assigned to the B-29 operation—at Kwanghan, Kuinglai, Hsinching, and Pengshan. The primary flaw in the Operation Matterhorn plan was that 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, since Japanese control of the seas around the Chinese coast made seaborne supply of China impossible.
By mid-June, enough supplies had been stockpiled at Chinese forward bases to permit the launching of a single attack against targets in Japan. It was a nighttime raid to be carried out on the night of 14/15 June 1944 against the Imperial Iron and Steel Works at Yawata on Kyūshū. Unfortunately, the Japanese had been warned of the approaching raid and the city of Yawata was blacked out and haze and/or smoke helped to obscure the target. Only 15 aircraft bombed visually while 32 bombed by radar. Only one bomb actually hit anywhere near the intended target, and the steel industry was essentially untouched. Although very little damage was actually done, the Yawata raid was hailed as a great victory in the American press, since it was the first time since the Doolittle raid of April 1942 that American aircraft had hit the Japanese home islands.
On the night 10–11 August, 56 B-29s staged through British air bases in Ceylon attacked the Plajdoe oil storage facilities at Palembang on Sumatra in Indonesia. This involved a 4030-mile, 19-hour mission from Ceylon to Sumatra, the longest American air raid of the war. Other B-29s laid mines in the Moesi River. At the same time, a third batch of B-29s attacked targets in Nagasaki. These raids all showed a lack of operational control and inadequate combat techniques, drifting from target to target without a central plan and were largely ineffective.
In Washington, it was decided that new leadership was needed for Twentieth Air Force. General Wolfe's replacement was Major General Curtis E. LeMay, who arrived in India on 29 August. Supply problems and aircraft accidents were still preventing a fully effective concentration of force and effort. In addition, Japanese defensive efforts were becoming more effective.
By late 1944, it was becoming apparent that B-29 operations against Japan staged out of bases in China and India were far too expensive in men and materials and would have to be stopped. In December 1944, the Joint Chiefs of Staff made the decision that Operation Matterhorn would be phased out, and the 58th Bombardment Wing's B-29s would be moved to newly captured bases in the Marianas in the central Pacific. The last raid out of China was flown on 15 January 1945, which was an attack on targets in Formosa. The 58th Bombardment Wing then redeployed to new bases in the Marianas in February.

Attacks on Japan from the Marianas

File:B-29s-japan-1945.jpg|thumb|73d Bombardment Wing, 498th Bombardment Group B-29s flying near Mount Fuji, Japan, 1945
The Marianas chain of islands, consisting primarily of Saipan, Tinian, and Guam, were considered as being ideal bases from which to launch B-29 Superfortress operations against Japan. The islands were about 1500 miles from Tokyo, a range which the B-29s could just about manage. Most important of all, they could be put on a direct supply line from the United States by ship. The XXI Bombardment Command had been assigned the overall responsibility of the B-29 operations out of the Marianas bases.
The first B-29 arrived on Saipan on 12 October 1944. It was piloted by General Hansell himself. By 22 November, over 100 B-29s were on Saipan. The XXI Bomber Command was assigned the task of destroying the aircraft industry of Japan in a series of high-altitude, daylight precision attacks.
The first raid against Japan took place on 24 November 1944. The target was the Nakajima Aircraft Company's Musashi engine plant just outside Tokyo. 111 B-29s took off, Seventeen of them had to abort due to the usual spate of engine failures. The remainder approached the target at altitudes of 27–32,000 feet. For the first time, the B-29 encountered the jet stream, which was a high-speed wind coming out of the west at speeds as high as 200 mph at precisely the altitudes at which the bombers were operating. This caused the bomber formations to be disrupted and made accurate bombing impossible.
Concerned about the relative failure of the B-29 offensive to deal any crippling blows to Japan, General LeMay issued a new directive on 19 February. General LeMay had analyzed the structure of the Japanese economy, which depended heavily on cottage industries housed in cities close to major industrial areas. By destroying these feeder industries, the flow of vital components to the central plants could be slowed, disorganizing production of weapons vital to Japan. He decided to do this by using incendiary bombs rather than purely high-explosive bombs, which would, it was hoped, cause general conflagrations in large cities like Tokyo or Nagoya, spreading to some of the priority targets.
The first raid to use these new techniques was on the night of 9–10 March against Tokyo. Another wing—the 314th Bombardment Wing commanded by Brig. Gen. Thomas S. Power—had arrived in the Marianas and was stationed at North Field on Guam. A total of 302 B-29s participated in the raid, with 279 arriving over the target. The raid was led by special pathfinder crews who marked central aiming points. It lasted for two hours. The raid was a success beyond General LeMay's wildest expectations. The individual fires caused by the bombs joined to create a general conflagration due to strong winds of some 17 to 28 mph at ground level, that prevented a more specific firestorm event. When it was over, sixteen square miles of the center of Tokyo had gone up in flames and nearly 84,000 people had been killed. Fourteen B-29s were lost. The B-29 was finally beginning to have an effect.
By mid-June, most of the larger Japanese cities had been gutted, and LeMay ordered new incendiary raids against 58 smaller Japanese cities. By now, the B-29 raids were essentially unopposed by Japanese fighters. In late June, B-29 crews felt sufficiently confident that they began to drop leaflets warning the population of forthcoming attacks, followed three days later by a raid in which the specified urban area was devastated. By the end of June, the civilian population began to show signs of panic, and the Imperial Cabinet first began to consider negotiating an end to the war. However, at that time, the Japanese military was adamant about continuing on to the bitter end.
In June 1945, the XX and XXI Bombardment Commands were grouped under the U.S. Strategic Air Forces in the Pacific, under the command of General Carl A. Spaatz. The history of XXI Bomber Command terminated on 16 July 1945. On that date the command was redesignated Headquarters and Headquarters Squadron, Twentieth Air Force. This redesignation brought to an end the XXI Bomber Command as a separate establishment, as it was absorbed into the internal organizational structure of Twentieth Air Force and was placed under the command of USASTAF.