505th Bombardment Group
The 505th Bombardment Group was a United States heavy-bomber unit that conducted B-29 operations against Japan during the Pacific campaign of World War II.
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Overview
The 505th Bombardment Group was an inactive United States military aviation unit formed during World War II for very-heavy bombardment operations. Constituted on 28 February 1944 and activated on 11 March 1944, it was organized around Boeing B-29 Superfortress operations and ultimately served in the Pacific Ocean theater under the Twentieth Air Force and the 313th Bombardment Wing. Its last assignment was with the Thirteenth Air Force, and it was inactivated at Clark Field in the Philippines on 30 June 1946. The group began its preparation in the United States. It was activated at Dalhart Army Air Field, Texas, drawing its initial cadre from the 9th Bombardment Group. On 1 April 1944 it moved to Harvard Army Air Field, Nebraska. Because B-29 aircraft were not initially available in sufficient numbers, the group used Boeing B-17 Flying Fortresses for part of its training. Its organization was also adjusted during this period: on 1 May 1944, it changed from four squadrons of seven aircraft to three squadrons of ten aircraft. The 482d, 483d, and 484th Bombardment Squadrons remained with the group through inactivation, while the 485th Bombardment Squadron left in May 1944. After completing its preparation, the group departed Harvard on 6 November 1944. Its ground echelon sailed from Seattle for the Pacific, while its air echelon moved through Hamilton and Mather Fields in California with the group's B-29s. The unit reached North Field on Tinian in the Mariana Islands on 19 December 1944 and began theater training almost immediately. Its first combat mission took place on 24 January 1945, striking targets associated with Iwo Jima and the Truk Islands. The 505th initially flew high-altitude daylight missions against Japanese industrial and military targets. On 10 February 1945 it attacked the Nakajima Aircraft Company plant at Ota. Eighteen of the group's B-29s participated, although eight aircraft were lost, principally because of operational difficulties. The mission earned the group a Distinguished Unit Citation. As the limitations of high-altitude precision bombing became increasingly apparent, XXI Bomber Command shifted toward low-altitude nighttime incendiary attacks. The 505th participated in this wider area-bombing campaign from March through the end of the war. During April 1945, the group also supported the invasion of Okinawa, known as Operation Iceberg. It attacked Japanese airfields at Miyazaki and Kanoya on Kyushu, bases used to launch kamikaze operations against Allied forces. These attacks disrupted the bases and compelled Japan to retain fighter defenses in the area. The group also conducted aerial mining against Japanese shipping. Beginning on 27 March, it became the only XXI Bomber Command group to undertake this mission. From 17 June to 1 July it concentrated on mining the Shimonoseki Strait and ports in the Inland Sea, an operation that resulted in a second Distinguished Unit Citation. The group's final combat mission was flown during the night of 14–15 August 1945. After Japan's surrender, its aircraft delivered relief supplies to Allied prisoner-of-war camps and performed show-of-force and bomb-damage-assessment flights over Japan. The group moved from Tinian to Clark Field in Luzon, Philippines, in March 1946 and was inactivated there on 30 June 1946. It is therefore best understood as a historical military unit rather than a commercial brand, with its identity associated primarily with B-29 strategic bombing, Okinawa support, aerial mining, and postwar relief operations.
History
The 505th Bombardment Group was constituted as a very-heavy bombardment group on 28 February 1944 and activated at Dalhart Army Air Field, Texas, on 11 March. Its initial cadre came from the 9th Bombardment Group. The unit moved to Harvard Army Air Field, Nebraska, on 1 April, where it developed the personnel, maintenance organization, and aircrew proficiency required for long-range B-29 operations. During the early training period, it used B-17 Flying Fortresses because operational B-29s were not yet available. On 1 May the group was reorganized from four seven-aircraft squadrons into three ten-aircraft squadrons. The 482d, 483d, and 484th Bombardment Squadrons continued with the group, while the 485th departed on 10 May. The group left Harvard on 6 November 1944. Its ground personnel traveled from Seattle to the Pacific, and its aircraft and aircrews staged through Hamilton and Mather Fields in California. The unit arrived at North Field, Tinian, on 19 December 1944 as part of the B-29 force operating from the Mariana Islands. It began theater training and flew its first combat mission on 24 January 1945, attacking targets associated with Iwo Jima and Truk. Initially, the 505th participated in high-altitude daylight precision bombing against Japanese industrial and military facilities. Its 10 February attack on the Nakajima Aircraft Company plant at Ota involved eighteen group aircraft. Despite severe losses, the operation earned a Distinguished Unit Citation. The broader B-29 campaign subsequently moved toward lower-altitude nighttime incendiary attacks because high-altitude weather, jet-stream conditions, enemy defenses, and bombing accuracy limited the effectiveness of earlier methods. The 505th joined this area-bombing campaign through the summer of 1945. The unit's missions were not limited to Japan's principal urban and industrial centers. During the Okinawa campaign, it attacked the Kyushu airfields at Miyazaki and Kanoya, which supported kamikaze operations against Allied naval and ground forces. By striking those bases and requiring Japan to maintain fighter defenses, the group's operations supported the wider effort to secure air superiority over Okinawa. The 505th also had a distinctive role in aerial mining. It began mining operations on 27 March 1945 and was the only group in XXI Bomber Command to perform that mission. Mining became a major focus from 17 June through 1 July, when the group laid mines in the Shimonoseki Strait and harbors of the Inland Sea. This campaign earned a second Distinguished Unit Citation. Its final combat mission took place on the night of 14–15 August, shortly before Japan's surrender. After V-J Day, the group used its aircraft for humanitarian and occupation-related duties, including delivering supplies to Allied prisoner-of-war camps, conducting show-of-force flights, and surveying bomb damage over Japan. It transferred to Clark Field in the Philippines in March 1946 and was inactivated there on 30 June 1946. The lineage described in the historical record places it under the Second Air Force during its American training period, the 313th Bombardment Wing in the Pacific, and the Thirteenth Air Force during its final months.
- 1946
Inactivated at Clark Field
[1]The group ended its existence at Clark Field, Philippines, on 30 June 1946.
- 1945
First combat mission
[1]The group flew its first combat mission on 24 January against targets connected with Iwo Jima and Truk.
- 1945
First Distinguished Unit Citation
[1]The Ota, Japan, mission on 10 February earned the group its first Distinguished Unit Citation.
- 1945
Mining operations begin
[1]The group began aerial-mining missions against Japanese shipping on 27 March.
- 1945
Second Distinguished Unit Citation
[1]Mining operations in the Shimonoseki Strait and Inland Sea between 17 June and 1 July were recognized with a second Distinguished Unit Citation.
- 1944
Constituted as a very-heavy bombardment group
[1]The unit was constituted on 28 February 1944 for Boeing B-29 very-heavy bombardment operations.
- 1944
Activated at Dalhart Army Air Field
[1]Activation took place on 11 March at Dalhart, Texas, followed by training at Harvard Army Air Field, Nebraska.
- 1944
Arrived at Tinian
[1]The group reached North Field, Tinian, on 19 December and began theater preparation for combat.
Products and positioning
A United States Army Air Forces very-heavy bombardment group specializing in long-range B-29 operations in the Pacific theater.
Very-heavy bomber · 1944
Boeing B-29 Superfortress
The B-29 was the group's principal combat aircraft. From Tinian, the group used the type for long-range daylight and nighttime bombing, attacks supporting Okinawa, aerial mining, postwar relief deliveries, and reconnaissance flights.
Training aircraft · 1944
Boeing B-17 Flying Fortress
The group used B-17s during its initial training at Harvard Army Air Field while awaiting the availability of B-29 aircraft. The B-17 provided an interim platform for developing heavy-bomber crews and procedures.
Marketing campaigns
- 1945Strategic bombing campaign against Japan
Japan · Pacific theater
From January through August 1945, the group conducted B-29 missions against Japanese industrial, military, port, and urban targets. It shifted from high-altitude daylight attacks toward lower-altitude nighttime incendiary operations.
Outcome. The campaign continued until Japan's surrender and included the group's final combat mission on 14–15 August.
- 1945Operation Iceberg support
Okinawa · Kyushu
The group attacked Miyazaki and Kanoya airfields on Kyushu, which supported Japanese kamikaze operations against the Allied invasion of Okinawa.
Outcome. The attacks disrupted airfields and forced Japan to retain defensive fighters near its special-attack bases.
- 1945Japanese maritime aerial-mining campaign
Shimonoseki Strait · Inland Sea
Beginning in March, the group laid mines to impede Japanese shipping. It concentrated on the Shimonoseki Strait and Inland Sea ports from 17 June to 1 July.
Outcome. The group received a second Distinguished Unit Citation for this mining campaign.
Brand decisions
1945
Shift from high-altitude precision bombing to incendiary area attacksStrategyBackground
High-altitude B-29 missions against Japan produced disappointing visual and radar-bombing results under difficult operational conditions.
Action taken
The group joined XXI Bomber Command's move toward low-altitude nighttime incendiary raids beginning in March 1945.
Aftermath
The new approach became a central part of the group's operations through August 1945.
1945
Adoption of aerial mining as a major missionStrategyBackground
The Pacific air campaign sought ways to restrict Japanese maritime movement and access to ports and internal waterways.
Action taken
The 505th began mining operations on 27 March and concentrated on the Shimonoseki Strait and Inland Sea during June and July.
Aftermath
The group became the only XXI Bomber Command group identified as conducting these mining missions and earned a second Distinguished Unit Citation.
Sources1 sources
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