The 331st Bombardment Group went through two incarnations during the Second World War, first as a replacement training unit and second as a B-29 unit with the Twentieth Air Force.
The first incarnation began on 6 July 1942 and saw the group equipped with a mix of B-17s Flying Fortresses and B-24 Liberators. It served as a replacement training unit, preparing crews to fill gaps in existing front-line groups. The group was inactivated on 1 April 1944.
It was reactivated on 12 July 1944 as the 331st Bombardment Group (Very Heavy). It was equipped with the B-29 and rejoined the Second Air Force for training.
In April-June 1945 the group moved to Guam, where it joined the Twentieth Air Force. Its first combat mission was a raid on Truk in late June 1945, and this was followed on 9 July 1945 by the first attack on the Japanese Home Island.
After this first raid the group concentrated its efforts against the Japanese petroleum industry. It was awarded a Distinguished Unit Citation for a series of raids in July 1945 in which it hit a coal liquefaction plant at Ube, the Mitsubishi-Hayama petrol complex at Kawasaki, and an oil refinery and storage at Shimotsu.
After the war the group was used to drop supplies to POWs. It was inactivated on Guam on 15 April 1946.
1942-April 1944: Boeing B-17 Flying Fortress and Consolidated B-24 Liberator
July 1944-April 1946: Boeing B-29 Superfortress
|1 July 1942||Constituted as 331st Bombardment Group (Heavy)|
|6 July 1942||Activated and assigned to Second Air Force|
|1 April 1944||Inactivated|
|Redesignated as 331st Bombardment Group (Very Heavy)|
|12 July 1944||Activated and assigned to Second Air Force|
|April-June 1945||To Guam and Twentieth Air Force|
|15 April 1946||Inactivated|
Unknown: Jul-Sep 1942
2d Lt William B Moeser: 17 Sep 1942
Lt Col Frank P Hunter Jr: 29 Sep 1942
Lt Col William Lewis Jr: 5 Mar 1943
Lt Col Marcus A Mullen: 1 Feb-1 Apr 1944
Maj Willard W Wilson: 26 Jul 1944
Lt Col Hadley V Saehlenou: 30 Jul 1944
Col Hoyt L Prindle: 19 Aug 1944
Col James N Peyton: 24 Jan 1945
Lt Col Roland J Barnick: Oct 1945-15 Apr 1946.
Salt Lake City AAB, Utah:
6 Jul 1942
Casper AAFM, Wyo: 15 Sep 1942-1 Apr 1944
Dalhart AAFM, Tex: 12 Jul 1944
McCook AAFld, Neb: 14 Nov 1944-6 Apr 1945
Northwest Field, Guam: 12 May 1915-15 Apr 1946.
355th Bombardment Squadron: 1944-46
356th Bombardment Squadron: 1944-46
357th Bombardment Squadron: 1944-46
461st Bombardment Squadron: 1942-44
462nd Bombardment Squadron: 1942-44
463rd Bombardment Squadron: 1942-44
464th Bombardment Squadron: 1942-44
1942-April 1944: Second Air Force
July 1944-Summer 1945: 315th Bombardment Wing; XXI Bomber Command; Second Air Force (training in US)
Summer 1945-1946: 315th Bombardment Wing; XXI Bomber Command; Twentieth Air Force