Constituted as 331st Bombardment Group (Heavy) on 1 Jul 1942 and activated on 6 Jul. Assigned to Second AF. Equipped with B-17's and B-24's for duty as a replacement training unit. Inactivated on 1 Apr 1944.
Redesignated 331st Bombardment Group (Very Heavy). Activated on 12 Jul 1944. Assigned to Second AF. Trained for combat with B-29's. Moved to Guam, Apr-Jun 1945, and assigned to Twentieth AF. Bombed Japanese-held Truk late in Jun 1945. Flew first mission against the Japanese home islands on 9 Jul 1945 and afterward operated principally against the enemy's petroleum industry on Honshu. Despite the hazards of bad weather, fighter attacks, and heavy flak, the 331st bombed the coal liquefaction plant at Ube, the Mitsubishi-Hayama petroleum complex at Kawasaki, and the oil refinery and storage facilities at Shimotsu, in Jul 1945, and received a DUC for the missions. After the war the group dropped food and supplies to Allied prisoners of war in Japan. Inactivated on Guam on 15 Apr 1946.
Squadrons. 355th: 1944-1946. 356th: 1944-1946. 357th: 1944-1946. 461st: 1942-1944. 462d: 1942-1944. 463d: 1942-1944. 464th: 1942-1944.
Stations. Salt Lake City AAB, Utah, 6 Jul 1942; Casper AAFld, Wyo, 15 Sep 1942-1 Apr 1944. Dalhart AAFld, Tex, 12 Jul 1944; McCook AAFld, Neb, 14 Nov 1944-6 Apr 1945; Northwest Field, Guam, 12 May 1945-15 Apr 1946.
Commanders. Unkn, 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 Barnick, Oct 1945-15 Apr 1946.
Campaigns. American Theater; Air Offensive, Japan; Eastern Mandates; Western Pacific.
Decorations. Distinguished Unit Citation: Japan, 22-29 Jul 1945.
Insigne. Shield: Azure, three sea gulls volant or, on a chief of the last a thunderbolt gules, irradiated of the field. Motto: Imparido Pectore - With Undaunted Heart. (Approved 22 Dec 1942.)
Data from Air Force Combat Units of World War II By Maurer, Maurer, Published 1986