The Eighth Bomber Command (re-designated the 8th Air Force in February 1944) was activated as part of the United States Army Air Forces on January 28, 1942, at Hunter Field in Savannah, Georgia.
The following month, Brigadier General Ira C. Eaker took the headquarters to England to prepare for aerial bombardment missions against Nazi-occupied Europe. The 8th AF became the greatest air armada in history, and by mid-1944 it reached a total strength of more than 200,000 people.
About 350,000 people served in the 8th AF during the war, and at its peak, it could dispatch more than 2,000 four-engine bombers and 1,000 fighters on a single mission. For these reasons, the 8th AF became known as the “Mighty Eighth”. The Mighty Eighth compiled an impressive record during World War II, however, this achievement carried a high price as the 8th AF suffered one-half of the U.S. Army Air Forces’ casualties in World War II; 47,000-plus casualties with more than 26,000 deaths (more deaths than in the entire Marine Corps)
The 8th AF was comprised of three Air Divisions (1st, 2nd, 3rd) with each having four Combat Wings. Within each Combat Wing were three Bomb Groups and within each Bomb Group were three to four Bomb Squadrons.
For example, the B-17 Susan Ruth crew was in the 369th Squadron of the 306th Bomb Group based at Thurleigh, England which was part of the 40th Combat Wing under the 1st Air Division. The other squadrons of the 306th BG based at Thurleigh, England were the 367th, 368th, and 423rd.
Every bomber had markings on the tail of the plane which identified it. For example, the tail markings on the B-17 Susan Ruth were a Triangle denoting the 1st Air Division, a yellow strip denoting the 40th Combat Wing, an H within the Triangle denoting the 306th Bomb Group, and a green stripe on top denoting the 369th Squadron. In addition, each plane had its own specific number which for the B-17 Susan Ruth was 43199.
The map below indicates all the the 8th Air Force Bomb Groups stationed in England during the war. Note: the placement of the Bomb Groups on the map does not accurately indicate their actual locations in England.