With the entrance of the United States into
World War II, Wendover Field took on greater importance. It was the Army Air Force's largest bombing and gunnery range. In March 1942 the Army Air Force activated Wendover Army Air Field and also assigned the research and development of guided missiles, pilotless aircraft, and remotely controlled bombs to the site. The new base was supplied and serviced by the Ogden Air Depot at
Hill Field. In April 1942, the Wendover Sub-Depot was activated and assumed technical and administrative control of the field, under the Ogden Air Depot. The Wendover Sub-Depot was tasked to requisition, store, and issue all Army Air Forces property for organizations stationed at Wendover Field for training. On 14 September 1944, the
393d Bomb Squadron arrived at Wendover from its former base at
Fairmont Army Air Base,
Nebraska, where it had been an
operational training unit (OTU) with the
504th Bombardment Group since 12 March. When its parent group deployed to the
Marianas in early November 1944, the squadron was assigned directly to the
Second Air Force until creation of the 509th Composite Group on 17 December 1944. As part of the formation of the 509th, about 800 people stationed at the field, were transferred to the new group. To make the 509th Composite Group as self-contained as possible, other units were assigned, including the 390th Air Service Group, with the 603d Air Engineering and 1027th Materiel Squadrons; the
320th Troop Carrier Squadron, known as the "Green Hornet Airlines"; the 1395th Military Police Company, and later the 1st Ordnance Squadron. A Manhattan Project unit, the 1st Technical Detachment, was attached to the group. The
216th Army Air Forces Base Unit (Special) constructed prototype atomic weapons (without nuclear material) and drop tested them. Little was known about the flight characteristics of the prototype atom bomb designs and how the fusing mechanism would work. In February 1945, a Flight Test Section was created within the 216th Army Air Forces Base Unit to carry out testing with prototype bombs in the shape of the
Little Boy and
Fat Man bombs. It was originally equipped with five
Silverplate B-29s, three flight crews and five maintenance crews. The ground support echelon of the 509th Composite Group received movement orders and moved by rail on 26 April 1945 to its port of embarkation at
Seattle, Washington. On 6 May the support elements sailed on the
SS Cape Victory for the Marianas, while group materiel was shipped on the SS
Emile Berliner. An advance party of the air echelon flew by C-54 to
North Field, Tinian, between 15 and 22 May. It was joined by the ground echelon on 29 May 1945, marking the group's official change of station. It was from Tinian that it carried out the
atomic bombings of Hiroshima and Nagasaki. The 216th Army Air Forces Base Unit moved to
Oxnard Field in September 1945, where it was transferred to the Manhattan District's 9812th Technical Services Unit on 17 December 1945. Oxnard was later designated
Sandia Base. The Special Ordnance Detachment took with it its special tools and equipment, and even some of its buildings. The test program resumed at Sandia in January 1946.
JB-2 Testing In early September 1944, a detachment of the Special Weapons Branch,
Wright Field, Ohio, arrived at Wendover with thirteen
Republic-Ford JB-2 flying bombs. The JB-2 was a United States copy of the Nazi
V-1 flying bomb, which was reverse-engineered from malfunctioning wrecks of V-1s recovered in England. The United States JB-2 was different from the German V-1 in only the smallest of dimensions. At Wendover, a launch ramp was constructed for the JB-2, engineered from plans developed from aerial photographs of ramps used by the Germans in the Low Countries. In addition to the ground launch ramp, a B-17 Flying Fortress was modified to be able to carry the jet bomb underneath a wing and air launch it. Numerous tests were conducted and an initial production order was 1,000 units was made by the Army, with subsequent planned production of 1,000 per month. The fortunes of war in Europe in the spring of 1945 led to the decision to use the JB-2 in the Pacific Theater, to be used as part of
Operation Downfall, the planned invasion of Japan. The sudden end of the war in September 1945 led to the curtailment of the JB-2 program and the weapon was never used in combat. ==Postwar use==