Training and strategic bombing

The squadron was first organized in October 1943 at Alamogordo Army Air Field, New Mexico, as one of the original squadrons of the 492d Bombardment Group. Its cadre was drawn from the 859th Bombardment Squadron, a former antisubmarine unit whose mission had transferred to the Navy.^[1][2] By January 1944, most of the ground echelon of the squadron had been used to form other bomber units. 2d Bombardment Division, which controlled VIII Bomber Command's Liberator units in England, began to form a new ground echelon for the squadron from personnel of bomber units already in England,^[3] while the air echelon of the 857th continued training with Consolidated B-24 Liberators at Alamogordo.^[4] The air echelon began to depart Alamogordo on 1 April 1944, following the southern ferry route, while the few remaining members of the ground echelon departed on 11 April, sailing on the RMS Queen Elizabeth on 20 April.^[3]

On 14 April, the ground echelon that had been formed in England arrived at RAF North Pickenham^{[lower-alpha 2]} The air echelon began arriving on 18 April.^[3] The squadron flew its first combat mission on 11 May 1944, joining the strategic bombing campaign with attacks primarily on targets in central Germany. During the first week in June, the squadron was diverted from strategic targets to support Operation Overlord by attacking airfields and V-1 flying bomb and V-2 rocket launch sites. It bombed coastal defenses in Normandy on D-Day, 6 June 1944, and continued interdiction attacks until the middle of the month.^[4]

Except for support of Operation Cobra, the breakout at Saint Lo, the squadron then resumed bombardment of strategic targets in Germany.^[4] However, during its three months of strategic operations the 492d Group suffered the heaviest losses of any Eighth Air Force group. On 5 August, the decision was made to withdraw the 492d Group from combat.^[3] The group's heavy losses had begun with one of the group's earliest missions, an attack on Braunschweig, in which it lost eight Liberators to enemy interceptors.^[5] When the 492d Group returned to strategic operation, on 20 June Luftwaffe fighters, primarily Messerschmitt Bf 110s, using air to air rockets shot down fourteen of the 492d Group's B-24s.^[6] Heavy losses, this time to fighters from Jagdgeschwader 3, were again suffered on 29 June.^{[7][lower-alpha 3]}

Special operations

858th Squadron B-24D marked for Carpetbagger operations^{[lower-alpha 4]}

The 857th Squadron moved to RAF Harrington in August, where it assumed the Operation Carpetbagger missions and most of the personnel and equipment of the 850th Bombardment Squadron.^[8] With the 492d Group, the squadron flew 185 Operation Carpetbagger missions by the middle of September.^[9] With black-painted aircraft configured with engine flame dampeners and optimized for night operations, the group operated chiefly over France with B-24s and C-47s, transporting agents, supplies, and propaganda leaflets to patriots. As Allied forces moved forward through northern France and into Belgium, the need for Carpetbagger missions decreased and operations ended on 16 September 1944.^[10] The squadron's support for the French Resistance earned it the French Croix de Guerre with Palm. With the drawdown of the Carpetbagger mission, the squadron concentrated on hauling gasoline to advancing mechanized forces in France and Belgium.^[1][4][11] After December 1944, the squadron began limited night bombing operations.^[11]

In March 1945, the squadron's crews and planes were assigned to other units, while it moved on paper to RAF Bassingbourn, where it took over the fighters of the former 1st Scouting Force and came under the control of the 1st Air Division.^[11] The scouting force had been organized in July 1944 to precede bomber formations attacking Europe and provide them with information to avoid weather, and in some cases, enemy interceptors.^[12] The squadron continued this mission until the end of hostilities. The squadron left England for the United States in early August 1945. In August 1945 it began to reform at Kirtland Field, New Mexico as a Boeing B-29 Superfortress very heavy bomber squadron, however it became unnecessary when the Pacific War ended and it was inactivated on 17 October 1945.^[1][11]