Aviation fuel
American strategic bombing raids in June and July 1944 seriously damaged 24 synthetic oil plants and 69 refineries, which halted 98 per cent of all of Germany's aviation fuel plants and dropped monthly synthetic oil production to 51,000 tons. After these attacks, recovery efforts in the following month could only bring back 65 per cent of aviation fuel production temporarily. In the first quarter of 1944, Nazi Germany produced 546,000 tons of aviation fuel, with 503,000 tons came from synthetic fuel by hydrogenation. Aviation fuel stock reserves had since dropped to 70 per cent in April 1944, to 370,000 tons in June 1944, and to 175,000 tons in November. Chronic fuel shortages, severe curtailment of flying training and further accelerated deterioration in pilot quality steadily decreased the Luftwaffes fighting capacity in the last months. By the end of the campaign, American forces claimed to have destroyed 35,783 enemy aircraft. and the RAF claimed 21,622, for a total of 57,405 German aircraft claimed destroyed. The USAAF dropped 1.46 million tons of bombs on Axis-occupied Europe while the RAF dropped 1.31 million tons, for a total of 2.77 million tons, of which 51.1 per cent was dropped on Germany. In addition to the direct damages incurred by Germany's industry and air force, the Wehrmacht was forced to use millions of men, tens of thousands of guns, and hundreds of millions of shells in a desperate attempt to halt the American-British Combined Bomber Offensive.