Butt Report

The Butt Report, released on 18 August 1941, was a report prepared during World War II, revealing the widespread failure of RAF Bomber Command aircraft to hit their targets. At the start of the war, Bomber Command had no real means of determining the success of its operations. Crews would return with only their word as to the amount of damage caused or even if they had bombed the target. The Air Ministry demanded that a method of verifying these claims be developed and by 1941 cameras mounted under bombers, triggered by the bomb release, were being fitted. The report was initiated by Lord Cherwell, a friend of Churchill and chief scientific advisor to the Cabinet. David Bensusan-Butt, a civil servant in the War Cabinet Secretariat and an assistant of Cherwell, was given the task of assessing 633 target photos and comparing them with crews' claims. The results, first circulated on 18 August 1941, were a shock to many, though not necessarily to those within the RAF, who knew the difficulty of night navigation and target finding. Any examination of night photographs taken during night bombing in June and July points to the following conclusions: Of those aircraft recorded as attacking their target, only one in three got within . Over the French ports, the proportion was two in three; over Germany as a whole, the proportion was one in four; over the Ruhr it was only one in ten. In the full moon, the proportion was two in five; in the new moon it was only one in fifteen. ... All these figures relate only to aircraft recorded as attacking the target; the proportion of the total sorties which reached within 5 miles is less than one-third. ... The conclusion seems to follow that only about one-third of aircraft claiming to reach their target actually reached it. Postwar studies confirmed Butt's assessment, showing that 49% of Bomber Command bombs dropped between May 1940 and May 1941 fell in open country. As Butt did not include those aircraft that did not bomb because of equipment failure, enemy action, weather or which failed to find the target, only about 5% of bombers setting out bombed within of the target.