Butt report

The Butt Report, released on 18 August 1941, was a report prepared during World War II, revealing the widespread failure of bombers to deliver their payloads to the correct target.

At the start of the war, RAF 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 correct 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 were already largely aware of the failure of crews to navigate to, identify and bomb the targets.

Any examination of night photographs taken during night bombing in June and July points to the following conclusions:

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 RAF Bomber Command's 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 that failed to find the target area, only about 5℅ of bombers setting out bombed within five miles of their target.

The truth about the failure of Bomber Command shook everyone. Senior RAF commanders argued that the Butt report's statistics were faulty and commissioned another report, which was delivered by the Directorate of Bombing Operations on 22 September 1941; extrapolating from an analysis of the bomb damage inflicted on British cities, it calculated that the RAF could destroy the forty-three German towns with a population of more than 100,000 using a force of 4,000 bombers. The Chief of the Air Staff, Sir Charles Portal, argued that with such a force RAF Bomber Command could win the war in six months. Not all were convinced, and when Churchill expressed his doubts, the Air Staff retrenched and said that even if it did not knock Germany out of the war, it would weaken them sufficiently to allow British armed forces back into Europe. With this compromise between the armed services, Bomber Command was allowed to keep its planned allocation of materiel. This did not stop those outside the Chiefs of Staff questioning the strategic bombing policy.

...
Wikipedia