Editing The Dam Busters (film) (section)

==Historical accuracy==
[[Image:Dam Busters bombadier.jpg|thumb|right|275px|A bomb aimer prepares to drop his bouncing bomb using an improvised device to determine the correct distance from the dam.]]
The film is largely historically accurate, with only a small number of changes made for reasons of [[Artistic license|dramatic licence]]. Some errors derive from Paul Brickhill's book, which was written when much detail about the raid was not yet in the public domain.
* [[Barnes Wallis]] said that he never encountered any opposition from bureaucracy. In the film, when a reluctant official asks what he can possibly say to the RAF to persuade them to lend a [[Vickers Wellington]] bomber for flight testing the bomb, Wallis suggests: "Well, if you told them that I designed it, do you think that might help?" Barnes Wallis was heavily involved with the design of the Wellington, as it used his [[geodetic airframe]] construction method, though he was not actually its chief designer.
* Instead of all of Gibson's tour-expired crew at [[No. 106 Squadron RAF|106 Squadron]] volunteering to follow him to his new command, only his wireless operator, Hutchinson, went with him to 617 Squadron.
* Rather than the purpose as well as the method of the raid being Wallis's sole idea, the dams had already been identified as an important target by the [[Air Ministry]] before the war.
* Gibson did not devise the ''[[searchlight|spotlights]] [[altimeter]]'' after visiting a theatre; it was suggested by [[Benjamin Lockspeiser]] of the Ministry of Aircraft Production after Gibson requested they solve the problem. It was a proven method used by [[RAF Coastal Command]] aircraft for some time.<ref>[http://www.culture24.org.uk/history+%2526+heritage/war+%2526+conflict/world+war+two/art71384 "National Archives reveals inglorious truth behind classic World War Two movies."] ''culture24.org.uk'', 2 September 2009. Retrieved: 23 December 2009.</ref>
* The wooden "coat hanger" bomb sight intended to enable crews to release the weapon at the right distance from the target was not wholly successful; some crews used it, but others came up with their own solutions, such as pieces of string in the bomb-aimer's position and/or markings on the blister.
* Gibson's dog, Nigger, is depicted being killed on the day of the raid; Nigger actually died the day before.  The correct name of the dog is frequently changed in television reruns of the film when it is broadcast.<ref>Hastings, Max. ''Operation Chastise: The RAF's Most Brilliant Attack of World War II.'' HarperCollins, New York, 2020. {{ISBN|978-0-06-295363-6}}</ref>
* No bomber flew into a hillside near a target on the actual raid. This scene, which is not in the original version, was included in the copy released on the North American market (see above). Three bombers are brought down by enemy fire and two crashed due to hitting power lines in the valleys.<ref>{{cite web|url=https://www.pbs.org/wgbh/nova/military/bombing-hitler-dams.html|title=Bombing Hitler's Dams – NOVA |date=11 January 2012 |publisher=PBS}}</ref>
* Some of the sequences showing the testing of Upkeep—the code name for the weapon—in the film are of [[de Havilland Mosquito|Mosquito]] fighter-bombers dropping the naval version of the bouncing bomb, code-named ''Highball'', intended to be used against ships. This version of the weapon was never used operationally.
* At the time the film was made, certain aspects of Upkeep were still held classified, so the actual test footage was censored to hide any details of the test bombs (a black dot was superimposed over the bomb on each frame), and the dummy bombs carried by the Lancasters were almost spherical but with flat sides rather than the true cylindrical shape.
* The dummy bomb did not show the mechanism which created the back spin.
* Ammunition shown being loaded into a Lancaster is [[.50 BMG|.50 calibre]] for [[M2 Browning]] heavy machine guns, not that for the .303 calibre machine guns found on the Lancaster in 1943.
* The scenes of the attack on the Eder Dam show a castle resembling Schloss Waldeck on the wrong side of the lake and dam. The position and angle of the lake in relation to the castle suggest that in reality the bombing-run would have needed a downhill approach to the west of the castle.
* Wallis states that his idea came from [[Horatio Nelson, 1st Viscount Nelson|Nelson]]'s bouncing cannonballs into the sides of enemy ships. (He also states that Nelson sank one ship during the [[Battle of the Nile]] with a ''[[yorker]]'', a cricket term for a ball that bounces under the bat, making it difficult to play.) There is no evidence for this claim. In a 1942 paper, Wallis mentioned the bouncing of cannonballs in the 16th and 17th centuries, but Nelson was not mentioned.<ref name="Murray, I.R. 2009">Murray, Iain. ''Bouncing-Bomb Man: The Science of Sir Barnes Wallis''. Sparkford, UK: Haynes, 2009. {{ISBN|978-1-84425-588-7}}.</ref>
* In the film Wallis (Redgrave) tells Gibson and Young that a mechanical problem with the release gear has been solved as the engineers had the correct oil in store. This is false; there was a technical problem which was solved by Sgt Charles Sackville-Bryant, who was awarded the [[British Empire Medal|BEM]] for this.{{citation needed|date=March 2018}}