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Conduct of a World War II bombing mission with the Norden Bombsight is demonstrated in this Army Air Forces training film.
Also see: Norden Bombsight Preflight Inspection
Public domain film from the US Government, slightly cropped to remove uneven edges, with the aspect ratio corrected, and mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).
http://creativecommons.org/licenses/by-sa/3.0/
http://en.wikipedia.org/wiki/Norden_bombsight
The Norden bombsight was a tachometric bombsight used by the United States Army Air Forces (USAAF) and the United States Navy during World War II, and the United States Air Force in the Korean and the Vietnam Wars to aid the crew of bomber aircraft in dropping bombs accurately. Key to the operation of the Norden were two features; an analog computer that constantly calculated the bomb’s trajectory based on current flight conditions, and a linkage to the bomber’s autopilot that let it react quickly and accurately to changes in the wind or other effects.
Together, these features allowed for unprecedented accuracy in day bombing from high altitudes; in testing the Norden demonstrated a circular error probable (CEP) of 23 metres (75 ft), an astonishing performance for the era. This accuracy allowed direct attacks on ships, factories, and other point targets. Both the Navy and the AAF saw this as a means to achieve war aims through high-altitude bombing, without resorting to area bombing, as proposed by European forces. To achieve these aims, the Norden was granted the utmost secrecy well into the war, and was part of a then-unprecedented production effort on the same scale as the Manhattan Project. Carl L. Norden, Inc. ranked 46th among United States corporations in the value of World War II military production contracts.
In practice it was not possible to achieve this level of accuracy in combat conditions, with the average CEP in 1943 being 370 metres (1,200 ft). Both the Navy and Air Forces had to give up on the idea of pinpoint attacks during the war. The Navy turned to dive bombing and skip bombing to attack ships, while the Air Forces developed the lead bomber concept to improve accuracy. Nevertheless, the Norden’s reputation as a pin-point device lived on, due in no small part to Norden’s own advertising of the device after secrecy was reduced during the war.
The Norden saw some use in the post-World War II era, especially during the Korean War. Post-war uses were greatly reduced due to the introduction of radar-based systems, but the need for accurate daytime attacks kept it in service for some time. The last combat use of the Norden was in the US Navy’s VO-67 squadron, which used them to drop sensors onto the Ho Chi Minh Trail as late as 1967. The Norden remains one of the best known bombsights of all time…
The Norden sight was designed by Carl Norden, a Dutch engineer educated in Switzerland who emigrated to the U.S. in 1904. In 1911, Norden joined Sperry Gyroscope to work on ship gyrostabilizers, and then moved to work directly for the US Navy as a consultant. At the Navy, Norden worked on a catapult system for a proposed flying bomb that was never fully developed, but this work introduced various Navy personnel to Norden’s expertise with gyro stabilization.
During World War I it was already realized that one major source of error in bombing was levelling the aircraft enough so the bombsight pointed straight down…
As aircraft grew larger it became common for the pilot and bomb aimer to be separated so they would have difficulty seeing each other. This led to the introduction of the pilot direction indicator, or PDI…
Norden’s first attempt at an improved bombsight was actually an advance in PDI design…
The first of these Mark XI bombsights was delivered to the Navy’s proving grounds in Virginia in 1924…
While the Mk. XI was reaching its final design, Norden was already considering an improved version…
The new design, the Mark XV, was delivered in production quality in the summer of 1931. In testing it proved to eliminate all of the problems of the earlier Mk. XI design. From 1,200 metres (4,000 ft) altitude the CEP was down to only 11 metres (35 ft) for the prototype, while even the latest production Mk. XI’s were 17 metres (55 ft). At higher altitudes, a series of 80 bomb runs demonstrated a CEP of 23 metres (75 ft).[2] In a test on 7 October 1931, the Mk. XV dropped 50% of its bombs on a static target, the USS Pennsylvania, while a similar aircraft with the Mk. XI had only 20% of its bombs hit…