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Updated tutorial for the Norden Bombsight with Cross-trail information added. Sperry bombsight out did the Norden in speed, simplicity of operation, and eventual technological significance. It was the first bombsight built with all-electronic servo systems, so it responded faster than the Norden's electromechanical controls. It was much simpler to learn to master than the Norden bombsight and in the. Norden M-9 Bombsight The Norden bombsight improved accuracy by allowing bombardiers to adjust targeting based on airspeed, altitude, drift and ordnance type. The trail arm and trail plate set the distance that the bomb will lag behind the aircraft after its dropped. Lenses on the left side of. A bombsight is a device used by military aircraft to drop bombs accurately. Bombsights, a feature of combat aircraft since World War I, were first found on purpose-designed bomber aircraft and then moved to fighter-bombers and modern tactical aircraft as those aircraft took up the brunt of the bombing role.

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Updated Aug, 2018

Donated to the Massey Air Museum by Robert R. Burns

The Norden bombsight was a bombsight used by the United States Army Air Force during World War II, the Korean War, and the Vietnam War to aid the crew of bomber aircraft in dropping bombs accurately. Its operation was a closely guarded secret of World War II.

, Newark, DE (2/28/16).
dBob Burns trained at Lowry Field, CO at the Air Corps Technical School for Norden Bomb Sight maintenance and repair before going to England during WWII, he attained a rank of Master Sergeant. The bomb sight was bought as surplus after the war for around $60.00 by a friend of Bob's who knew he had maintained them during the war.

Bombardier's position in nose of B-25 Mitchell, Norden bombsight in center, Stabilizer below left. Mid-Atlantic Air Museum: http://www.maam.org/airshow/b25_nose.htm

Massey Air Museum has on display a Norden Bombsight such as would have been used by the bombardier on a B-17 Bomber (and other U.S. high altitude bombers) during WWII.

The Norden was able to determine, from variables input by the bombardier, the point at which the aircraft's bombs should be released to hit the target. It combines two primary functions: aiming and stabilization of the airplane in flight during the bomb run through the autopilot, plus bomb release.

At Massey you will see the upper unit, called the sighthead containing a gyroscope, sighting telescope and analog computer. This unit was initially classified 'Secret' prior to the war. Gen. Hap Arnold insisted on it's removal and storage under armed guard when not installed in the airplane, which was done just prior to each mission. A unit called the 'stabilizer' (which we do not have) always remained in the airplane, it contains another directional gyro which is connected to the sighthead. The autopilot enabled a bomber to be flown on a straight, level course, giving the bombardier a steady platform on which to operate the bombsight during the bombing run.

The complete bombsight consists of both of these mechanisms, lower unit or stabilizer, and the Norden upper unit. The stabilizer keeps the line-ofsight direction fixed, or controlled. It is coupled to the airplane's autopilot so it could actually fly the aircraft during the bombing run, and to the bomb racks so the Norden could release the bombs at the right time automatically when directed by the upper unit.

The telescope sight is used by the bombardier to locate the target long in advance of the drop point. The gyroscopes hold the bombsight stable. The computer solves the various mathematical problems which confront the bombardier just prior to the bombing run. The bombardier still had to consult tables and make numerous calculations before he could do the presets, he 'dialed in' the Norden with the altitude and trail for the bomb type being used plus direction headings into the Auto-Pilot (sort of like setting up your computer the first time) for each and every bomb run.

For a bomb drop to be successful, a three dimensional space plus time problem must be solved. The bomber must be steered to that point in space and at the correct time so that a dropped bomb will hit the target. The input parameters to this problem are true airspeed, altitude above the target, wind, and the ballistic characteristics of the bomb to be dropped. The bombardier computed the point in space, in two dimensions, and the Norden bombsight steered the bomber to that point. The bombsight compensated for the effects of headwind, tailwind, and crosswind. The electromechanical computer continuously solves for the present angle to the target as the bomber flies toward the target, compares this angle to the precomputed dropping angle, and released the bomb when these two angles were equal.

MASSEY'S NORDEN BOMBSIGHT (captioned photo below)

Great Expectations from World War II Magazine, January 2009 (Link)

Bombing Accuracy from World War II Magazine, January 2009 (Link)

Norden Bombsight & Stabilizer lower left (Autopilot -Stabilized Bombing Approach Equipment)

Norden Bombsight (Mark 15, Mod. 7) - Made by Carl L. Norden, Inc.

Massey Air Museum has on display a Norden Bombsight such as would have been used by the bombardier on a B-17 Bomber (and other U.S. high altitude bombers) during WWII. It combines two functions, aiming and stabilization of the airplane in flight, it's autopilot actually flew the airplane during the bomb run.

You are looking at the upper unit, the sighthead or 'football' containing gyroscopes, sighting telescope and analog computer. A second unit called the 'stabilizer' or SBAE (which we do not have and which would remain in the airplane) contains a directional gyro which is connected to the sighthead.

In the 1930s, Air Corps planners refined the concept of high-altitude daylight precision bombing of strategic targets. Two essential components of this concept were the Norden bombsight and the self-defending heavy bomber. Prior to our entry into WWII, the exalted reputation of the Norden Bombsight was being promoted by the Air Corps because it served as a tool to justify the expansion of the U.S. Army Air Corps. The doctrine of high-altitude, daylight precision bombing promised, in addition to efficiently destroying the enemy, to save the lives of our airmen and importantly, save the lives of civilians on the ground. The Norden also offered a means to help maintain the morale of airmen flying the most dangerous missions of the war by justifying their sacrifices in the know

Norden Bombsight Manual