Norden bombsight
More info
- Creator
- Carl Lukas Norden, for the US Navy
- Released
- 1931 (in service)
- Type
- Mechanical analog bombing computer
- Programme cost
- roughly $1.5 billion
An analog fire-control computer that flew the aircraft during the bomb run, cost nearly as much as a nuclear weapons programme, and hit considerably worse than advertised.
Carl Norden, a Dutch-born engineer, developed the sight for the US Navy from the mid-1920s. At its core sits a gyro-stabilised telescope coupled to a mechanical calculator of gears and cams. The bombardier dialled in altitude, airspeed, wind and bomb type and held the crosshairs on the target; the machine solved the trajectory, computed the release point and took over the aircraft through the autopilot for the final minutes of the run.
The secrecy verged on liturgical. Bombardiers swore an oath to defend the sight with their lives, it was carried to the aircraft under armed guard and removed after landing. The marketing promised a bomb in a pickle barrel from 20,000 feet. In practice, during 1943 barely a fifth of bombs landed within 1,000 feet of the aiming point — cloud, turbulence and the crowding of combat formations were not in the model.
The programme cost about $1.5 billion, the same order of magnitude as the Manhattan Project. The irony runs both ways: Herman Lang, a Norden employee and German agent, handed the drawings to the Abwehr in 1938. The Germans built a version, compared it with their own Lotfernrohr 7, and concluded it was no better.