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1953 Honeywell Advertisement Magazine Cover


The control system theory that makes for precision autoflight control of today’s modern jetliners is taken for granted, but in 1953 – only 30 years after first public demonstration of an autopilot by Lawrence Sperry in Paris – elements of that technology were still considered groundbreaking.

In this ad for Honeywell’s Altitude Controller --which was also the cover the magazine -- the company trumpets its use of what is known as the “PID” (Position, Rate and Integral) feedback control system, a process that today is used broadly for motion control devices worldwide. “Unlike other controllers, the Honeywell Altitude Control gives signals for rate of displacement and integral control as well as for displacement,” the ad states.

Honeywell promises the controller can maintain an aircraft’s altitude to plus or minus 2 ft. when cruising at 65,000 ft., improving bombing accuracy, bomb trajectory, or formation flying. The PID controller used a combination of the altitude error (above or below a preset level), the rate of the altitude error and the integral of the error (sum of the error over a certain time) to precisely and smoothly hold the desired altitude.

Honeywell wasn’t the first to discover the secret sauce. According to an article in the 1993 IEEE Control Systems journal, Nicolas Minorsky in 1922 wrote a paper for the Journal of Naval Architects describing how he developed a PID controller for a ship by translating into mathematics the actions of a helmsman steering a ship.


► Aviation Week is approaching its 100th anniversary in 2016. In a series of blogs, our editors highlight editorial content from the magazine's long and rich history, including viewpoints from the industry's most iconic names and stories that have helped change the shape of the industry.

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Aviation Week & Space Technology marked its centennial in 2016. Here, we highlight editorial content from the magazine's long and rich history.

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