On the Origin of Strips

1922-2022 AIR TRAFFIC CONTROL

IFATCA

zby Philippe Domogala, Chairman IFATCA 100 Years ATC Task Force

Around 1936, the early air traffic control centres in the United States (called ‘stations’ at the time) had no standardised way of displaying a flight’s progress to the controllers. Initially, the aircraft positions were displayed by moving pieces of paper – colloquially called “shrimp boats” – on a large, horizontal map. The positions were updated every 15 minutes when new position reports were received by radio. The information on each flight was written on a big blackboard using chalk: flight number, type of aircraft, departure, destination, estimated times, etc. of each flight. It is partially visible on the background of the photo with the two controllers. As the traffic increased, both methods became cumbersome and the Bureau of Air Commerce (the predecessor of the U.S. Federal Aviation Administration [FAA] and the fist employer of the controllers) asked its controllers to use their ingenuity to help improve the equipment.

The first attempt to replace the blackboard and the "shrimp boats" was done by Lee Warren, one of the 15 original federal corps of airway controllers in the U.S., who worked in Washington, D.C. He designed a “sequencing Board,” which consisted of 20 interchangeable metal slates, one for each aircraft. When filled, this mimicked a blackboard but the slates could be swapped around, allowing the flights to be sequenced vertically. Each (relatively heavy) metal slate was fixed onto the board with a rod. To change the position, one had to press a pedal with a pulley to lift the whole thing. “Anyone who could work a full shift without getting a bruised finger or a skinned shin bone got a free drink after hours,” joked Warren.

This cumbersome device was soon abandoned when John Huber, another U.S. controller, this time from Newark, designed the first “flight progress board” in 1936. This used paper strips with small, light metal holders. This system proved popular among controllers. Despite this full standardisation of his stripboard across all U.S. centres did not happen until 1938, following the establishment of the Civil Aeronautical Authority (another forerunner of the FAA). After World War II, it would become a standard as it was introduced in nearly every ATC unit worldwide.

More than 80 years later, the same principal design remains widely in use in many parts of the world. Even in some ‘paperless’ systems, the strips are emulated on electronic displays.y

Source and credits:

“Bonfires to Beacons,” Nick Komons, published by the FAA, 1978.

To contact us, use following email for the chairman of the IFATCA 100 years task force email:philippe.domogala@ifatca.org

Photos from FAA