Is Paper Safer? The Role of Paper Flight Strips in Air Traffic Control

Motivation: Attempts to automate air traffic control have failed.

Problem: Initially: How can we help air traffic controllers make the transition from today’s paper flight strips to “more modern” computer-based systems?

Approach and Evaluation:

From what I understood, the initial perspective was that nobody seemed to get things right. Software engineers, cognitive ergonomics and sociologists were looking at different areas but were still not able to determine why the systems were not working properly mainly because they really needed to understand the role of the paper strips in air traffic control.

Two ethnographic studies were performed.

The First Study:

They followed workers for four months in an air traffic control, and tried to analyze and understand the role of paper strips. Holding a paper strip signifies the controller “owns” the aircraft. The final arrangement of the strips themselves is unimportant, what matters is how they get organized and who grabs them at one point (cooperative work) and allows for cross checking.

Design principles:

(1) Dominant to non-dominant spatial reference: the non-dominant hand sets the frame of reference for the actions of the dominant hand. E.g. positioning the paper vs. writing.

(2) Asymmetric scales of motion: the two hands operate asymmetrically over space and time. E.g. the non-dominant hand moves slower and less frequent.

(3) Precedence of on-dominant hand: the non-dominant hand begins the cooperative bimanual task followed by the dominant hand. E.g. the non-dominant hand positions the paper before the dominant hand can write.

Peripheral awareness is also an important factor. Controllers need to hear the printers, see each other people grabbing the strips, etc.

The Second Study:

Eight control rooms were visited and compared. There were three types: en-route (radar view), tower (window view) and approach (radar view).

Some places had strips that varied in color to indicate additional meaning, and one of the towers got rid of strips and put the information in the radar instead, however this case was very particular since it handles a lot less than other controls and it would be difficult to port to other towers. One of them replaced strips with a table that had small steps, but then again, it had a smaller traffic as well.

The implications were that although it is nice to improve productivity, the main focus should be safety.

Things I liked about the paper:

It was a very thorough ethnographic study and it allowed to fully understand the role of paper strips and think of potential alternatives for the future.

Things I did not like about the paper:

The question they were trying to ask from the title, “is paper safer?” was not really answered throughout the paper. Then again, it is difficult to test this since the system would have to be changed first.