One of the most sophisticated planes, the F-22 of the United States Air Force, received complaints from pilots about hypoxia (lack of oxygen) and was involved in several accidents. One of them, in 2010, went into a stall and killed the pilot. The Air Force investigation board studied the incident and two years later, in 2012, released a report attributing the accident to pilot error for not making the correct decisions.
In 2013, the General Office of the United States Department of Defense reviewed the Air Force report and disagreed with the evaluation. For them, it was not a pilot error, as if the pilot did not make the correct decisions it was likely due to hypoxia, blaming the design of the aircraft.
Why does an analysis stop when there is human error?
In the case of a bridge collapse, we conduct a thorough analysis of the incident to identify the cause of the problem and reformulate design rules to ensure that the incident does not recur. However, in cases where human error causes financial losses, damage, or even deaths, the investigation often stops as soon as human error is found. The next step is to blame and punish with a fine or imprisonment. The investigations and resulting punishments seem correct to us: “we found the culprit.” But that does not solve the problem: the same error can occur over and over again. Why don’t we treat human errors the same way?
It is important to ask why the analysis of the root cause stops when human error is found. If a machine stops working, the investigation does not stop when a broken piece is discovered. Instead, we try to understand why the piece broke, if there was any defect in its manufacture, or if the required specifications were insufficient. Therefore, it is essential to carry out a thorough analysis to identify all failures and factors that contributed to the accident, including human errors.
The five whys.
The Japanese have followed a procedure to obtain the root of the problem, in what they call “the five whys,” used by Toyota Motor Company among others. This system is based on when we search for a cause, even if you have found one, do not stop: ask yourself why that was the cause. And then ask again. Keep asking yourself until you find the true cause.
We cannot solve problems until people admit they exist. When we blame a person, it is difficult to reorganize the design structure to eliminate these problems. After all, if it is the fault of a person, replace the person.
This article is based on the book The Design of Everyday Things. Revised and expanded edition by Don Norman, 2013. Basic Books.
