Learning From Our Maintenance Mishaps

Recently within maintenance safety we’ve seen investigations that fall into the area of human factors or behavior-based failures. In safety, we categorize and group these behavior-based failures for the purpose of mishap prevention. This article will explore three examples and three different human factors: the normalization of deviance, the halo effect, and groupthink. It will also discuss ways to avoid these pitfalls that you may encounter in your maintenance career.

During a recent mishap, critical verbiage from the original discrepancy was omitted when transferring information into G081. A common practice during maintenance debrief is to summarize the pilot-reported discrepancy from the maintenance logbook to G081 (the maintenance data collection system). This intentional non-compliance with standard procedures resulted in an inaccurate representation of the discrepancy to the production staff and maintenance leadership. Then, due to complacency, the production staff failed to read the original pilot-reported discrepancy and did not properly update the status of the aircraft or elevate the seriousness of the discrepancy. This “intentional non-compliance” is called the normalization of deviance.

Dr. Diane Vaughan, a sociologist from Columbia University, coined the phrase normalization of deviance when writing about human factor failures in both the Challenger and Columbia Space Shuttle accidents:

“Normalization of deviance means that people within the organization become so much accustomed to a deviation that they don’t consider it as deviant, despite the fact that they far exceed their own rules for elementary safety.” D. Vaughan, 2010.

Dr. Terrence Kelly of Saint Louis University further explains, “What begins as deviations from standard operating rules become, with enough repetitions, normalized behavioral patterns. When this occurs, personnel no longer regard these acts as deviant, but rather as routine, rational, and entirely acceptable.” T. Kelly, 2018.

Many of you have witnessed or been aware of deviations from policy or technical guidance. Maintenance personnel are empowered to make airworthiness judgments and decisions, and they often rationalize shortcuts in the name of production, especially when under time constraints and when similar past deviant behaviors did not result in failure. This lack of failure reinforces the bad behavior.

During another investigation, it was discovered that two weeks before the fatal mishap, a maintenance team was troubleshooting a pilot-reported discrepancy on the same aircraft. At that time the TSgt in charge told the SSgt performing the engine run that he would sign off the discrepancy as is. The SSgt then responded with, “Yes sir, as you say, sergeant.” The SSgt performing the engine run may have perceived the more experienced TSgt in a positive way, and therefore she did not question his authority. This is an example of the halo effect.

Merriam-Webster defines the halo effect as “generalization from the perception of one outstanding personality trait to an overly favorable evaluation of the whole personality.” In the context of a mishap investigation, it is when a novice (or typical worker) has an unconscious prejudice of a more experienced or senior person, and because of that experience or rank, the worker makes a conscious decision to not question the senior’s action.

Another classic example of multiple human factor failures in maintenance is when a maintenance crew continued troubleshooting a flight control reset malfunction. The access panel below the wing was stuck, and the senior member of the crew suggested an unauthorized “method” to raise the spoiler. He suggested using the spoiler switch in the flight deck to hold up the spoiler and depressurize a hydraulic system while another mechanic “takes a look” at the actuator under the open spoiler. The unauthorized method was quickly agreed to by the crew. While the mechanic was under the spoiler, he disconnected a connector on the actuator. This signaled a dual loss of electrical power to the actuator. This dual loss condition prompted the actuator to act as designed, and closed the spoiler, fatally injuring the mechanic. This decision of the crew to continue to perform the unauthorized method could be an example of groupthink.

Groupthink is defined as “… a cultural phenomenon in which people strive for consensus within a group. It refers to a tendency for groups to reach a quick decision without taking the time for substantial feedback.” I.L. Janis, 1972

“Cultures are vulnerable to groupthink when group cohesion is high, decisions are deferred to the group, and the group works in relative isolation (minimal oversight and supervision). Sometimes the supervisor or manager of a group discourages disagreement and advocates unanimity to make an efficient decision and move a process along. This way individuals may be unlikely to challenge colleagues for fear of losing status. The result is a deterioration of thoughtful decision-making improvement considerations.” S. Geller, 2019

What are some mitigation strategies to prevent these pitfalls?

“When leaders admit vulnerability, own up to their mistakes, and solicit corrective feedback, they set the stage for continuous improvement and naturally stifle groupthink.” S. Geller, 2019.

In your career, you’ve seen supervisors and managers who embrace diverse opinions, invite inputs, and challenge individuals to “think outside the box,” all of which will decrease the probability of all three phenomena.

“Create a culture of understanding that some deviations are likely to occur, but they require swift attention, [and that] such deviations are intolerable. Equip employees on how to address deviance in real time.” T. Kelly, 2018.

Imagine a work culture where everyone involved in a mishap or close call was invited to solicit corrective feedback without fear of reprisal or reprimand. As part of the Just Culture, AMC has implemented and championed the Airmen Safety Action Program (ASAP). ASAPs are anonymous and are responded to by SMEs at HQ AMC. Maintenance personnel can also use an AFTO Form 22 to change technical guidance, and they may also use an AF Form 847 to submit changes to Air Force Instructions.

Hopefully this article has helped make you a little more aware of the signs of normalization of deviance, halo effect, and groupthink as well as armed you with some methods of mitigation. AMC Safety stands ready to answer any questions you may have about these Human Factors pitfalls. Email: [email protected]. We are always here to help.