Understanding the “Dirty Dozen”

In the realm of aviation maintenance, safety is paramount. One of the key tools for enhancing safety is understanding the “Dirty Dozen” – a list of twelve human factors that significantly contribute to maintenance errors. These factors, identified through extensive research and analysis, are crucial in understanding and preventing errors in aviation maintenance.

Gordon Dupont created the idea in 1993 while he was employed by Transport Canada. It was included in a basic Human Performance in Maintenance training course. As demonstrated by UK CAA CAP715, it has subsequently grown to be a fundamental component of Human Factors in Maintenance training programs across the globe. The “dirty dozen,” which was published in 1993, is a good resource for discussing human error in pilots, cabin crew, air traffic controllers, and ramp workers, while it is by no means an exhaustive list of human error accident antecedents.

In our introductory blog post, we listed dirty dozen for you with brief explanation. We are going to discuss the mitigations soon.

The Dirty Dozen Explained

  1. Lack of Communication: Communication is crucial in maintenance operations. Miscommunication or incomplete communication can lead to misinterpretation, missed steps, or incorrect procedures. Before, during, and after any task—and especially during the changeover of shifts—details must be communicated.
  2. Complacency: A sense of overconfidence or routine can lead to a dangerous underestimation of the risks involved in maintenance tasks. It’s crucial for maintenance personnel to remain vigilant and double-check their work. While excessive pressure and demand lead to overstress and poor performance, insufficient pressure and demand generates understress, boredom, complacency, and poor performance. Therefore, it’s critical to maintain an appropriate, or ideal, level of stress through various forms of stimulation when performing easy, repetitive, and habitual jobs, as well as when weary.
  3. Lack of Knowledge: The aviation industry is constantly evolving. Maintenance personnel must keep their knowledge up to date through continuous training and education. Asking for assistance or knowledge from others shouldn’t be interpreted as a sign of weakness; on the contrary, it should be welcomed. Never work from memory or make assumptions; instead, always refer to and follow publications and checklists.
  4. Distraction: Distractions can cause a loss of focus, leading to errors. It’s important for maintenance teams to minimize interruptions and maintain a high level of concentration. Certain workplace distractions are inevitable, like loud noises, requests for help or advice, and regular safety issues that need to be resolved right away. Other distractions, such messages from home, management decisions about non-urgent work (e.g., shift patterns, leave entitlement, meeting dates, administrative responsibilities, etc.), and social discussions, can be avoided or postponed until more suitable times.
  5. Lack of Teamwork: Many jobs and operations in aviation are team-based; no one individual or organization can be in charge of ensuring that all duties are completed safely. Effective teamwork ensures a collaborative approach to maintenance, where checks and balances can prevent errors. Poor teamwork can lead to a lack of support and oversight.
  6. Fatigue: Both cognitive and physical abilities are severely compromised by fatigue. Work schedules must be managed by aviation repair groups to provide proper sleep and attentiveness. Humans have the tendency to overestimate their capacity for coping with weariness and underestimate their actual level of exhaustion. As a result, it’s critical that employees recognize the telltale signs of exhaustion in both themselves and others.
  7. Lack of Resources: Adequate resources, including tools, manuals, and personnel, are essential for proper maintenance. Cutting corners due to resource constraints can lead to dangerous outcomes. There is a better possibility that we will finish a task more quickly, accurately, and successfully when the necessary resources are on hand. Planning ahead is therefore crucial for locating, storing, and acquiring supplies. Maintaining the available resources, which also includes the people within the organization, will be essential.
  8. Pressure: Working under pressure, especially time pressure, can result in rushed jobs and oversights. Organizations must manage schedules and expectations to mitigate this risk. Acquiring assertiveness skills will enable an employee to voice issues to coworkers, clients, and the company, as well as to say “No” and “Stop!” These abilities are necessary, and in order to guarantee that the work is finished to the necessary caliber, additional resources and assistance should always be sought when deadlines are tight.
  9. Lack of Assertiveness: Being assertive is a behavioral and communication style that enables us to positively and effectively express our demands, feelings, ideas, worries, and beliefs. Maintenance personnel should feel empowered to voice concerns and assert their professional opinions, especially when safety is at stake.
  10. Stress: Chronic stress can lead to decreased job performance. Providing support systems and managing workloads can help mitigate this factor. It’s critical to identify acute vs chronic stress and to recognize the early indicators of stress. You can manage work-related stress by practicing basic breathing and relaxation techniques.
  11. Lack of Awareness: Situational awareness is crucial. A lapse in awareness can result in missing crucial information or misjudging a situation. Working alone and focusing solely on one’s own tasks can result in tunnel vision, or a partial perspective and a lack of understanding of the impact one’s actions can have on other employees and the larger job. A lack of awareness can also be caused by other human causes like preoccupation, stress, weariness, and pressure.
  12. Norms: Workplace customs evolve with time, experience, and frequently the impact of a particular workplace culture. These behaviors can be risky and safe, as well as beneficial and terrible. Organizational culture heavily influences maintenance practices. Unhealthy norms, such as taking shortcuts, must be identified and corrected.

Understanding and tackling the “Dirty Dozen” is a vital step toward improving aircraft maintenance safety. Maintenance professionals and organizations can try to create a safer, more efficient maintenance environment by recognizing these human elements. The ultimate goal is to ensure that every aircraft meets the highest safety requirements, protecting the lives of those who operate and fly them.

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