The Dirty Dozen of Human Factors in Aviation Maintenance
In the late 1980s and early 1990s, a rise in aviation maintenance errors led to serious accidents and incidents. To address this, Gordon Dupont of Transport Canada developed the Dirty Dozen aviation model in 1993. This framework identifies twelve key aviation human factors that degrade performance and contribute to safety risks.
This article expands on our previous post about the PEAR model and supports SMS aviation training by offering practical strategies to mitigate human error in aircraft technician training and operations.
The Dirty Dozen Human Factors
1. Lack of Communication
Miscommunication among technicians, pilots, and departments can lead to critical aviation maintenance errors.
- Use logbooks and worksheets.
- Discuss task status during handovers.
- Never assume completion—verify it.
2. Lack of Teamwork
Poor collaboration affects aircraft maintenance safety and task execution.
- Clarify roles and responsibilities.
- Build trust and support.
- Promote a safety-first culture.
3. Norms
Unwritten rules may conflict with FAA human factors guidelines and standard procedures.
- Follow approved standards.
- Challenge unsafe practices.
- Report negative norms via SMS systems.
4. Lack of Assertiveness
Technicians must feel confident to speak up about safety concerns.
- Communicate risks clearly.
- Offer constructive feedback.
- Encourage open dialogue.
5. Complacency
Overconfidence from repetitive tasks can lead to skipped steps and overlooked issues.
- Treat each task as new.
- Double-check your work.
- Stay vigilant regardless of experience.
6. Fatigue
Tiredness reduces concentration and increases the risk of aviation maintenance errors.
- Recognize symptoms.
- Avoid critical tasks when exhausted.
- Take breaks when needed.
7. Stress
Workplace and personal stress can distract technicians and impair decision-making.
- Maintain a positive mindset.
- Discuss concerns with peers.
- Eat well, exercise, and take breaks.
8. Lack of Knowledge
Rapid technological changes demand continuous learning in aircraft technician training.
- Only perform tasks you’re trained for.
- Use up-to-date manuals.
- Ask for help when needed.
9. Lack of Resources
Missing tools, parts, or manpower can compromise aviation maintenance quality and safety.
- Plan ahead for parts and equipment.
- Maintain tools properly.
- Use pooling or loaning systems.
10. Lack of Awareness
Failure to recognize risks or consequences can result from routine tasks or distractions.
- Understand procedures thoroughly.
- Ask for peer reviews.
- Check for conflicts with existing repairs.
11. Distraction
Interruptions can cause skipped steps or forgotten tasks—contributing to aviation maintenance errors.
- Use detailed checklists.
- Retrace steps after interruptions.
- Secure tools and parts before leaving.
12. Pressure
Time constraints and performance demands can lead to rushed decisions and unsafe practices.
- Don’t self-impose pressure.
- Communicate concerns.
- Ask for help and prioritize safety.
Summary
Understanding the Dirty Dozen aviation human factors is essential for technicians, managers, and safety officers. By recognizing symptoms and applying mitigation strategies, aviation professionals can reduce errors and enhance aircraft maintenance safety.
This article supports the goals of SMS aviation training, aligns with FAA human factors guidelines, and is a valuable resource for anyone involved in aircraft technician training. Share it with your team to promote a safer, more informed aviation environment.