FAA Aviation Mechanic General (AMG)Regulations, Records and Human FactorsMedium

A technician has worked four consecutive 16-hour shifts to meet an aircraft's return-to-service deadline. On the final shift, he forgets to torque a critical fitting, resulting in a discrepancy found during a post-maintenance inspection. Which Dirty Dozen factor most directly contributed to this error?

  1. ALack of assertiveness
  2. BComplacency
  3. CFatigue
  4. DNorms
Show answer & explanation

Correct answer: C. Fatigue

Fatigue results from extended work hours or insufficient rest, impairing attention, memory, and judgment—directly explaining the missed torque step after repeated long shifts.

Why the other options are wrong

  • A. Lack of assertiveness involves failing to speak up about concerns, not tiredness.
  • B. Complacency stems from routine familiarity, not physical exhaustion.
  • D. Norms refer to unofficial habits becoming accepted practice, not overwork.

Fatigue (Dirty Dozen)

Physical or mental exhaustion reducing a technician's alertness and performance, often from long hours or inadequate rest.

  • Increases risk of missed steps and errors.
  • Mitigated by duty-time limits and adequate rest periods.
  • One of the twelve maintenance human factors identified by the FAA/industry.

Memory trick: 'Tired hands, torque forgotten.'

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