Maintainer Personal Limits

The ‘human factor’ has most commonly been associated with pilots and most of us would have heard of the ‘IM SAFE’ mnemonic checklist for pilot risk management. However, the ‘human factor’ and IM SAFE applies to maintainers to the same degree as pilots. An area of further focus in human factors for maintainers is the point of ‘not admitting limitations’.

Aircraft maintainers are known for their “Can Do” attitude, which motivates them to do exceptional work despite all the challenges. However, this mentality can backfire at times. “I have not been properly trained on this, but I have so much experience, I can figure out how to do the task without any training or supervision. How hard can it be? I have a Maintenance Authority / Licence after all. That proves I can do it. Sure, I can take care of those as well!” “I’m tough! I can work 10 hours every day, month after month without much sleep. I’ll sleep when I die!”

Not admitting limitations highlights that everyone has their limits. The study of human performance limitations is a vital part of human factors training. We must understand, be honest, transparent, and assertive by admitting our limitations in order to perform our tasks effectively and safely. Exceeding our limitations decreases performance, increases risk to the individual and colleagues, and may lead to aircraft and equipment damage.

The counter measures to “not admitting limitations” include:

  • Be aware of your physical, cognitive, and technical limitations
  • Listen to your body’s warning signs
  • Letting go of your ego
  • Admit lack of knowledge
  • Always follow the correct procedures
  • Seek answers and ask for help
  • Take breaks and live a healthy lifestyle

Doctors in many Western countries take the Hippocratic Oath upon entering the profession, as a symbol of their commitment to upholding a number of ethical and moral standards. In the aircraft maintenance world, maintainers live by the ‘technician’s creed’, which was originally written by Jerome Lederer in 1941. The creed appeared on the back cover of the first issues of Flight Safety Foundation’s Aviation Technicians Bulletin in 1953 and proved to be extremely popular. Maintainers around the world wrote to request copies of the creed to hang in their offices and shops. RAAus has used this creed (although slightly modified) to send to all new and renewing Level 2 maintenance authority holders to promote a positive safety culture and to empower maintainers to admit their limitations. See the creed below.

Aviation authorities around the world have produced tried and tested personal minimums checklists for maintenance personnel to further assist in identifying limitations and as a means of quality control. See below and download a checklist for your use today!

Before you begin the task - Ask yourself the following:

  1. Have I had the proper training?
  2. Have I done this before?
  3. Do I have the knowledge I need?
  4. Do I have the technical data I need?
  5. Do I have the proper tools and equipment I need?
  6. Am I mentally prepared?
  7. Am I physically prepared?
  8. Have I taken the proper safety precautions?
  9. Do I have the required resources to perform the tasks?
  10. Have I researched the Regulations, airworthiness directives and service bulletins to ensure compliance?

After the task - Ask yourself the following:

  1. Did I perform the task to the best of my abilities?
  2. Did I perform the job task without pressure, stress and distraction?
  3. Did I perform the task using appropriate data?
  4. Did I use all the methods, techniques and practices acceptable to the industry?
  5. Did I or someone else re-inspect my work before returning the aircraft to service?
  6. Is the result equal to or better than the original design?
  7. Did I accomplish and record the required “independent checks” of affected controls?
  8. Did I record proper entries for the work I performed?
  9. Did I perform operational checks after the work was complete?
  10. Am I willing to sign off for the work performed?
  11. Am I willing to fly in the aircraft once it is approved for return to service?

This information is available within our Personal Minimums Checklist for Maintenance


Go to the bottow of the Week 1 of National Safety Month home page to view the maintainer quiz to enter the draw to win our Maintenance Prize Pack for current RAAus L1, L2 and L4 Maintainers!


        CASA                                                          QBE


Down Under Pilot Shop                            henchman                      GARMIN

lockr aero                      GME