H Factor

May 1, 2007
Make sure the tool fits the mechanic.

The science of human factors is not a new one. The first meeting of the Human Factors Society was held in the United States in 1957. Back then, human factors practitioners first concerned themselves with the elements of human performance and included at least one psychological component. But for the most part, human factors training stayed under the radar screen for 30 years until the tragic Aloha accident on April 28, 1988.

Those pictures of a convertible B-737 on TV every night for weeks propelled the science of aviation maintenance human factors into the spotlight. So much so that in the last 19 years we have witnessed the birth of many different variations of human factors programs designed to reduce human error. A few of these programs have been successful, many have not.

Please do not misunderstand me. I strongly support human factors training especially for mechanics. I believe that all human factor/safety programs can provide good results in reducing human factor accidents and improving safety in the short term.

However, their long-term success rate is dismal. Too many human factors initiatives fail to last the long term because the safety culture within the organization starts to break down due to combinations of internal and external stressors. Problems arise like key employees and managers leaving, escalating manpower costs, lower profits due to fierce competition, and additional marketplace pressures that nibble at the ankles of the company’s human factors program, until it falls over.

Short-term success

Perhaps the biggest enemy of an in-house human factors program is short-term success. After all, managers believe that they no longer have to worry about accidents any more; they have a safety team in place. Employees think the same. But as I said earlier, in the short term accidents do go down, life is good, and it doesn’t take long for complacency to dig in to the organization like an Alabama tick.

But as time goes by, these negative stressors frustrate empowered safety employees. They slowly lose management and employee support along with resources to improve safety. It’s a losing battle, so it’s no wonder that even the most committed finally give up and the company’s human factors program dies a slow, quiet death; a victim of its own success.

While the failure of a human factors program in an organization is sad, what is worse is how difficult it becomes to sell a brand new company human factors safety program to the employees. The employees see it as another safety program de jour and sing the company song, nod their heads at the appropriate times, but never buy in because they know it will be gone tomorrow. After all they reason, the last program died, so will this one. I think the PhD’s call this a self-fulfilling prophecy.

Market factors aside, I wonder how else can we keep these programs from failing in the long term. After all, the majority of accidents are caused by humans. Accidents cost the company tons of money so why not infuse a safety culture into the company’s organization? However, to infuse anything new into an organization’s chain of command is difficult because changing the culture requires more than just organizational changes. It requires the incorporation of, and commitment to, new ideas. For many this is difficult. Why? Because like the old saw says: all men are afraid of the dark and maintaining the status quo is always the choice of lazy men.

Description of a mechanic

But still the questions remain: “Why do these kinds of programs fail in the long term?” “Why is the intermix between safety and mechanics more difficult than with other groups?” Perhaps one of the most glaring discrepancies I have found doing research for this article is that I could not find a maintenance human factors program that took the time to identify a mechanic. Oh the maintenance tasks were defined, each job-function was locked down, and recordkeeping requirements spelled out.

But no where in the program did it define who we are. The designers of these programs always started with procedures to make each maintenance task error free. They should have started with identifying the human who was doing the task. Since a culture is defined by who people are, not by what they do, is it no wonder safety programs start to unravel in the long term because the glue that holds the safety program in the organization, the “H” factor, the human, was missing from the start.

Figuring out who is a mechanic is not that hard to do. Logic demands answering a series of questions like: “What are his physical and psychological profiles?” “What are his strengths; what are his weaknesses?” “What does he need, and what can he do without?” “Is the average mechanic an extrovert or an introvert?” “What are his communication skills?” “What is the average level of education?” “Is he a process or goal-oriented individual?” “How does he think?” “How does he learn?”

What are his core beliefs and values?” Ask enough questions and a profile of a mechanic will appear. From this profile, the company’s human factors program can be designed to meet the mechanic’s needs and not the other way around. By the way, this would make an excellent subject for an FAA research paper that besides answering the question who is a mechanic, it would also shed some light on why fewer people are choosing this profession.

Custom-designed tools

The point I am trying to make is that in order to ensure the success of any new program to reduce maintenance human error, the company management must first realize that all human factors programs provide only the “tools” to reduce human error in an organization. These “tools” must be custom designed for the mechanics on the hangar floor. The program has to be dynamic in concept and visual in presentation. Why visual? Because even I know all mechanics are visually based people.

We have to see the problem before we can fix it. By way of explanation the very best safety presentation I ever saw was a pair of safety goggles hung on a hangar wall over a 10-inch grinder. The left lens of the safety goggles had a chuck of 1/4-inch steel about an inch long stuck into it. The pencil-in sign above it simply said: “Use it or lose it!” Every mechanic used safety goggles when they used that grinder.

On June 22, 2006, the FAA published an excellent Advisory Circular AC 120-92 titled: Introduction to Safety Management Systems for Air Operators. The AC is designed to sell the Safety Management System (SMS) to large air carriers. To its credit the FAA is taking the next step to take SMS to smaller Part 135 and Part 145 repair stations later on this year.

hether FAA’s FAAST team succeeds or fails at the task of infusing a SMS into the culture of smaller organizations remains to be seen. I wish them the best.

In way of showing my support for the FAA’s SMS effort, I am going to try to make their initial sales pitch to Part 145 and Part 135 managers a little bit easier. Because the hardest thing about selling safety is trying to convince a manager of an organization that has not had an accident in six years, that he needs a safety management system.

So to reduce the initial resistance to the SMS, I dreamed up a series of 20 questions based on areas of concern that have caused safety problems in the past. The company manager should be the one who takes and grades the test. He makes the determination whether or not the company needs to set up a SMS by deciding if they are tiptoeing on the edge of disaster or living the good life in safety city. Let’s give it a try.


  1. Are there safety signs or posters visible throughout your facility? This is at least recognition of the need for a safety culture.
  2. Do you have a disaster plan in place? In case of an accident or heart attack, do you know the location and telephone number of the nearest hospital, police, or fire department? Do your employees know the numbers? How many know CPR?
  3. If you are a small shop (15 employees or less), do you know your employees’ spouses’ names? If not, you may have a communication problem.
  4. How much rework was done last year due to employee or management error? If more than 3 percent of your total invoices was rework, then you have a quality problem or the employees are tired from too much overtime.
  5. Did you have any human errors in the last year? How were these human factors errors addressed? Did the same ones happen more than once? Recurrent problems are a danger signal that says more than just one thing is wrong within the company.
  6. How much overtime was paid out last year? If it was more than 2,500 man-hours, you need a new employee.
  7. How many safety meetings/fire drills do you hold a year? No meetings, then your organization has an Alabama tick on the payroll.
  8. Have you ever asked an employee or another manager on how the company can prevent an accident from happening? If not, why not?
  9. How many mechanics have a black book or cheat sheet stashed in their toolbox on which frequently used torque values or part numbers are written? Is the data current? Can your employee prove it? Maintenance manuals do get revised.
  10. How many employees own their own special tools? When were they calibrated last? Is the special tool equivalent to the manufacturer’s special tool? Can you prove it?
  11. Is a mandatory tool inventory taken after each inspection or repair? If not, how do you know if any tool is missing?
  12. Are shift change procedures in place? Have you ever witnessed a shift change in the last six months?
  13. Have employees’ vision been tested within the last 18 months? Are dust masks or other forms of breathing protection available and being used?
  14. Are one or two employees’ getting the majority of the available overtime than the other employees? If so you have a training problem.
  15. Are the maintenance manuals being used at each workstation? Are there enough manuals to go around? No manuals visible, then the employees are winging it.
  16. Count the number of inoperative tools, equipment, jacks, etc. More than three, you have a problem. Of the jacks being used, how many leak?
  17. Can you read a newspaper in the darkest area of the hangar or work space?
  18. What is the average temperature of the hangar in the winter and summer? Check the OAT on the next airplane in the hangar for the temperature. For a better assessment of the temperature, the manager should spend three days a week on the hangar floor in January and August.
  19. What is the average noise level in the hangar? Are ear muffs or plugs available and being used? If the compressor is louder than your mother-in-law’s whisper, you have a noise problem.
  20. How much time is spent on training for each employee? No one is fully trained, no one is completely safe, no one is error free.

In closing, if you decide that your company needs to incorporate a company human factors/safety management system do yourself a favor. Don’t forget the “H” factor. For long-term success, make sure the SMS tool fits the mechanic’s hand and not the other way around.

About the Author

Bill O'Brien