Threat and Error Management (TEM) is not a term you hear much in general aviation circles, but it is widely adopted among airlines and is taking hold in corporate operators as well.
I am exposed to TEM through my employer who does Part 121 training under-pinned with the Threat and Error Management philosophy.
TEM is the brainchild of human factors researchers from the University of Texas and in a way it is not new, it is rather a modernized form of risk mitigation that accounts for the human(s) that are in the loop. With so many accidents attributed to pilot error and with modern airplane reliability it makes sense that we focus on the human part of the equation.
According to Dr. Helmreich: “The easiest way to understand Threat and Error Management is to liken it to defensive driving for motorists. The purpose of defensive driving is not to teach people how to drive a vehicle (e.g., how to shift a manual transmission) but to emphasize driving techniques that people can use to minimize safety risks (e.g., techniques to control rear-wheel skids). Similarly, TEM does not teach pilots how to technically fly an airplane; instead, it promotes a proactive philosophy and provides techniques for maximizing safety margins despite the complexity of one’s flying environment. In this sense, TEM training can be framed as defensive driving for pilots.”
Threats are anything that alone, or combined with something else, can have an adverse effect on the outcome of the flight. Threats occur outside the influence of the pilot, like weather, terrain, a complex procedure, or an aircraft malfunction. Threats require your attention and management if safety is to be maintained.
Errors are pilot actions or inactions that lead to a deviation of some kind. You are likely familiar with the myriad of pilot errors that occur.
TEM accepts that human error will occur — this is a shift from previous airline safety dogma. And you can see this in the amount of human factors engineering being used by manufacturers, operators, and training organizations that have adopted these techniques.
Undesired Aircraft State
In simple terms, the goal is to avoid an Undesired Aircraft State. Keep the airplane’s vertical and horizontal flight path under our control and safe at all times.
The Reason’s Model
Physiologist James T. Reason’s 1990 Swiss cheese model is a famous threat/error chain illustration. If the issue is allowed to get through all the barriers the outcome is usually not good. The idea is to place more barriers, and with fewer holes, in front of the problem.
How can it help me?
In an airline environment TEM involves scenario-based simulator training, Crew Resource Management, specialized line-checks, and incident reporting; none of which we have in our flying. Although it is not specifically designed for general aviation, there are certainly things we can do to apply it to our everyday flying.
So you try to do everything right and something still goes wrong — now what?
There are three basic concepts you need to adopt: anticipation, recognition, and recovery.
- Anticipation: Staying alert, knowing that you can’t possible predict everything that can go wrong. Maintaining a state of vigilance and avoiding complacency.
- Recognition: The sooner you recognize that something is not right, the faster you can act to mitigate that threat or error. Early recognition obviously aids recovery.
- Recovery: This is you intervening in what will soon become, or has already become, an undesired aircraft state.
Here’s a short list of techniques you are probably already using today.
Threat Management Techniques:
- Personal weather minimums
- Self-imposed proficiency requirements
- Proper aircraft maintenance
- Severe weather avoidance
Error Management Techniques:
- Checklist discipline
- Proper use of automation
- Managing your resources (ground or flight)
- Fatigue recognition
- Distraction mitigation
Although we didn’t dive deep into the details of Threat and Error Management, this article should provide an adequate introduction and hopefully provoke some thought about risk management in your flying.