Keeping it Simple: Threat and Error Management as a Pilot

Threat and Error Management (TEM) is becoming one of the main pillars of what it means to be a competent pilot. Most of the aviation industry has now completely integrated it into both the training and testing of pilots. Understanding and fully integrating TEM into everyday practices however, can still present a challenge.

For many of us it can sometimes feel a little vague what it really means during day-to-day operations. What does effective TEM actually look like while on the job, and how can you incorporate it into your daily routine and habits, in an easy and efficient way? Let’s keep things simple and go over everything you need to know to up your game!

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What is Threat and Error Management?

As aviation and the way we engage with it as pilots has changed, we’ve started to adopt the mentality that threats and errors are simply every day events. Before this model, we used to teach and think about aviation safety as ‘just don’t make errors, and avoid all threats’. Easier said than done right?

This newer TEM philosophy accepts that threats and errors will eventually present themselves, and that it’s up to us to manage them effectively. If we succeed in managing these, it could be a superior way of managing safety, as we’re not just trying to avoid threats and errors as the main way to keep things safe. Instead, we focus on ‘what are we going to do if / when X happens?

This might sound a little strange if it’s new for you, but let’s break down what the model considers, and how acknowledging that the world we live in isn’t perfect can improve overall safety.

What Does TEM Consist of?

So what does the model actually look like? Well, TEM considers 3 main elements: Threats, Errors, and Undesirable Aircraft State (UAS).

The goal here is for all of us in aviation to accurately identify the potential threats and errors, and manage or control them effectively to avoid an Undesirable Aircraft State, which can lead to hazardous outcomes.

Doesn’t sound too complicated right? It isn’t, but it does require forming habits and training yourself to think in this way. If you make it a habit to think about upcoming threats and errors, over time you will find it easier and easier to manage them.

As an example, let’s look at an hydraulic system issue during an IFR flight:

1) The unanticipated threat is an issue with the hydraulic system.

2) The error could be that both pilots get so distracted with diagnosing the issue while not adhering to multipilot SOP, that no one is flying the aircraft anymore.

3)The UAS that follows is a descent below Minimum Safe Altitude.

4) The outcome, if not managed, could be Controlled Flight Into Terrain.

However, because we are trained to manage these threats and errors, we can actively decide to adhere to SOP, the PF flies the aircraft while the PM analyses the issue, resulting in a return to safe operation after dealing with the hydraulic issue.

It’s important to keep in mind that the UAS itself is usually not the outcome. The UAS leads to an (undesired) outcome, like IIMC for instance.

What are Threats?

EASA defines a threat as:

Yea we agree, having the word ‘errors’ in there doesn’t help with not mixing things up here. But the focus here is the bit behind it that states ‘beyond the influence of the flight crew’.

An error is something we are usually actively playing a part in. Missing a checklist item, flying the wrong speeds, having a mental model that’s different than observable reality, etc.

We can split threats up into 3 main categories:

Let’s have a look at what these are!

What are Anticipated Threats?

Anticipated threats are any threats that you as flight crew could have knowledge of before they happen. Examples? Think of:

• Any sort of weather phenomena like triggered lightning
• Changes in Weight and Balance
• NOTAMS
• Known air traffic issues
• Variable wind at the destination
• Obstacles, Terrain, Wires, etc

Most of these things are detectable before you come in contact with them (literally), so it’s up to us to make sure we brief thoroughly. Awareness is key here!

What are Unanticipated Threats?

Unanticipated threats are events or states that can happen at any moment without warning. They can happen and escalate quickly if they’re not managed. Let’s look at some common ones:

• System malfunctions in flight
• Unforecast events like weather changes or undeclared NOTAMS
• Obstacles or wires that are not present on charts
• TCAS alerts or pop-up traffic
• Airport congestion causing delays and extra hold time
• Laser attacks

It is often not possible to know of these threats beforehand. Skills, experience and CRM are usually all required to manage these threats effectively!

What are Latent Threats?

Latent threats are threats that are not obvious at any stage until it might be too late to deal with them. The source could be organisational issues, pilot knowledge, the culture you’re involved in, the state of the engineering department, or simply a malfunctioning onboard system that doesn’t generate a warning or caution.

Other examples are:

• Human factors like stress, fatigue, complacency and biases
• Lack of competency
• Using information and resources that are not up to date

A huge factor with any of the types of threats is the time it takes for the crew to become aware of the issue. The longer the delay, the harder it will be for you to take action and manage the situation.

What are Errors?

EASA Defines errors as:

Essentially, errors are things you or your operator does not want to happen due to the effects on safety. We can split up errors into two different types (Reason, 1990): Skill-based errors and Mistakes:

Skill-based errors could be either something you forgot to do (memory lapse), or something you know how to do correctly, but actioned incorrectly (slip of action). A typical slip of action is pulling the wrong lever that looked like the correct one.

Mistakes could be rule based mistakes (not adhering to SOP when you should), or knowledge based (leaving the parking break off during an elevated helipad landing).

The 3 main categories where we can screw up are:

1) Aircraft Handling (when we interact with aircraft)

Think of things like flying the wrong take-off profile, not using enough thrust or engine torque, using automation incorrectly, or failing to monitor systems properly.

2) Procedures (when we apply procedures)

For example, not adhering to multicrew principles, deviating from SOP (whether intentional or unintentional), not briefing properly, not using checklists.

3) Communication (when we communicate with others)

These are errors that influence how we understand others, such as missed calls from the pilot monitoring, cockpit gradient, non-standard phraseology, culture and personality clashes, CRM breakdowns.

The longer that any of these types of errors are undetected, the more damage they can do to the operation, just like the threats we discussed earlier! Situational Awareness is the antidote here.

What are Undesired Aircraft States?

As we’ve mentioned before, threats and errors are the root causes of an undesired aircraft state (UAS). So what is a UAS exactly?

EASA defines UAS as:

That’s a lot of words for ‘any unintended situation in flight that reduces safety’.

When you look at accident reports, you will usually see a build up of circumstances that eventually result in something bad. We used to refer the Swiss cheese model for this, remember?

Threat and error management is all about accepting that these threats and errors could happen, but active management is the safety barrier, rather than aiming for a version of reality where threats and errors don’t exist at all.

We can divide UAS in 3 main categories:

1) Aircraft Handling (vortex ring state, downwind approaches, overshooting a runway, etc)

2) Ground Navigation (wrong taxiway use, using the wrong runway, miscommunication on the ground with ATC)

3) Incorrect Aircraft Configuration (Systems setup wrongly, inappropriate use of flight controls, malfunctioning or incorrect use of engine systems, inaccurate weight and balance, etc)

All of these require active management in order to change from a developing unsafe situation, to safe an outcome.

How to Identify and Manage Threats Effectively?

So TEM lays out how things can go wrong, but it also helps us with a framework to actually manage the situation in a safe and effective way!

So where do we start?

We start with countermeasures! I.e, things we can do to either prevent situations from developing, or starting in the first place.

There’s 3 types of countermeasures we can use as pilots:

Planning Countermeasures: Thinking ahead

This means planning properly in order to manage threats.

Briefing, assigning roles, who is Pilot Flying, who is Pilot Monitoring, who is responsible for X and Y, making sure everyone is aware of their responsibilities, do you have a plan B and C?

Execution Countermeasures: Actions in the moment

These are all the ways we can intervene and prevent issues from developing during flight.

The use of the autopilot, making sure you don’t fixate on certain tasks, staying aware of your surroundings and thinking ahead, the correct use of techniques to recover from unusual attitudes, emergency checklists, prioritisation of tasks, etc.

Review Countermeasures: Evaluating actions and plans

After you’ve done something, you should always ask yourself if you’ve missed anything, and also if your crew have noted anything that might have been missed.

Cockpit gradient is a huge one here, if the other pilot is afraid to speak up, you won’t get very far in this step.

Actively inviting feedback from the other side of the cockpit is vital to keep things safe. Is there hesitation? Do differences in opinion get handled in a professional way and do all points of view get taken into account?

Everyday TEM

It’s likely that you’ll already be using a number of tools and techniques to manage threats, thanks to how many of us have been trained (both initially and recurrently), as well as TEM integration into operational procedures.

Integrating TEM into your everyday operations and habits, through all phases of flight is the goal here!

• Pre-flight briefings allow you to take focussed time to consider any possible threats, which are then reviewed and updated as part of your in-flight take-off and landing briefs.
• After completing an approach briefing or recce, always aim to actively involve the other pilot, ask if there are any threats you might have missed, or were not discussed during the planning phase that have come forward.
• Aviate, Navigate, Communicate! This trusty reminder helps us focus on avoiding aircraft handling errors when an unanticipated threat occurs. If you’re part of a multi-crew the PF communicating that they have control before delving into emergency procedures or problem solving is similar.
• TEM is an active process, it doesn’t happen with a passive attitude, actively think about errors that could happen in the near future, and think of ways you can work together to manage those areas where safety margins can reduce.

Resources

Skybary on TEM

NASA on Human Error Analaysis

EHEST TEM Issue

Developing Competency in Problem-Solving and Decision Making by Alex Pollitt

Conclusion

Threat and Error Management is a framework that helps us deal with unsafe situations in flight, but it can also be used on the ground and after flight. The goal of this article is to help you assess where you can improve, and if there are areas of TEM you find harder than others.

Do you have any comments, feedback, or valuable experiences other can learn from? Let us know!