1. Threat & Error Management
Chapter 8

2. Aim
To define the principles of T.E.M., identify the differences between Threats and Errors, and discuss methods of how these may be managed

3. Objectives State the principle of TEM
Define Threats, Errors and Undesired Aircraft States (UAS)
Discuss management of and mitigation of risks
Assign further reading

4. 1. T.E.M.
What is T.E.M?
In the past aviation accidents/incidents were considered to be the direct cause of Human Error
Pilots involved in such incidents were generally ‘guilty’. Research now concludes that humans are not infallible
Pilot error is quoted as a likely factor in over 75% of aircraft accidents/incidents

5. 1. T.E.M.
What is T.E.M? (cont.)
TEM is the development of a mindset which promotes safe attitudes and actions, in order to help identify threats & minimize the likelihood of an accident occurring
T.E.M addresses the threats (external) and errors (internal) that impact the safety of flight and how we manage them to avoid undesired aircraft states (UAS)

6. 2. Threats, errors and undesired aircraft states
What is a threat?
Threats can come in a range of forms:
External threats
Internal threats
Environmental threats
Organizational threats
Latent threats
An event, situation, or hazard outside/external to the immediate operating environment, which, has potential to cause errors or impact negatively on safety

7. 2. Threats, errors and undesired aircraft states
External/Environmental Threats
Threats originating from the operational environment
Mismanagement of these can lead to errors being committed
Eg:
Distractions by crew
Weather
Heavy Traffic
Missed approach
Diversions
System failures
Terrain
Night operations

8. 2. Threats, errors and undesired aircraft states
Internal Threats
Threats originating from within the cockpit and influenced by the pilots personal performance
Eg:
Fatigue
Lack of knowledge
Language/cultural issues
Cockpit authority gradient
Proficiency

9. 2. Threats, errors and undesired aircraft states
Organisational Threats
Threats originating from within organisational infrastructure
Eg:
Poor SOP’s
Unsafe attitudes & culture
Poor training/checking
Incomplete documentation
Poor maintenance
Poor scheduling

10. 2. Threats, errors and undesired aircraft states
Latent Threats
Similar to external threats, however are not immediately apparent until an incident has occurred
Generally the result of reactive (rather than proactive) risk management
Eg:
Systemic organizational deficiencies
Poor ergonomic design
Poor runway layout/design

11. 2. Threats, errors and undesired aircraft states
Expected or Unexpected threats
Threats can either be expected or unexpected
Expected threats:
General threats associated with the line of work (eg: weather)
Identification requires a plan to follow
Management is based upon differences in plans to best minimize errors
Unexpected threats:
Identification requires broad knowledge to predict ‘what may’ happen
Relies heavily on transferable skills
Reduced through use of procedures
Eg, Aviate > Navigate > Communicate, checklists, SOP’s

12. An action or inaction which leads to deviation in expected performance
2. Threats, errors and undesired aircraft states
What is an Error?
Errors can occur in a range of forms:
Handling errors
Procedural errors
Communication errors
Proficiency errors
Operation decision errors
An action or inaction which leads to deviation in expected performance
The result is a reduced margin of safety, which increases the chances of adverse events

13. 2. Threats, errors and undesired aircraft states
Classification of error
Errors are actions which lead to deviations in performance/safety
These can be intentional or unintentional deviations
Errors in skill based behaviour due to failures of attention
Errors in skill based behaviour due memory failures
SLIP/LAPSE: THE SUBJECT HAS THE RIGHT INTENTION & RIGHT SKILLS, BUT THE ORDER OF IT IS INCORRECT
MISTAKE: THE SUBJECT EXECUTES A PLAN BUT THE BASE KNOWLEDGE IS INCORRECT TO BEGIN WITH
Execution of a plan based on flawed knowledge/rule based behaviour
Deviations from normal operations on purpose

14. 2. Threats, errors and undesired aircraft states
Classification of error (cont.)
Examples of accidents due slips/lapses:
Eastern Airlines flight 401 – Everglades crash due pilot inattention to Altitude
Helios Air 522 – Hypoxia crash due incorrect pressurization setting
Emirates EK407 – Near miss with terrain due pilot data input error
Examples of accidents due mistakes:
Air France flight 447 – stall over the Atlantic Ocean
Colgan Air 3407 – mismanaged stall due handling errors
Examples of accidents due violations:
Tenerife Disaster – pilot purposely ignored order to hold position on runway

15. 2. Threats, errors and undesired aircraft states
Handling errors
Errors which directly involve the handling or manipulation of an aircraft
Generally the result of a lack of knowledge, and best reduced through continual practice/training
With consistent practice, handling errors reduce with experience
Eg:
Misuse of autopilot
Shutting down incorrect engine
Failing to maintain altitude
Poor landing techniques

16. 2. Threats, errors and undesired aircraft states
Procedural errors
Errors induced from incorrect usage of procedures
Applies to both experienced & inexperienced pilots
Generally the result of external threats mismanaged, but not necessarily misunderstood (I.e. the intentions were good, but execution was flawed)
Eg:
Due to time constraint, the pilot flies a left hand circuit instead of a right hand as listed in ERSA
Using the incorrect checklist from the task at hand
Wrong usage of units in calculations

17. 2. Threats, errors and undesired aircraft states
Communication errors
Errors which occur as a result of information being transferred incorrectly
Ambiguous communication can also lead to procedural errors.
Use of nonstandard phraseology
Thick accents/cultural differences
Poor radio quality
Ambiguous questions/answers
E.g. Air China 981 vs. JFK Airport ATC.

18. 2. Threats, errors and undesired aircraft states
Swiss Cheese model
1990 James Reason hypothesized accidents are not the result of a single error. Rather, accidents are caused through the break down of a system and can be traced to a number of errors – rather than a single event
This is known as the “Swiss Cheese model”
A system has a number of defence mechanisms in place (eg: reporting, safety vests, door locks, etc)
As these defence mechanisms are breached, an accident will eventually occur
ACCIDENT
Errors committed

19. Should the UAS be uncorrected an accident will occur
2. Threats, errors and undesired aircraft states
So what is an Undesired Aircraft State (UAS)?
Responses to an UAS may be:
Managed - The pilot identifies and remedy’s the threat
Exacerbated - The pilot attempts to correct the situation but indirectly worsens it (a mistake)
Response failure - The pilot fails to identify the threat and the situation follows through undetected
E.g.
Stalls, dives, flight into IMC, high nose on flare
A mismanaged threat which leads to an error, and ultimately puts the aircraft in an unsafe state.
Should the UAS be uncorrected an accident will occur

20. 2. Threats, errors and undesired aircraft states
Classification of UAS
Ground UAS:
Incorrect taxi way or aircraft positioning
Collision with object on apron
Aircraft UAS:
Aircraft control
Performance deviations
Mishandling of aircraft
Configuration UAS:
Incorrect flap settings
Incorrect approach speeds
Incorrect weight & balance calculations

21. 3. Mitigation of risks & UAS
Responses
Attention switching
Should the error/hazard be managed? The situation may worsen before it gets better
E.g. Carburettor icing
Attention needs to be moved from management of the error to proper handling of the aircraft state. Management of the error may not be actively required
I.e. Response to the threat should be in proportion to the risk!

22. 3. Mitigation of risks & UAS
Risk Management
Probability vs Impact
With an idea of the total risk, tasks can be prioritised
E.g:
Aviate
Navigate
Communicate!
Example, there is a risk I may get hit with a propeller.
consequence is high, however probability is low, why? Because I use my eyes as to manage it
There is a risk that the traffic tonight will make me late for home
consequence is minimal, yet probability is high. There is no mgt for this, yet it is acceptable risk

23. 3. Mitigation of risks & UAS
Identification of risks/threats
Organizations/Pilot response to threats may be:
Reactive
Proactive
PREDICTIVE
T.E.M. effectiveness
The best cure is prevention & anticipation!

24. 3. Mitigation of risks & UAS
Tools for management
Standard Operating Procedures (SOP’s) (Rule based behaviour)
Risk Analysis
Identify all possible threats & errors
Identify impact/severity of risk/error
Implement and enforce procedures/steps to be followed
Eg: Initial actions, trouble checks, Mix Up>Pitch Up>Power Up
Rule based behaviour is enhanced through simulation
Checklists should still be referenced regardless of proficiency

25. 3. Mitigation of risks & UAS
Tools for management (cont.)
Identification & Reasoning (knowledge based behaviour)
The pilot:
Identifies the issue
Recalls previous knowledge
Decides based on the calculated risk
Assesses decision and applies feedback
=> Limited by the quality of the pilots knowledge
D – Define the problem
E – Establish criteria & desired outcomes
C – Consider all alternatives & options
I – Identify the best alternative
D – Develop a plan to implement, what must be done?
E – Evaluate and monitor the effectiveness of the decision

26. 3. Mitigation of risks & UAS
Tools for management
Situational Awareness (SA)
“The ability to perceive all elements of ones environment, understand their significance, and interpret their status with the change of any given variable”
Understanding what is happening around you at all times and the ability to predict what may happen given certain circumstances
(Situational Awareness)
E.g’s:
CLEAROFFS checks
Pre-flight & fuel planning
Reporting systems & SOP’s
Sound safety culture

27. 4. Further reading Air accidents:
Tenerife Disaster – Poor communication
Everglades accident Flight 401 – Poor resource management
Helios flight 522 – Hypoxia
Alaska Air Flight 261- Maintenance issues w/ good CRM
Atlantic Southeast Flight 528 – Poor aircraft design
Air France flight 296 – Poor use of Automation
Sioux City United 232 – Excellent example of CRM
New Zealand Air Flight 901 – Erebus crash
US Air Flight 1549 – ditching, excellent CRM
Colgan Air Flight 3407 – Fatigue & poor SOP’s
Articles:
Heroic compensations – the human factor
The search for resilience
Human factors & stress

28. Questions?