Human Error Flashcards
What factors may cause human error to take place?
Function of system design
Task,
equipment
procedures
traffic demands
Associated with controller attributes.
What individual factors can cause errors to take place?
Job satisfaction
Fatigue
Lack of skill
Lack of information
Distraction
Multi-tasking
Misunderstanding
How do we classify errors?
General – Communication
Specific – Read back
What causes controller error?
Errors can be a slip of the tongue
failure to follow procedures
poor technique or poor attitude
What are the types of controller error?
Slips, Lapses & Mistakes
What is a Slip?
Intention correct, but not carried out as planned.
Likely to be “one off errors” E.g. “Turn
right….correction…I mean left” ‘Golf echo alpha…correction…Golf Alpha Echo’
What is a Lapse?
The controller has failed to do something.
Possible causes: Distractions Lack of attention E.g. Climbing aircraft through the level of another due attention diverted by other aircraft.
What is a Mistake?
Action performed as intended but plan faulty.
Lack of Experience, or… POOR CONTROLLING!
Sub divided into:
Errors of judgement (experience)
Poor controlling techniques
E.g. ‘Oh, That will do….’
What is a Violation?
Definition: Deliberate action known to be against the rules. This differs from an
error, as the ATCO purposefully chose to disregard procedures.
Latent condition is identified as controlled? True or false?
False
Errors categorised by lack of experience are categorised as?
Mistakes
What is an active error?
Proximal cause
Active errors occur at the point of contact between a human and some aspect
of a larger system (e.g., a human - machine interface).
What are constituents comprise Reason’s Model of Latent Conditions?
Active errors
Latent errors
Windows of opportunity
Causation chain
What is an active error?
Active errors are the proximal causes of the accident: the pilot got distracted.
Without this distraction, the accident would have been prevented.
What is a Latent error?
Latent errors are the remaining contributory elements in the organisation:
senior managers decisions,
line management pressures,
unsafe climate
culture coupled with fatigue
Confusing warnings.
Without these latent errors, the accident would have been prevented.
What are Windows of Opportunity?
Windows of opportunity refer to the opportunity for those active and latent errors to contribute to an accident. Accidents happen, yet the latent errors remain unresolved, waiting for their opportunity to strike.
What is the Causation Chain?
Causation chain all related windows of opportunity at all levels align, thus leading to an accident. Therefore the cause of most accidents can be traced through these open windows.
What is the causation model?
It’s a model (Modified from Reason 1991) that depicts accident
causation (Swiss Cheese Model). If each cause passes through a hole in 6 slices of Swiss cheese - as all
holes align - an accident is extremely likely.
What are the Causation Model Triggers?
Incomplete Procedures
Regulatory Narrowness (Institutional)
Mixed Messages
Workload Pressures (Organisation)
Responsibility Shifting (Profession);
Inadequate Training (Team);
Attention Distraction (Individual);
Clumsy Technology,
Deferred Maintenance (Technical)
How do we classify errors?
Unintended Action – SLIP - Attentional Failures (Intrusion, Omission, Mistiming)
LAPSE – Memory Failures (Forgetting, Omission, Place Losing);
Intended Action – MISTAKE – Rule Based (Misapplication of good rule, Application of bad rule); Knowledge Based (Many variables, untested process)
VIOLATION Routine violations, Exceptional violations, Acts of Sabotage
