Aviation Safety Concepts and Threat and Error Management
Domain 7 tests safety models, just culture and Threat and Error Management (TEM). Expect questions on the accident pyramid, SMS, threat, error and undesired aircraft state (UAS).
Safety concepts
- Safety is the freedom from unacceptable risk, not zero accidents. Safety and security are different.
- The accident pyramid: many minor events and errors precede rare accidents; reporting and investigation target the base.
- SMS includes policy, risk management, assurance and promotion; just culture distinguishes error from recklessness.
TEM framework
- Threat: an external event or condition that increases risk, such as weather or a runway change.
- Error: a crew action or inaction that deviates from intention or expectation.
- UAS: a deviation such as wrong altitude, speed or position.
- Countermeasures trap threats, manage errors and recover from UAS before an outcome.
Worked example
A runway change creates a threat. The crew accepts a late clearance without confirming the new taxi route, then turns onto the wrong taxiway: this is an error. Stopping before crossing the hold line prevents a UAS. The correct TEM answer identifies threat, error, UAS and the countermeasure, not just 'pilot mistake'.
Traps
Treating TEM as error avoidance only; confusing threat with error; using just culture to mean no accountability; assuming SMS is paperwork rather than risk management.