Threat and Error Management

What is Threat and Error Management?

Threat and error management in aviation is a proactive safety framework that recognises threats and errors as routine operational realities. The TEM model divides operational challenges into three core components:

• Threats: Events or conditions outside the crew's control, such as weather, ATC instructions, equipment malfunctions, or organisational pressures.
• Errors: Actions or inactions by crew that deviate from procedures, standards, or intentions—these may include procedural, communication, or aircraft handling errors.
• Undesired Aircraft States: Situations where the aircraft is in a condition that reduces safety margins, often as a result of unaddressed threats or errors.

Types of Threats

• Environmental Threats: Weather hazards (turbulence, icing), contaminated runways, complex airport layouts, or unexpected ATC changes.
• Organisational Threats: Fatigue from poor rostering, documentation errors, commercial pressures, or maintenance issues.
• Latent Threats: Hidden vulnerabilities such as flawed procedures, inadequate training, or poor system design, often only revealed during incidents or audits.

Types of Errors

• Procedural Errors: Deviating from checklists or SOPs, such as skipping a checklist item.
• Communication Errors: Misunderstandings between crew or with ATC, incorrect readbacks, or ambiguous phrasing.
• Aircraft Handling Errors: Misapplication of controls, incorrect configuration, or unstable approaches.

Countermeasures and Management

Pilots use several strategies to manage threats and errors:

• Briefings and Planning: Anticipating threats through thorough pre-flight and in-flight briefings.
• Situational Awareness: Continuously monitoring the environment and aircraft state.
• Cross-Verification: Crew members checking each other's actions and decisions.
• Standard Operating Procedures (SOPs): Relying on established procedures to reduce variability.
• Automation and System Design: Using aircraft systems that prevent or alert to errors (e.g., gear warning horns, FMC verification screens).
• Training and Recurrent Checks: Ongoing skill development to maintain proficiency and resilience under stress.

Key Principles

TEM is not about eliminating all errors but about building resilience so that threats and errors are detected, managed, and contained before they escalate into undesired aircraft states.