What Crews Do: Context and Concepts of Threat and Error Management (TEM) Robert L. Helmreich, Ph.D. FRAes The University of Texas Human Factors Research Project LOSA WEEK Kuala Lumpur September 13, 2005

Goals Define threat and error management concepts Demonstrate threat and error findings from Line Operations Safety Audits (LOSA) Clarify relationship between CRM and TEM Place threat and error management in the context of flight operations

Threat, Error, and Undesired Aircraft State Definitions

Threat Event or error that occurs outside the influence of the flight crew, but which requires crew attention and management if safety margins are to be maintained. Mismanaged Threat: A threat that is linked to or induces flight crew error. 

Types of Threats Observable Threats Known Hurricane Unexpected Engine failure on take off Latent Threats – factors residing in the system, organization or individual that increase risk. Latent threats are not directly observable at the ‘sharp end’ of operations. Usually uncovered by analysis of aggregate data such as confidential incident reports Equipment design issues Optical illusions Air traffic system design Training philosophy and practices Organizational culture (positive or negative)

Error Action or inaction that leads to a deviation from crew or organizational intentions or expectations

Communications

Crew-linked Undesired Aircraft State An aircraft deviation or incorrect configuration associated with a clear reduction in safety margins

Undesired Aircraft States Position wrong Speed wrong Heading wrong Configuration wrong

Threat and Error Management is the Conceptual Framework for LOSA

Some Representative Data from 4,800 flights

Carving the data Data can be examined in several ways % of all threats or errors of a particular type % of all flights with a specific threat or error Average number of threats or errors encountered

Variability of threat Range of threats/flight: 0 - 19 Average number of threats/flight: 3.7

Sources of Threat 2/3 of threats are environmental (wx, airport conditions, ATC, terrain) 43% of environmental threats occur during descent/approach/landing 1/3 are airline (ground, ramp, dispatch, cabin, operational pressure, mx) 75% of airline threats occur during pre-departure

The Top Three Threats 54% of all flights encountered one or more weather threats 54% faced one or more ATC threats 32% had aircraft malfunction/MEL threats with operational implications

29% of flights had a threat that was mismanaged and led to some form of crew error

Mismanaged Threats Challenging clearance from ATC Thunderstorms with turbulence/icing Aircraft malfunction unexpected by crew MEL item with operational implications Operational time pressure 15% of all mismanaged threats 9% of all mismanaged threats 6% of all mismanaged threats 5% of all mismanaged threats

ATC Threats by Phase of Flight 50% of ATC threats during descent/approach/landing 22% pre-departure 15% during takeoff 9% during cruise 50% of mismanaged ATC threats occur during descent/approach/landing

Variability of Error Range of errors per flight: 0 - 24 Average number of errors per flight: 2.6

Errors & Undesired Aircraft States 75% of flights had 1 or more errors 35% of flights had a mismanaged error 3% of flights had additional error 32% of flights had an undesired aircraft state (UAS) 6% of flights had a mismanaged UAS

Type of Error Handling errors – 36% of all errors Most common – unintentional speed deviation Procedural errors – 52% of all errors Most common – checklist from memory Communications errors – 12% of all errors Most common – missed ATC call

Most Common Errors 25% of all flights had manual handling/flight control errors 23% had automation errors 21% had checklist errors 20% had SOP cross-verification errors

When Crews Err: % of Errors by Phase of Flight Pre-departure/taxi 26% Take-off 20% Cruise 6% Descent/approach/landing 42% Taxi in 6%

Other Applications of TEM

Using TEM Conceptual framework for flight crew training Template for assessing threats during line checks Basis for accident and incident analysis

TEM and CRM: Bob’s Error In describing the evolution of CRM from its roots in executive management training to its current focus on cockpit behaviors, the sixth generation was described as ‘threat and error management’ Some airlines substituted TEM for CRM in training

Human Factors/CRM + TEM CRM provides countermeasures against threat and error as well as supporting basic aspects of effective teamwork and leadership TEM serves as a critical component of Human Factors/CRM training CRM is not forever Awareness and acceptance decay and need refresher reinforcement

Threat and Error Countermeasures: CRM 101 Planning Share plan Develop contingencies Execution Monitor and cross-check Manage workload Manage automation Review Inquire Modify course of action

The Context of Threat and Error Management TEM is an essential component of flight It is influenced by system factors, the culture and characteristics of an organization, and its pilots

Conclusion Threat and Error Management is a useful organizing concept for classification and understanding of crew performance in normal operations TEM helps organizations to integrate data from different sources such as maintenance, dispatch, pilot reports, etc.

The University of Texas Human Factors Research Project www.psy.utexas.edu/HumanFactors