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Robert L. Helmreich, Ph.D. FRAes The University of Texas

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Presentation on theme: "Robert L. Helmreich, Ph.D. FRAes The University of Texas"— Presentation transcript:

1 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

2 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

3 Threat, Error, and Undesired Aircraft State

4 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. 

5 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)

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

7 Communications

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

9 Undesired Aircraft States
Position wrong Speed wrong Heading wrong Configuration wrong

10 Threat and Error Management is the Conceptual Framework for LOSA

11 Some Representative Data from 4,800 flights

12 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

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

14 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

15 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

16 29% of flights had a threat that was mismanaged and led to some form of crew error

17 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

18 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

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

20 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

21 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

22 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

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

24 Other Applications of TEM

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

26 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

27 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

28 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

29 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


31 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.

32 The University of Texas
Human Factors Research Project

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