What Crews Do:What Crews Do: Context and Concepts of Context and Concepts of

Threat and Error Threat and Error Management (TEM)Management (TEM)

Robert L. Helmreich, Ph.D. FRAesRobert L. Helmreich, Ph.D. FRAes

The University of TexasThe University of Texas

Human Factors Research ProjectHuman Factors Research Project

LOSA WEEKLOSA WEEK

Kuala LumpurKuala Lumpur

September 13, 2005September 13, 2005

GoalsGoals

Define threat and error management Define threat and error management concepts concepts

Demonstrate threat and error findings Demonstrate threat and error findings from Line Operations Safety Audits (LOSA)from Line Operations Safety Audits (LOSA)

Clarify relationship between CRM and TEMClarify relationship between CRM and TEM Place threat and error management in the Place threat and error management in the

context of flight operationscontext of flight operations

Threat, Error, Threat, Error, andand

Undesired Aircraft StateUndesired Aircraft State

DefinitionsDefinitions

ThreatThreat

Event or error that occurs outside the Event or error that occurs outside the influence of the flight crew, but which influence of the flight crew, but which requires crew attention and requires crew attention and management if safety margins are to management if safety margins are to be maintained. be maintained.

Mismanaged Threat:Mismanaged Threat: A threat that is A threat that is linked to or induces flight crew error.  linked to or induces flight crew error. 

Types of ThreatsTypes of Threats Observable ThreatsObservable Threats

KnownKnown HurricaneHurricane

UnexpectedUnexpected Engine failure on take offEngine failure on take off

Latent Threats – factors residing in the system, Latent Threats – factors residing in the system, organization or individual that increase risk. organization or individual that increase risk. Latent threats are not directly observable at the ‘sharp Latent threats are not directly observable at the ‘sharp

end’ of operations. Usually uncovered by analysis of end’ of operations. Usually uncovered by analysis of aggregate data such as confidential incident reportsaggregate data such as confidential incident reports

Equipment design issuesEquipment design issues Optical illusions Optical illusions Air traffic system designAir traffic system design Training philosophy and practicesTraining philosophy and practices Organizational culture (positive or negative)Organizational culture (positive or negative)

ErrorError

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

expectationsexpectations

Error Category

AircraftHandling

Procedural Communications

Crew-linked Undesired Crew-linked Undesired Aircraft StateAircraft State

An aircraft deviation or An aircraft deviation or incorrect configuration incorrect configuration associated with a clear associated with a clear

reduction in safety marginsreduction in safety margins

Undesired Aircraft StatesUndesired Aircraft States

Position wrongPosition wrong Speed wrongSpeed wrong Heading wrongHeading wrong Configuration wrongConfiguration wrong

Threat and Error Threat and Error Management is the Management is the

Conceptual Framework for Conceptual Framework for LOSALOSA

Some Representative DataSome Representative Datafrom 4,800 flightsfrom 4,800 flights

Carving the dataCarving the data

Data can be examined in several Data can be examined in several waysways % of all % of all threatsthreats or or errorserrors of a of a

particular typeparticular type % of all % of all flights flights with a specific threat or with a specific threat or

errorerror Average number of threats or errors Average number of threats or errors

encounteredencountered

Variability of threatVariability of threat

Range of threats/flight: 0 - 19Range of threats/flight: 0 - 19

Average number of threats/flight: Average number of threats/flight: 3.73.7

Sources of ThreatSources of Threat 2/3 of threats are environmental (wx, 2/3 of threats are environmental (wx,

airport conditions, ATC, terrain)airport conditions, ATC, terrain) 43% of environmental threats occur during 43% of environmental threats occur during

descent/approach/landingdescent/approach/landing

1/3 are airline (ground, ramp, 1/3 are airline (ground, ramp, dispatch, cabin, operational pressure, dispatch, cabin, operational pressure, mx)mx)

75% of airline threats occur during pre-75% of airline threats occur during pre-departuredeparture

The Top Three ThreatsThe Top Three Threats

54% of all flights encountered one or 54% of all flights encountered one or more weather threatsmore weather threats

54% faced one or more ATC threats54% faced one or more ATC threats

32% had aircraft malfunction/MEL 32% had aircraft malfunction/MEL threats with operational implicationsthreats with operational implications

29% of flights had a threat that 29% of flights had a threat that was mismanaged and led to was mismanaged and led to

some form of crew errorsome form of crew error

Mismanaged ThreatsMismanaged Threats

Challenging clearance Challenging clearance

from ATCfrom ATC Thunderstorms with Thunderstorms with

turbulence/icingturbulence/icing Aircraft malfunction Aircraft malfunction

unexpected by crewunexpected by crew MEL item with operational MEL item with operational

implicationsimplications Operational time pressureOperational time pressure

15% of all 15% of all

mismanaged threatsmismanaged threats 9% of all mismanaged 9% of all mismanaged

threatsthreats 6% of all mismanaged 6% of all mismanaged

threatsthreats 5% of all mismanaged 5% of all mismanaged

threats threats 5% of all mismanaged 5% of all mismanaged

threatsthreats

ATC Threats by Phase of ATC Threats by Phase of FlightFlight

50% of ATC threats during 50% of ATC threats during descent/approach/landingdescent/approach/landing

22% pre-departure22% pre-departure 15% during takeoff15% during takeoff 9% during cruise9% during cruise

50% of mismanaged ATC threats occur 50% of mismanaged ATC threats occur during descent/approach/landingduring descent/approach/landing

Variability of ErrorVariability of Error

Range of errors per flight: 0 - 24Range of errors per flight: 0 - 24

Average number of errors per flight: Average number of errors per flight: 2.62.6

Errors & Undesired Aircraft States

75% of flights had 1 or more errors75% of flights had 1 or more errors 35% of flights had a mismanaged 35% of flights had a mismanaged

errorerror 3% of flights had additional error3% of flights had additional error

32% of flights had an undesired 32% of flights had an undesired aircraft state (UAS)aircraft state (UAS)

6% of flights had a mismanaged UAS6% of flights had a mismanaged UAS

Type of ErrorType of Error

Handling errors – 36% of all errorsHandling errors – 36% of all errors Most common – unintentional speed deviationMost common – unintentional speed deviation

Procedural errors – 52% of all errorsProcedural errors – 52% of all errors Most common – checklist from memoryMost common – checklist from memory

Communications errors – 12% of all errorsCommunications errors – 12% of all errors Most common – missed ATC callMost common – missed ATC call

Most Common ErrorsMost Common Errors

25% of all flights had manual 25% of all flights had manual handling/flight control errorshandling/flight control errors

23% had automation errors23% had automation errors 21% had checklist errors21% had checklist errors 20% had SOP cross-verification 20% had SOP cross-verification

errorserrors

When Crews Err:When Crews Err:% of Errors by Phase of Flight% of Errors by Phase of Flight

Pre-departure/taxi Pre-departure/taxi 26%26% Take-off Take-off 20%20% Cruise Cruise 6% 6% Descent/approach/landing Descent/approach/landing 42%42% Taxi in 6%

Other Applications of TEMOther Applications of TEM

Using TEMUsing TEM Conceptual framework for flight crew Conceptual framework for flight crew

trainingtraining Template for assessing threats Template for assessing threats

during line checksduring line checks Basis for accident and incident Basis for accident and incident

analysisanalysis

TEM and CRM: Bob’s ErrorTEM and CRM: Bob’s Error

In describing the evolution of CRM In describing the evolution of CRM from its roots in executive from its roots in executive management training to its current management training to its current focus on cockpit behaviors, the sixth focus on cockpit behaviors, the sixth generation was described as ‘threat generation was described as ‘threat and error management’and error management’

Some airlines substituted TEM for Some airlines substituted TEM for CRM in trainingCRM in training

Human Factors/CRM + TEMHuman Factors/CRM + TEM

CRM provides countermeasures against CRM provides countermeasures against threat and error as well as supporting threat and error as well as supporting basic aspects of effective teamwork and basic aspects of effective teamwork and leadershipleadership

TEM serves as a critical component of TEM serves as a critical component of Human Factors/CRM trainingHuman Factors/CRM training

CRM is not foreverCRM is not forever Awareness and acceptance decay and need Awareness and acceptance decay and need

refresher reinforcementrefresher reinforcement

Threat and Error Threat and Error Countermeasures:Countermeasures:

CRM 101CRM 101 PlanningPlanning

Share planShare plan Develop contingenciesDevelop contingencies

ExecutionExecution Monitor and cross-checkMonitor and cross-check Manage workloadManage workload Manage automationManage automation

ReviewReview InquireInquire Modify course of actionModify course of action

The Context of Threat and The Context of Threat and Error ManagementError Management

TEM is an essential component of flightTEM is an essential component of flight

It is influenced by system factors, the It is influenced by system factors, the culture and characteristics of an culture and characteristics of an

organization, and its pilots organization, and its pilots

Crew/Workplace

Factors

Conduct FlightM anage Threats

Avoid ErrorM anage Erro r

F light Com pletionSafety

EfficiencyLearning

Morale

Inputs

Processes Outcomes

ConclusionConclusion

Threat and Error Management is a Threat and Error Management is a useful organizing concept for useful organizing concept for classification and understanding of classification and understanding of crew performance in normal operationscrew performance in normal operations

TEM helps organizations to integrate TEM helps organizations to integrate data from different sources such as data from different sources such as maintenance, dispatch, pilot reports, maintenance, dispatch, pilot reports, etc.etc.

The University of TexasThe University of TexasHuman Factors Research ProjectHuman Factors Research Project

www.psy.utexas.edu/HumanFactors