the university of texas at austin threat and error management model robert helmreich capt. bruce...

The University of Texas at Austin

Threat and Error Management Model

Robert Helmreich Capt. Bruce Tesmer

University of Texas Continental Airlines

ATA CRM Conference

Comair, Cincinnati

September 21,1999


Applying TEMM to a ‘pilot error’ incident:

Landing at the wrong airport

Aerospace Crew Research Project


The Flight Scenario Houston to Corpus Christi second leg of the first day

of a trip that began in Newark Captain was PF from Newark, FO to CRP Captain was highly experienced check airman

conducting IOE CRP ATIS “..good, 6,000 broken 10 miles, wind 010,

10kts. Expect loc app to Rwy 31.” Descent started early expecting VORTAC vectors to

Rwy 31 localizer. ….. On autopilot until intercepting final approach course

After CRP Vortac, App Cont. gives vectors to, and clearance for intercepting localizer and “Cleared Approach.Rwy 31 Localizer”


The Scenario – continued Turning final, the Capt sees the airport and reports to

tower “Runway in sight.” Crew has slowed and configured early to allow time

to reach landing configuration and be stable by 500’ AGL. They are surprised runway so close.

A normal landing was completed but runway shorter than expected. Landing completed with 500’ remaining

There was no terminal, only hangers. Crew taxis off Rwy and realizes they are not at CRP

The call Tower which knows they have landed at Cabaniss

External External ThreatsThreats

Known Threats

•First day as crew•IOE being given•1st leg in 737-300 round dial, 2nd in 737-500 EFIS•1st EFIS leg for FO•FO only exposure to EFIS in Level 5 device•FO’s 1st trip to CRP•Capt had not been to CRP in 3 years & had never landed to North at CRP

Unexpected Threats

•ATIS doesn’t mention 2000’ scattered cloud layer. Doesn’t warn about location of Cabaniss Field•A/C on autopilot, has problem intercepting localizer•Scattered 2,000’ cloud layer blocks fwd vision but allows ground contact for 5 miles

ExternalError

•ATC had localizer set to Rwy 13 for previous A/C doing training


Crew Error

Latent Systemic Threats Regulatory: Cabniss Field located 6nm on Corpus localizerRegulatory: no ATIS warning about Cabaniss on weekendRegulatory: chart depiction hard to readRegulatory: Cabaniss field layout looks like CRPRegulatory: MSAW warning for Cabniss disabledRegulatory: runway alignment (31) same as CorpusNavy: allows racing events except special days (Mothers’ Day)System: information on other near approaches to Cabaniss existed, but not availableOrganizational: no mention of Cabaniss on10-7 page in manual Professional: operational and professional pressure to make landing

Proficiency

Crew lacked knowledge about Cabaniss location

Fail to Respond

Undesired StateAdditional Error

Error Types

Error Responses

Error Outcomes

Procedural

Crew briefed and were flying ILS approach, did

not check DME to confirm FAF

Fail to Respond

Undesired StateAdditional Error

Error Types

Error Responses

Error Outcomes

Decision Error

Crew high & fast when lined up for Cabaniss but

stable at 500’ chose riskier decision

Fail to Respond

Undesired StateApproach tp

wrong airport

Error Types

Error Responses

Incident

Undesired Aircraft State

Outcomes

Fail to Respond

Error Outcomes


Threat and Error Totals

ExternalThreats•Expected•Unknown

External Error

Threat Recognition and Error Avoidance Behaviors -

System -- Organizational -- Professional

Latent Systemic Threats

MitigateExacerbate

Fail to Respond

IncidentAdditional ErrorRecovery

InconsequentialUndesired Aircraft State

Intentional Noncompliance-Procedural

CommunicationProficiency

Operational Decision

Fail to Respond

Additional ErrorOutcomesOutcomes

ExternalExternalThreatsThreats

ActionAction

ErrorError

ActionsActions

ActionsActions

FinalFinalOutcomeOutcome


ExternalThreats

•Expected -6 •Unknown -3

External Error1

Threat Recognition and Error Avoidance Behaviors - 2

System -- Organizational -- Professional

10 Latent Systemic Threats

MitigateExacerbate

1 Fail to Respond

1Incident

Additional ErrorRecovery

InconsequentialUndesired Aircraft State

Intentional Noncompliance1 -Procedural

Communication1 Proficiency

1- Operational Decision

3- Fail to Respond

Additional ErrorOutcomesOutcomes

ExternalExternalThreatsThreats

ActionAction

ErrorError

ActionsActions

ActionsActions

FinalFinalOutcomeOutcome


Conclusion A short flight with a highly competent captain became

very complex because of numerous latent systemic threats

These were compounded by external threat and error and crew errors

Any of a number of actions could have broken the incident sequence


About Latent Threats Latent threats are highly variable. They can

– exist for a long time– be based on tradition ‘We’ve always done it this way.’– be associated with new technology– fail to appear as threats or seem to be based on good

decisions– be difficult to resolve because corrective actions cross too

many jurisdictions and no entity takes responsibility for corrective action

– are often known by some but not communicated to others– frequently involve ‘local knowledge’

Latent threats don’t show up in training


The Future The identification of Latent Systemic Threats is

essential to safety Application of the model points to training needs and

to latent threats that need to be modified Safety, CRM, Training and Flight Ops need to

coordinate to address threat and error management


CRM Countermeasures


CRM Countermeasures Possible

External Threat and error Mental models Mental model check Cockpit Communication error

Situation was high threat but not fully recognized


Conclusions Crew faced a variety of external threats and error Crew recognized and managed several threats Latent Systemic Threats played a critical role

– They can be addressed in CRM if identified CRM countermeasures were available for error management Mental models of ATC and Crew were understandable but led to

misinterpretation of actions– A ‘Mental Model Check’ could have served as the critical

countermeasure

the university of texas at austin threat and error management model robert helmreich capt. bruce...

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