Thread and error management
description
Transcript of Thread and error management
Threat and Error ManagementThreat and Error Management
James KlinectThe University of Texas Human Factors Research Project
IFALPA Caribbean / South America Regional Conference
November 19th, 1999
Presentation OutlinePresentation Outline
• Define error management
• External threats: An overlooked concept in error management
• Threat and error management model
• Line Operations Safety Audit (LOSA): Data source for threat
and error
• General LOSA results
• Behavioral markers
• Summary – The value of threat and error management
What is Error Management?What is Error Management?
• Error – Deviation from organizational expectations or crew intentions
• Error management - process of correcting an error before it becomes consequential to safety
ErrorError
OutcomeError
Response
Error Management
An Overlooked ConceptAn Overlooked Concept
• Adverse Weather• Terrain• Aircraft malfunctions• Poor airport conditions• Abnormal operations• Operational pressures
• ATC event or error• Maintenance event or error• Ground event or error• Dispatch event or error• Cabin event or error
• External Threats – safety threatening events that originate outside of the cockpit
• Threats increase the operational complexity for a flight
Threat and Error Management Threat and Error Management ModelModel
Error Response
Error Outcome
Error
External Threats
External Threat Management
Threat Induced Incident or
AccidentInconsequential
Data Sources for Threat and ErrorData Sources for Threat and Error
• Accident Reports• Problems
1. 1.5 accidents per million departures (not enough data)2. Retrospective data – only reflects failed system or crew
performance
• Incident Reports• Problems
1. Reports are subjective, first person accounts2. Retrospective data
• Need objective data that highlight both effective and ineffective threat and error management
Line Operations Safety Audit Line Operations Safety Audit (LOSA)(LOSA)
• Non-jeopardy observations of flight crew performance during normal operations
• Union supported• One to three months of observation• Team of airline and U.T. project observers (10-15)• Data do not identify pilots and are confidential
• Measures:• External threats and their management• Flight crew errors and their management• CRM behavioral markers• Pilot suggestions through interviews• Latent system failures
LOSA DemographicsLOSA Demographics
• Data taken from three airlines
• 184 flight crews
• 314 flight segments
External ThreatsExternal Threats
LOSA External Threat ResultsLOSA External Threat Results
• 72% of the flights had at least one external threat
• Two external threats per flight
• Most external threats on a flight = 11
• Most Frequent Threats for an airline that primarily flew into Latin America
• Adverse weather – 34% of the flights
• ATC events or errors – 34%
• Aircraft malfunctions – 15%
External Threats by Phase of FlightExternal Threats by Phase of Flight
Phase of FlightThreats by
PhaseMost Frequent
Threats by Phase
Pre-Departure / Taxi 22%
A/C malfunctionsGround events / errorOperational pressures
Takeoff / Climb 28%
Cruise 10%
Descent / Approach / Land
39%
TerrainAdverse weatherATC events and errors
Taxi / Park 1%Summary - External threats in the pre-departure phase are much different than those in the most threatening phase (descent / approach / land)
Flight Crew ErrorFlight Crew Error
Threat and Error Management Threat and Error Management ModelModel
Error Response
Error Outcome
Error
External Threats
External Threat Management
Threat Induced Incident or
AccidentInconsequential
LOSA Error ResultsLOSA Error Results
• 64% of the flights had an error
• Two errors per flight
• Most errors on a flight = 14
• Most common flight crew errors• Automation errors – 31% of all errors
• Wrong MCP and FMC modes and settings• Failure to cross-verify
• Checklist errors – 21% of all errors• Checklist performed from memory• Nonstandard usage• Missed items
Error by Phase of FlightError by Phase of Flight
Phase of FlightThreats by
PhaseError by Phase
Pre-Departure / Taxi 22% 23%
Takeoff / Climb 28% 24%
Cruise 10% 12%
Descent / Approach / Land
39% 39%
Taxi / Park 1% 2%
Summary - The most threatening phase (descent / approach / land) also contains the most error
Expanding the Model with Error Expanding the Model with Error TypesTypes
ErrorIntentional
NoncomplianceProcedural
CommunicationProficiencyDecision
Error Outcome
External Threats
External Threat Management
Threat Induced Incident or Accident
Inconsequential
Error Response
Error TypesError Types
1. Intentional Noncompliance – violationsex) Performing a checklist from memory
2. Procedural – Followed procedures but wrong executionex) Wrong altitude setting dialed into the MCP
3. Communication – Missing information or misinterpretationex) Miscommunication with ATC
4. Proficiency – Error due to a lack of knowledgeex) Lack of knowledge with automation
5. Decision – Discretionary crew decision that unnecessarily increased risk
ex) Unnecessary navigation through adverse weather
Error FrequenciesError Frequencies
6
5
6
29
54
0 20 40 60 80 100
Decision
Proficiency
Communication
Procedural
Noncompliance
Percent Frequency
Summary – Willful violations (intentional noncompliance errors) are the most frequently observed errors
Expanding the Model with Error Expanding the Model with Error ResponsesResponses
Error
External Threat Management
Threat Induced Incident or
Accident
Error Outcome
External Threats
Inconsequential
Error Response
Trap
Exacerbate
Fail to Respond
Error ResponsesError Responses
• Trap – 36% of all error responses • Error is successfully detected and managed
• Exacerbate – 11%• Error is detected but mismanaged to produce a consequential
outcome
• Fail to Respond – 53% • Error is not detected therefore not managed
Expanding the Model with OutcomesExpanding the Model with Outcomes
Recovery Additional Error
Undesired Aircraft State
Error
External Threat Management
Error Response
Threat Induced Incident or
Accident
External Threats
Inconsequential
Error OutcomesError Outcomes
• Inconsequential – 85% of all errors
• Consequential Outcomes – 15% of all errors• Additional Error – 3%
• Undesired Aircraft States – 12%
Undesired Aircraft StatesUndesired Aircraft States
• Lateral deviation• Vertical deviation• Speed too high or low• Unstable approach• Near miss• Fuel level below minimums
• Long landing• Hard landing• Landing off centerline• Wrong taxiway or ramp• Wrong runway• Wrong airport or country
• Undesired Aircraft States – Flightcrew induced deviations from normal flight that threaten safety
Error Frequencies and Error Frequencies and ConsequencesConsequences
43
69
13
6
5
6
29
54
23
2
0 20 40 60 80 100
Decision
Proficiency
Communication
Procedural
Noncompliance
Percent Consequential Percent Frequency
Summary – Proficiency and decision errors are the most difficult to manage
Intentional Noncompliance as a Intentional Noncompliance as a NormNorm
• One LOSA observer noted the following during a IOE ride• “The check airmen ran the entire taxi checklist from memory.
Bad example to set.”
• Airlines cannot allow violations to normalize
• Why?• It cultivates complacency and a disregard of rules
• Crews that commit at least one intentional noncompliance error are two times more likely to:
• Commit non-intentional errors• Have non-intentional errors with consequential outcomes
The Final Expansion: State ResponsesThe Final Expansion: State Responses
Undesired Aircraft State
ResponseMitigate
ExacerbateFail to Respond
Error Induced Incident or Accident
Error
External Threat Management
Error Response
Threat Induced Incident or
Accident
Recovery Additional Error
Undesired Aircraft State
External Threats
Inconsequential
Undesired Aircraft State Undesired Aircraft State ManagementManagement
• When an aircraft enters an undesired aircraft state, flightcrews manage the state not the error
• Undesired aircraft state responses• Mitigate – 79% of all error induced aircraft state responses• Exacerbate – 2%• Fail to respond – 12%
Threat and Error Threat and Error Management Behavioral Management Behavioral
MarkersMarkers
Behavioral MarkersBehavioral Markers
• After conducting observations on 3800 flights across seven airlines......
• Fifteen behavioral markers have been determined to be the most relevant in threat and error management
• The fifteen markers can be divided into four groups 1. Team Climate2. Planning3. Execution4. Review / Modify
Team Climate MarkersTeam Climate Markers
• Leadership • Captain showed leadership and coordinated flight deck activities
• Communication Environment • Environment for open communication was established and
maintained
• Flight Attendant Briefing• If performed, did the flight attendant brief address safety
concerns and crew coordination during emergencies
Planning Behavioral MarkersPlanning Behavioral Markers
• Briefing • Required briefing was interactive and operationally thorough
• Contingency Planning • Crew members developed strategies to manage threats before
they encountered them
• Workload Assignment • Roles and responsibilities were defined for normal and non-
normal situations
• Plans Stated • Operational plans and decisions were communicated and
acknowledged by other crew members
Execution Behavioral MarkersExecution Behavioral Markers
• Monitor / Cross-Check • Crew members actively monitored and cross-checked systems and
other crew members above and beyond procedures
• Workload Management • Operational tasks were prioritized and properly managed to handle
primary flight duties
• Vigilance • Crew members remained alert of the environment, safety threats and
the progression of the flight
• Automation Management • Automation was managed to balance situational and/or workload
requirements
Review / Modify MarkersReview / Modify Markers
• Evaluation of Plans • Existing plans were regularly reviewed and discussed
• Inquiry • Crew members asked questions to investigate and/or clarify
current plans
• Assertiveness • Crew members stated critical information and/or solutions with
the appropriate persistence
• Adaptability • Existing plans were altered under contingency situations in a
timely manner
One Last Look At The ModelOne Last Look At The Model
Undesired Aircraft State
Response
Error Induced Incident or Accident
Error
External Threat Management
Error Response
Threat Induced Incident or
Accident
Recovery Additional Error
Undesired Aircraft State
External Threats
Inconsequential
The Value of Threat and Error The Value of Threat and Error ManagementManagement
• Reinforces the goals of CRM training1. Manage external threats to safety2. Avoid flight crew error3. Manage flight crew error
• Encourages the examination of system defenses that help flight crews manage threat and error
• Aircraft design, technology, and manufacturing
• Regulations and procedures
• Training (Proficiency and CRM)
• Line support - ATC, Maintenance, Ground Handling, Dispatch and Cabin
Our WebsiteOur Website
www.psy.utexas.edu/psy/helmreich/nasaut.htm