480 likes | 1.01k Views
Explorations of Airline Flight Crew Error Management. The University of Texas at Austin March 4, 1999. Line Operations Safety Audit. Systematic observations of crew performance Team of observers from the airline and U.T. Non-jeopardy Union supported Measures:
E N D
Explorations of Airline Flight Crew Error Management The University of Texas at Austin March 4, 1999
Line Operations Safety Audit • Systematic observations of crew performance • Team of observers from the airline and U.T. • Non-jeopardy • Union supported • Measures: • CRM - behavioral markers and crew performance • Threat - external threats • Error - cockpit errors • SOP - compliance • Interview - Informal feedback from the crews about flight operations and training
The LOSA Error Database 1. International Major - 59 crews on 91 flights • International and domestic flights - South Pacific and Pacific Rim 2. U.S. Major - 65 crews on 102 flights • Only international flights - Central and South America 3. U.S. Regional - 60 crews on 121 flights • Experienced Captains with inexperienced First Officers (less than 4 years in aviation and less than one year in position)
Expected Events and Risks Unexpected Events and Risks External Error External Threats Crew-Based Errors Internal Threats Threat Recognition and Error Avoidance Behaviors CRM Behaviors Error Detection and Response Behaviors A Safer Flight Recovery to A Safer Flight Additional Error Outcomes Incidents / Accident
External Events External Errors System Defenses Crew Threat Recognition and Error Avoidance Behaviors Crew Error Detection and Management Behaviors Incident / Accident The Rain of Threats
External Events Adverse weather ATC command Terrain Aircraft systems malfunction Maintenance event Dispatch event Ground handling event Cabin event Airport conditions Operational pressure External Errors Maintenance error Dispatch error ATC error Ground crew error Cabin crew error Threats Threats increase the level of risk to safety
A Heavy Rain of Threat On one flight observation, 1. Late arriving aircraft 2. Inconsistent fuel slips 3. Weight restriction on departure 4. Weather and heavy traffic on takeoff 5. Lavatory smoke alarm during cruise 6. Weather and heavy traffic on arrival 7. ATC instructed a runway change in late final
Threat Results • 72% of the flights had one or more threats • From 0 to 10 external threats per flight • Average of 2 threats per flight
Threats by Phase of Flight Threats most frequently occur during preflight and approach
Most Common Threats 1. Adverse weather - 20% of all flights 2. Aircraft malfunctions - 12% 3. ATC event - 10% 4. External errors (ATC, Maintenance, Cabin, Dispatch, and Ground Crew) - 8% 5. Operational pressures - 8%
Threats Profile Airlines and Fleets - An Example from One Airline • Narrow body operations • were threatened more by weather / wind • 69% of flight segments vs 49% of wide body flights • were threatened more by terrain • 23% of flight segments vs 2% of wide body flights • were less threatened by aircraft abnormals • 18% of flight segments vs 67% of wide body flights
Threat Recognition and Error Avoidance Behaviors • Behaviors that crews used to recognize threats and avoid error 1. Active Captain leadership 2. Vigilance 3. Operational plans clearly stated and acknowledged 4. Staying ahead of the curve 5. Following SOP
External Events External Errors System Defenses Crew Threat Recognition and Error Avoidance Behaviors Flightcrew Errors Crew Error Detection and Management Behaviors Incident / Accident The Other Piece: Flightcrew Errors
Flightcrew Errors • Can be triggered by an external threat or occur in isolation • Flightcrew error definition - an action or inaction that leads to a deviation from crew or organizational intentions or expectations
Intentional Noncompliance Procedural Communication Proficiency Operational Decision Error Types
Error Types 1. Intentional Noncompliance - violations ex.) Omitted required briefings Performing checklists from memory Failure to cross-verify settings 2. Procedural - followed procedures but wrong execution ex.) Lever and switch settings Wrong altitude dialed Wrong MCP mode executed
Error Types 3. Communication - Misinterpretation or missing information during an exchange ex.) Wrong readbacks to ATC Missed ATC calls Wrong runway communicated 4. Proficiency - lack of knowledge or skill error ex.) Lack of stick and rudder proficiency Lack of knowledge with automation Lack of knowledge with procedures
Error Types 5. Operational Decision - discretionary decision not covered by procedures that unnecessarily increased risk ex.) Over-reliance on automation Unnecessary low maneuver on approach Unnecessary navigation through adverse weather
Intentional Noncompliance Procedural Communication Proficiency Operational Decision Error Types Trap Exacerbate Fail to Respond Error Responses
Error Responses • Trap - error is detected and managed before it becomes consequential (undesired state or additional error) • Exacerbate- error is detected but the crew’s action or inaction becomes consequential • Fail to Respond - lack of a response to an error (undetected or ignored) that can either end up being inconsequential or consequential
Intentional Noncompliance Procedural Communication Proficiency Operational Decision Error Types Trap Exacerbate Fail to Respond Error Responses Error Outcomes Inconsequential Undesired State Additional Error
Lateral deviation - heading Vertical deviation - altitude Speed to high or low Unstable approach Near miss Fuel level below minimums Vertical deviation on the G.S. Long landing Hard landing Landing off centerline Wrong taxiway or ramp Wrong runway Wrong airport Wrong country Undesired States Undesired aircraft states are deviations from normal flight that unnecessarily compromises safety
Crew-Based Accident Intentional Noncompliance Procedural Communication Proficiency Operational Decision Error Types Trap Exacerbate Fail to Respond Error Responses Error Outcomes Inconsequential Undesired State Additional Error Undesired State Responses Mitigate Additional Error
Flightcrew Error Results • 72% of the crews committed at least one error • 65% of the flights had one or more errors • From 0 to 14 errors per flight • Averaged 2 errors per flight • There were between and within-fleet differences
Consequential means leading to an undesired state or additional error Errors by Phase of Flight
Most Common Errors 1. Automated systems errors (MCP and FMC) - 21% of all flights • Failure to cross-verify settings • Wrong MCP or FMC settings • Other Intentional noncompliance errors 2. Checklist errors - 20% • Checklist performed from memory • Nonstandard checklist usage • Self-performed checklist • Procedural checklist errors
Most Common Errors 3. Sterile cockpit violations - 10% 4. ATC errors - 6% • Missed ATC calls • Omitted information (readbacks or call signs) • Accepting ATC instructions that unnecessarily increased risk • Procedural ATC errors 5. Briefing errors (omitted or incomplete) - 5%
Proficiency and Operational Decision errors are the most difficult to manage Error Management Results
Undesired State Results • Responses to Undesired States • 75% are mitigated • 9% lead to additional errors • 16% required no crew response
Error Detection and Management Behaviors • Behaviors that crews used to detect and manage errors 1. Active captain leadership 2. Environment set for open communications 3. Crew members asking questions and speaking up 4. Vigilance 5. Prioritization of tasks to manage workload 6. Monitor and Cross-Check 7. Check-list discipline
Types of crew errors profile fleets - example from one airline
Violations matter • 40% of accidents in global fatal accident database had violations Flight Safety Foundation: Approach and Landing Accident Reduction Task Force Report R. Khatwa & R. Helmreich November, 1998
Culture and violation Cross-cultural research shows that American pilots are least accepting of the need to comply with SOPs. Helmreich & Merritt (1998)
Violations as the Norm • One observer noted the following during the U.S. Regional audit on an IOE ride, “The Check Airman ran the entire taxi checklist by memory.” • Organizations cannot allow violations to normalize • Why? - Crews that commit at least one intentional noncompliance error are more likely to commit other types of error than those without an intentional noncompliance error
CRM Countermeasures to Error • Bryan’s latest analyses
CRM curriculum - recurrent • Basic CRM issues are general • The Devil is in the detail • Enormous organizational and fleet differences in error and threat • Recurrent training should be highly specific to organization with focus on fleet or operation issues such as international flying • Risk of standardized curriculum is to ignore local issues
Our Website www.psy.utexas.edu/psy/helmreich/nasaut.htm