A HUMAN ERROR APPROACH TO AVIATION - dvikan

1 A HUMAN ERROR APPROACH TO AVIATIONACCIDENT ANALYSISThis page intentionally left blank A HUMAN ERROR APPROACH toAviation Accident AnalysisThe HUMAN Factors Analysis and Classification SystemDOUGLAS A. WIEGMANNU niversity of Illinois at Urbana-ChampaignSCOTT A. SHAPPELLC ivil Aerospace Medical InstituteReprinted 2004, 2005 Printed and bound in Great Britain by MPG Books Ltd, Bodmin, CornwallContentsList of FiguresviiList of TablesA cknowledgementsxiPref acexii1 Errare Hum anum Est To Err is Human1 AVIATION Safety Trends3 Some Reasons for Concern8 HUMAN ERROR and AVIATION Accidents10 Engineering Aspects of an Investigation12 HUMAN Factors Aspects of an Investigation15 Conclusion182 HUMAN ERROR Perspectives20 The Cognitive Perspective21 The Ergonomic Perspective26 The Behavioral Perspective30 The Aeromedical Perspective32 The Psychosocial Perspective34 The Organizational Perspective37 Conclusion443 The HUMAN Factors Analysis and Classification System (HFACS)

2 45 Reason's Model of Accident Causation45 Elements of a Productive System45 Breakdown of a Productive System47 Strengths and Limitations of Reason's Model49 Defining the Holes in the Cheese50 Unsafe Acts of Operators50 Errors51 Violations55 Preconditions for Unsafe Acts56 Condition of Operators57 Personnel Factors60 Environmental Factors61vi A HUMAN ERROR A pproach to A viation A ccident A nalysisUnsafe Supervision63 Organizational influences66 Conclusion704 AVIATION Case Studies using HFACS72 Sometimes Experience does Count73 HUMAN Factors Analysis using HFACS75 Summary82A World Cup Soccer Game They would Never See83 HUMAN factors Analysis using HFACS86 Summary90 The Volcano Special91 HUMAN Factors Analysis using HFACS94 Summary97 Conclusion985 Exposing the Face of HUMAN Error99 Quantifying Proficiency within the Fleet106 Crew Resource management Training.

3 Success or Failure111 The Redheaded Stepchild of Aviation116 Conclusion1216 Beyond Gut of a Framework123 Factors Affecting Validity124 Reliability124 Comprehensiveness132 Diagnosticity138 Usability145 Conclusion1477 But What of FiguresFigure first fatal AVIATION accident2 Figure and fatal commercial air carrier accidentsworldwide 1961-993 Figure trends for general and militaryaviation4 Figure Naval AVIATION accident rate and interventionstrategies across calendar years 1950 to 20005 Figure straight carrier flight deck and improvedangled carrier flight deck6 Figure costs of accidents in the Navy/Marine Corps from fiscal year 1996 to 20008 Figure of commercial jet accidents, accident rates,and traffic growth past, present, and future9 Figure of Naval AVIATION accidents associated withhuman ERROR versus those attributable solely tomechanical or environmental factors11 Figure engineering investigation and preventionprocess13 Figure HUMAN ERROR process loop17 Figure model of information processing21 Figure model22 Figure taxonomic framework for assessing aircrew error24 Figure SHEL model27 Figure of accident causation.

4 Successful completionof the task (top); Unsuccessful completion of thetask (bottom)29 Figure 's motivation, reward, and satisfactionmodel31 Figure model of accident causation33 Figure factors affecting aircrew error35 Figure domino theory of accident causation38 Figure The four "P's" of flight deck operations41 Figure of a productive system46 Figure "Swiss cheese" model of accident causation47 Figure of unsafe acts committed by aircrews51 Figure of preconditions of unsafe acts56viiviii A HUMAN ERROR A pproach to A viation A ccident A nalysisFigure of unsafe supervision63 Figure factors influencing accidents66 Figure HUMAN Factors Analysis and ClassificationSystem (HFACS)

5 71 Figure with engine number 1 inoperable (markedwith an "X") veers left due to asymmetrical thrustfrom number 4 engine74 Figure required to classify causal factors usingHFACS76 Figure of the uncontrolled collision with terrainof a DC-8 at Kansas City International Airport83 Figure descent profile and ground track during theaccident approach85 Figure and performance as a function of time ofday88 Figure of the controlled flight into terrain of theLearjet one mile short of Dulles InternationalAirport91 Figure tour route of SAT flights92 Figure , planned, and actual flight path of SATF light 2293 Figure of the in-flight collision with MountHaleakala, Maui.

6 Hawaii98 Figure and rate of Navy/Marine CorpsClass A accidents associated with at least oneviolation as defined within HFACS101 Figure The percentage of Navy/Marine Corps Class Aaccidents associated with at least one violation asdefined within HFACS. The mean percentages ofClass A accidents for the Navy/Marine Corps, Army, and Air Force are plotted withdashed lines103 Figure The percentage of Navy/Marine Corps Class Aaccidents associated with at least one violation in theyears before and after the intervention strategy wasimplemented105 Figure of accidents associated with skill-basederrors. The linear trend is plotted as a dashed line107 Figure of military TACAIR and helicopteraccidents occurring between FY 1991 and 2000 thatwere associated with skill-based errors109 List of Figures ixFigure of accidents associated with decisionerrors.

7 The linear trend is plotted as a dashed line111 Figure of accidents associated with crewresource management failures. The linear trend isplotted as a dashed line113 Figure Percentage of scheduled air carrier accidentsassociated with crew resource management linear trends for the Navy/Marine Corpsand scheduled air carrier accidents are plotted asdashed lines114 Figure of fatal GA accidents associated witheach unsafe act118 Figure Percentage of nonfatal GA accidents associated witheach unsafe act119 Figure Percentage of fatal and nonfatal GA accidentsassociated with each unsafe act120 Figure of validity with those relevant to errortaxonomies highlighted123 Figure affecting the validity of an

8 ERROR -classification system125 Figure process of testing and improving the reliabilityof an ERROR classification system126 Figure Taxonomy of Unsafe Operations127 Figure Modifications made to the Taxonomy of outlined in dashes representcategory changes. Categories deleted are indicatedwith an "X"129 Figure Additional modifications made to the Taxonomy ofUnsafe Operations. Boxes outlined in dashesrepresent category changes. Categories deleted areindicated with an "X"131 Figure of accidents associated with perceptualerrors across military and civilian AVIATION (1990-98)143 Figure of accidents associated with skill-basederrors across military and civilian AVIATION (1990-98)144 Figure as modified by the Canadian Forces (CF-HFACS)

9 147 List of TablesTable causation within the management system40 Selected examples of unsafe acts of operators52 Selected examples of preconditions of unsafe acts58 Selected examples of unsafe supervision64 Selected examples of organizational influences69 The number of accidents annually for commercial,military, and general aviation116 Reliability of the HFACS framework using militaryaccident data128 The person or organization involved with a givencausal factor135 What was done or not done by the individual ororganization identified in Table the "what" from Table was committed136 CFIT and non-CFIT accidents associated with atleast one instance of a particular causal category140 CFIT accidents occurring in clear versus visuallyimpoverished conditions141 AcknowledgementsWe never would have been able to write this book without the support andunderstanding of our loving wives.

10 We are forever grateful for theirencouragement and understanding throughout this entire endeavor. Wegreatly appreciate the hardships that both of them have had to endure. Notonly did they have to deal with managing the home fronts and children whenwe went off on our "writing trips" to get away from all the distractions of ourdaily lives, but they also had to put up with our moodiness and despair ondays when it appeared that we would never complete this would also like to thank CAPT James Fraser, COL Roger Daugherty,CAPT John Schmidt and Rear Admiral "Skip" Dirren for championingHFACS within the Navy/Marine Corps.