Human Factors Case Study - Human Error vs Human Factors Singapore
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Human Factors Case Study - Human Error vs Human Factors Singapore Airlines Flight 006 Accident Taipai, Taiwan October 31, 2000 Excerpt from Human Factors for Process Safety Course David A. Moore, PE, CSP President AcuTech Consulting, Inc. 100 Bush Street, Suite 200 San Francisco, CA 94104 http://www.acutech-consulting.com/training/index.html SQ006 Incident Overview October 31, 2000 A multi-fatality incident involving Singapore Airlines Flight 006 (SQ006) at Taipai’s Chiang Kai-shek Airport provides a case study in human error caused by human factors vs individual human error alone SQ006 crashed into runway barricades and construction equipment on takeoff resulting in over 83 fatalities of the 159 onboard* * Photos and information credit: http://www.channelnewsasia.com/sq006/ www.acutech-consulting.com 2 SQ006 – Simply Pilot Error? The ill-fated SQ006 was on the wrong runway before it crashed on Tuesday night, said Taiwan's chief investigator at a news conference* The pilot had been cleared for takeoff on the designated runway (5-L), but instead departed the aircraft down the wrong runway (5-R), which was a parallel runway under repair at the time. The statement by Kay Yong, Taiwan's Aviation Safety Council managing director, implied that pilot error played a major role in the crash of the Boeing 747-400, which led to the death of 83 people. The cause - An obvious case of pilot error alone?? www.acutech-consulting.com 3 SQ006 – Review of the Work Situation What human errors occurred besides the pilot error? What human factors contributed to the likelihood of the initiating event? What human factors contributed to the event sequences that followed? Were there opportunities to stop the escalation of a pilot error to an accident? www.acutech-consulting.com 4 Definition of Human Error and Human Factors Before we answer those questions, let’s review the definition of human factors vs human error How do you define human error? How do you define human factors? www.acutech-consulting.com 5 Definiton of Human Error Human error is defined as “any human action (or lack thereof) that exceeds some limit of acceptability (I.e., an out-of-tolerance action) where the limits of human performance are defined by the system” From “A Manager’s Guide to Reducing Human Errors, Improving Human Performance in the Chemical Industry, Chemical Manufacturer’s Association, July 1990. www.acutech-consulting.com 6 Human Error Types 1. Intentional – deliberately commit or omit the prescribed actions 2. Unintentional – committed or omitted with no prior thought From “A Manager’s Guide to Reducing Human Errors, Improving Human Performance in the Chemical Industry, Chemical Manufacturer’s Association, July 1990. www.acutech-consulting.com 7 Definition of Human Factors Environmental, organizational, and job factors, and human and individual characteristics which influence behavior at work in a way which can affect health and safety.  Reducing Error and Influencing Behavior, HSG48, HSE (1999). www.acutech-consulting.com 8 Human and Organizational Factors Human and organizational factors can be related to the individuals that design, construct, operate, and maintain the system.  Bea, Holdsworth, and Smith, “Human and Organization Factors in the Safety of Offshore Platforms”, a paper presented at the 1996 International Workshop on Human Factors in Offshore Operations www.acutech-consulting.com 10 Four Components of Human Factors The actions or inactions of these individuals are influenced by four components: 1. The organizations that they work for 2. The procedures (formal, informal, software) they use to perform their activities 3. The structure and equipment involved in these activities 4. The environments in which the individual conducts activities. www.acutech-consulting.com 11 SQ006 Accident – 747-400 www.acutech-consulting.com 12 Transcript From the Black Box Recording of SQ006 (The recording begins from 18 seconds after 11.15 pm 1515GMT) 11.15.18 ATC (tower) Singapore 6 runway 05 left (5L). Wind 020 (degrees) at 28 (knots). Gust to 50. Clear for take off. 11.15.26 Captain - Clear for take off. Runway 05 left. Singapore 6. 11.16.19 Captain - We can see the runway not so bad. OK., I am going to put it to high first. 11.16.51 First Officer - 80 knots. 11.16.52 Captain - OK, my control. 11.17.08 First Officer - V1*. 11.17.12 Captain - (Expletive). Something there. 11.17.13 Banging sound. 11.17.14 Captain - Unintelligible words. Followed by a series of crashing sounds. 11.17.18 Recording stopped. - *(Speed of 142 knots/hour, at which take-off can no longer be aborted) www.acutech-consulting.com 13 Taipei Airport Runway Layout www.acutech-consulting.com 14 SQ006 Accident – Taipai www.acutech-consulting.com 15 SQ006 Accident – Taipai www.acutech-consulting.com 16 SQ006 Accident – Taipai www.acutech-consulting.com 17 SQ006 Accident – Taipai www.acutech-consulting.com 18 SQ006 Accident – Runway Debris www.acutech-consulting.com 19 SQ006 Accident – Debris Layout www.acutech-consulting.com 20 SQ006 Incident Overview – Human Factors in Design The closed runway, number 05R, did not have a barricade that made it impossible for an aircraft to take the wrong runway Runway 05R was not blocked off by barriers because part of the strip was used by landing planes to taxi back to the terminal. Runways which are closed are normally not lit up to make it clear they are not in use. But this was reported to not be the case at Chiang Kai-shek airport, where a single switch controls green lights on the common taxiway to both runways and down the middle of 05R. www.acutech-consulting.com 21 SQ006 Incident Overview – Human Factors in Design The pilot confirmed twice to the control tower that he was on the correct runway. But officials there did not know the plane had actually gone on to the wrong runway because the airport does not have ground radar and the plane was out of sight at the time of its takeoff. www.acutech-consulting.com 22 HEPs Can Be Most Effectively Reduced in Work Situation Redesign Improvement Resulting decrease in HEPs (Factors) – Good human factors – 2-10x engineering practices in design of controls, displays, and equipment. – Redesign of displays or – Over 10x controls that violate strong population stereotypes Kletz, T. A., and Whitaker, G. D., Human Error and Plant Operation, ICI, 1973 www.acutech-consulting.com 23 SQ006 Incident – Possible Sources of Human Error Pilot – Error in operation – took wrong runway despite proper instructions? Controller – Error in observation – did not track aircraft position (caused by inability to do so - no ground radar)? Construction workers and/or airport management – Error in maintenance – did not provide sufficient warning/barricades at the most effective point – at the entrance to the runway under repair? Designer – Error in design – inactive runways did not have distinct warning lights to identify closed status? www.acutech-consulting.com 24 SQ006 Incident – Possible Sources of Human Error (cont’d) Airport management – Error in operation – allowed the aircraft to take off despite weather conditions? Left construction equipment and barricades on the runway? Did not provide ground observer? Did not provide adequate signage or barricade? www.acutech-consulting.com 25 SQ006 Incident – Possible Performance Shaping Factors Weather – storm conditions with rain, high winds, limited visibility? Time of day – Nighttime with reduced visibility due to storm and darkness? Timing – Pressure to takeoff within time slot allocated? Stress – Pilot of 747 with responsibility for 157+ passengers and crew under takeoff conditions; controllers with multiple responsibilities? Limited information – controllers could not track the aircraft while on the ground; pilot could not see obstacles and had no feedback on his error? www.acutech-consulting.com 26 Performance Shaping Factors (PSF) Internal PSF’s: Training/Skill Practice/Experience Knowledge of Required Performance Standards Stress Intelligence Motivation Personality Emotional State Physical Condition/Health Culture From “A Manager’s Guide to Reducing Human Errors, Improving Human Performance in the Chemical Industry, Chemical Manufacturer’s Association, July 1990. www.acutech-consulting.com 27 Performance Shaping Factors (PSF) External PSF’s – Situational Characteristics: Architectural features Environment (noise, heat, humidity, lighting, etc.) Work hours and schedule Availability of equipment Staffing levels Actions by Supervisors Plant policies From “A Manager’s Guide to Reducing Human Errors, Improving Human Performance in the Chemical Industry, Chemical Manufacturer’s Association, July 1990. www.acutech-consulting.com 28 Performance Shaping Factors (PSF) External PSF’s – Task, Equipment, and Procedural Characteristics: Procedures (written or unwritten) Communications (written or oral) Work methods Frequency/repetitiveness Physical requirements Complexity (information overload) Feedback Hardware interface factors (design, job aids, equipment) Task criticality From “A Manager’s Guide to Reducing Human Errors, Improving Human Performance in the Chemical Industry, Chemical Manufacturer’s Association, July 1990. www.acutech-consulting.com 29 Performance Shaping Factors (PSF) Physiological/Psychiological Stressors: Fatigue Climate extremes Movement repetition Sleep deprivation High task overload Threats Negative reinforcement Lack of rewards, recognition, or benefits From “A Manager’s Guide to Reducing Human Errors, Improving Human Performance in the Chemical Industry, Chemical Manufacturer’s Association, July 1990. www.acutech-consulting.com 30 SQ006 – Preventable? Barricade at entrance to runway? Radar for tracking aircraft position on the ground? Improved runway markers and lighting? Limit operations in poor weather conditions ? Limit operations near construction areas? Observer at ground for air traffic control in poor weather conditions or during construction? Analysis of work situation and anticipation of errors? www.acutech-consulting.com 31 Human Factors in Process Safety – Understood it is a problem, but is it understood? It is understood that human factors greatly contribute to the success or failure of process safety programs in the chemical process industries But most of industry has not developed special initiatives to comprehensively address human factors. www.acutech-consulting.com 32 Human Factors – Why not a focus? Human factors has seemed too ambiguous or subjective? too involved and comprehensive? potential for high cost for redesign? too difficult to change human behavior? unnecessary – Murphy’s Law? www.acutech-consulting.com 33 Opportunity Missed? Industry may not have fully addressed what has often been characterized as the area that should receive the most attention There are ripe opportunities for risk reduction. www.acutech-consulting.com 34 How to Reduce Human Error 1. Incorporate human factors into inherently safer design practices, management practices, and into improvements in the work environment 2. Ensure human factors are imbedded into the culture 3. The key objective - to reduce the number and likelihood of situations to produce error. www.acutech-consulting.com 35 Human Factors Program Elements 1. Written human factors policy and commitment 2. Employee knowledge and involvement 3. Training on human factors and incorporating human factors in all training activities 4. Incorporating human factors into hazards analysis 5. Human factors in MOC – organizational change 6. Incident investigation and human factors root cause assessment 7. Consideration of human factors in written work procedures 8. Auditing of the human factors program performance www.acutech-consulting.com 36 Objective of a Human Factors Program To develop an employee-based system that ensures that human factors considerations are pervasive in the organization in order to reduce error-likely situations and incidents caused by human factors issues. www.acutech-consulting.com 37 Error-Likely Situations Inadequate, inoperative, or misleading instrumentation Inadequate labeling Poor lighting Poor human-equipment layout and interface Time pressures for performance No opportunities to recover from errors Inadequate physical restrictions www.acutech-consulting.com 38 Reducing Human Error by Improving the Design A formal PHA with an emphasis on human factors should identify the key error-likely situations Hazard identification is the key to program success Qualified and trained teams are normally adept at developing practical solutions to reduce risk Solutions need to be evaluated further beyond the PHA sessions www.acutech-consulting.com 39 Reducing Human Error and the Potential of Human Errors Emphasize prevention through design, policy, procedures, training Always provide for human error despite prevention efforts Provide multiple means of warning of error in the early stages of the event sequence Provide means of stopping an error before it evolves Design with layers of defense that control error outcomes www.acutech-consulting.com 40 Resource for Further Information www.acusafe.com www.acutech-consulting.com 41 This presentation is an excerpt from AcuTech’s 2-day Human Factors for Process Safety Course. To attend this course and for training on a complete range of Process Safety and Risk Management topics, contact AcuTech at: Mr. Jeremy Foutch Manager AcuTech Training Institute 100 Bush Street, Suite 200 San Francisco, CA 94104 firstname.lastname@example.org http://www.acutech-consulting.com/training/index.html Note: The opinions in this course are those of the author and do not represent an opinion on the causes of the actual incident. They are presented as an educational example only. The authors do not make any warranty, expressed or implied, or assume any liability or responsibility for any use, or the results of such use, of this information. These slides are protected by copyright, with AcuTech Consulting, Inc., owner. These slides may be distributed freely so long As they are not altered in any way and appropriate credit is given to AcuTech.