Human Factors Case Study - Human Error vs Human Factors Singapore by gzn12524

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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
                 AcuTech Consulting, Inc.
                 100 Bush Street, Suite 200
                 San Francisco, CA 94104
  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:

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
 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??

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?

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?

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.

Human Error Types

1.   Intentional – deliberately commit or omit the prescribed
2.   Unintentional – committed or omitted with no prior

     From “A Manager’s Guide to Reducing Human Errors, Improving Human Performance in the Chemical Industry, Chemical Manufacturer’s Association,
     July 1990.

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

   [1] Reducing Error and Influencing Behavior, HSG48, HSE (1999).

Human and Organizational Factors

 Human and organizational factors can be related to the
  individuals that design, construct, operate, and maintain
  the system.[3]

  [3] 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

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

SQ006 Accident – 747-400

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)

Taipei Airport Runway Layout

SQ006 Accident – Taipai

SQ006 Accident – Taipai

SQ006 Accident – Taipai

SQ006 Accident – Taipai

SQ006 Accident – Runway Debris

SQ006 Accident – Debris Layout

 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.

 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.

HEPs Can Be Most Effectively
Reduced in Work Situation Redesign

   Improvement                                       Resulting decrease in HEPs
     – 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

     SQ006 Incident –
     Possible Sources of Human Error
   Pilot –
      Error in operation – took wrong runway despite proper
   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?

 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?

   SQ006 Incident – Possible
   Performance Shaping Factors
 Weather – storm conditions with rain, high winds, limited
 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
 Limited information – controllers could not track the aircraft
  while on the ground; pilot could not see obstacles and had no
  feedback on his error?

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.

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.

Performance Shaping Factors (PSF)

   External PSF’s – Task, Equipment, and Procedural
           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

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.

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?

Human Factors in Process Safety –
Understood it is a problem, but is it

 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.

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?

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.

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.

     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
7.   Consideration of human factors in written work
8.   Auditing of the human factors program performance
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.

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

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

Reducing Human Error and the
Potential of Human Errors

   Emphasize prevention through design, policy,
    procedures, training
   Always provide for human error despite prevention
   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

Resource for Further Information

   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
       AcuTech Training Institute
       100 Bush Street, Suite 200
       San Francisco, CA 94104

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.

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