HUMAN FACTORS FACT SHEET

Human Factors as a Symptom of Systematic Problems

Human Factors Fact sheet

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Moving beyond blame The idea of Human Factors (HFs) has become increasingly important in the aviation industry (Figure 2). Since aviation’s adoption of the term starting in WW2, human error has been acknowledged as one of the most common causes of aviation accidents (Example 1). Furthermore, research has shown that human error is a symptom of trouble deeper inside the system. Therefore, accident investigations need to go beyond looking at human error and attributing blame to assessing the situation in its entirety (Figure 1). Within this context, this fact sheet explores three groups of HFs. The first group consists of Human Limitations, which are internal factors that adversely affect cognitive performance. The second group consists of External Factors that adversely affect cognitive performance. Finally, the third group consists of Organizational Factors – external factors that do not directly affect cognitive performance.

Figure 1, The new view (Dekker, 2002)

Example 1: September 17th, 2014 A Ryanair Boeing 737-800 vacation flight from Leeds (UK) was on its final approach to Malaga (ES), intending to land on runway 13. At the same time, a Jet2 Boeing 737-800 was departing from the same runway. The Ryanair aircraft reached the runway as the Jet2 aircraft started its roll, and performed a go-around, making a 90 degree right turn while the Jet2 aircraft continued its standard climb. Both aircraft reached a safe altitude, but vertical separation between the two aircraft had been an unacceptable 400 ft. The CIAIAC investigated possible errors by the pilots and air traffic controllers, as well as other relevant factors contributing to the incident. They concluded that a lack of communication between pilots and air traffic controllers, combined with stress, fatigue, and a lack of awareness among air traffic controllers could contribute to similar events in the absence of technical failures1.

Old  View  Human  error  is  a  cause  of  accidents  

You  must  find  people's:  -­‐Inaccurate  assessments    -­‐Wrong  decisions  -­‐Bad  judgements  

To  explain  failure,  you  must  seek  failure  

New  View  Human  error  is  a  symptom  of  trouble  deeper  inside  a  system  

To  explain  failure,  do  not  try  to  discover  where  people  went  wrong  

Instead,  find  out  how  people's  assessments  and  acHons  made  contextual  sense  at  the  Hme  

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1970

Since WW II, HF research has become a significant area of aviation safety management. Researchers began by studying flight control, flight operations, and ergonomic and psychological investigations, moving on to knowledge implementation with the introduction of jet aircraft in the 50’s, 60’s and 70’s. HFs in accident analysis and the influence of HFs on performance and safety remained a smaller part of the research until the 1980’s.

1996-1998: ValuJet FL592 prompts the FAA to start a second regulatory response in HF research. The new documentation focuses on how to adequately address HF issues in design, the application of technology, systems, training, and procedures, alongside their growing relevance to maintenance.

2020

‘90

‘10

2000

1988: Aloha Airlines FL243 Extreme decompression due to fatigue damage was not noticed by the maintenance program.

1988: After Aloha FL243, the FAA is mandated to investigate the impact of Human Factors in nearly all areas of aviation, and to focus on their relationship with system modernization.

1996: ValuJet FL592 The aircraft crashed due to improperly packed oxygen generators that caused a fire.

1993-1994: The FAA implements its findings in Order 8300,10 of the Airworthiness Handbook, titled ‘’Human Factors Involved in Inspection and Repair in a Heavy Maintenance Environment.’’

1996: Boeing introduces MEDA and PEAT (1999) to systematically investigate Human Errors (Factors), understand contributing causes in maintenance and flight crew procedural deviations, and discover causes of incidents. 1999: Airbus introduces FSF to encourage HF research. 2000: Human Factors support for Airbus cockpits.

Beginning in 2005, the FAA, EASA and national CAAs issue HF curriculum requirements in multiple aviation regulation documents. 2009: The integration of Human Factors into Safety Management Systems (CAAP).

‘80

1977: KLM FL4805 and Pan Am 1736 collision, Tenerife A combination of conditions and miscommunication between the KLM crew and ATC caused the accident.

1977: After Spanish CAA research, the Air Line Pilots Association reinvestigates the accident to determine the influence of Human Factors.

Figure 2: Evolvement of Human Factors in aviation

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Human limitations: In emergency and normal operations Humans have their limitations, and their performance differs when they are exposed to factors such as stress. During an Air France flight from Rio de Janeiro to Paris in 2009, the aircraft stalled mid-flight and crashed into the ocean. Why did it stall? Although there were technical issues with the aircraft, and the pilot was presented with aural and visual stall warnings, the pilot continued to pull the stick backward, indicating a focus on increasing altitude. In other words, pilots in the cockpit faced a number of human limitations, resulting in the crash. Surprisingly, these limitations are also present during normal operations – and can become critical even in a normal chain of events2.

Complacency: Over-reliance on automation Complacency is defined as the uncritical satisfaction with oneself or one's achievements and it can lead to overreliance on automated systems as the operator becomes less and less vigilant while monitoring3. It can occur when an operator multitasks in a highly reliable automated environment, blindly trusting the system 4. Fatigue also has an effect on complacent

behaviour. For example, pilots can become increasingly less likely to notice stimuli in their visual field after a 12 hour overnight flight, leading to increased response times. In other words, potential dangers can go unnoticed5,6,7. In an attempt to prevent complacency, researchers have tested the effects of training. Training does improve overall performance, but unfortunately has no effect on automation-induced complacency8,9. Researchers do suggest that training focused on attention allocation strategies can mitigate complacent behaviour10.

Inattentional Blindness: Looking without seeing During everyday activities, we all look without seeing every detail – it is called Inattentional Blindness. For pilots, this can mean focusing attention on gauges but failing to notice unsuspected objects on a runway when looking through the windshield. Focusing attention on one activity can also increase the chances of being blind to change – this is called Change Blindness. Inattentional and Change Blindness are explained by the limited amount of data a person is able to process. During highly demanding tasks, we have less capacity to process change in our direct environment11. Age is also a factor. Adults are less likely to encounter Inattentional Blindness when compared with children or the elderly. The real problem is that Inattentional Blindness, like Change Blindness and Inattentional Deafness (see below), happens without us noticing it. Therefore, it is hard to fight. Some solutions include the use of safety nets, such as a division between operational and monitoring tasks.

Inattentional Deafness: During highly demanding tasks Cockpits can be noisy, and pilots can miss warning sounds or part of conversations. This is more likely to occur during demanding tasks, and is called Inattentional Deafness. The chance of suffering from Inattentional Deafness varies with the amount of attention needed for the person’s main task12. Inattentional Deafness is more likely to occur during a highly demanding visual task12, such as landing an aircraft and watching the

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instruments. It can be reduced by assigning a clear division of tasks and performing frequent general checks13.

Lack of assertiveness: Influenced by genetics and rank Lack of assertiveness occurs when a person is not self-confident enough to speak up for their rights and ideas. Researchers have shown that personality traits, including lack of assertiveness, are partly determined by genetics: 25% of children who are very shy and introverted will not change their behaviour later in life14. It has also been shown that a gap in experience or differences in military rank (e.g., the trans-cockpit authority gradient) can influence communicational behaviour. A steeper gradient is more likely to trigger passive behaviour15. Although lack of assertiveness is a global problem, its impact can be correlated with regional culture. For example, the Japanese tend to be more passive than Israelis16. Assertiveness can be improved through group courses that include role playing.

Lack of awareness: 85% of HF incidents Situation Awareness is defined as “the perception of the elements in the environment within a volume of time and space, the comprehension of their meaning and the projection of their status in the near future”17. Situation Awareness is obtained by scanning the environment and comparing the gathered results with mental models. Therefore, aspects such as communication, coordination, objective setting and feedback are essential. A lack of Situation Awareness has been implicated in 85% of all Human Factor incidents18. It can occur due to distraction, inattention and high workload. However, Situation Awareness can be improved by

implementing proven best practices, and by following ICAO recommendations and the company’s Standard Operating Procedures (SOPs).

External factors: Beyond influence and character traits The Tenerife accident on March 27th, 1977 – a runway collision between KLM and Pan Am Boeing 747’s in which 583 people died – led to one of the first investigations incorporating the study of Human Factors. These Human Factors included a lack of assertiveness and stress. The hierarchy in the cockpit of the KLM flight adversely affected the first officer’s assertiveness, making him reluctant to question the captain’s decision to take off19. The stress of the KLM crew was initiated by their duty time. The latter observation indicates that human performance and judgement can be affected by external factors that lie beyond influence and individual character.

Lack of communication: all aviation employees are susceptible Lack of communication is a failure to transmit, receive, or provide enough information to complete a task, and it occurs when people wrongly assume that certain things have already been done or said20. Maintenance engineers, ground handlers, air traffic controllers and pilots are as susceptible as anyone to this phenomenon. One prevention method is a safety net approach: never assume anything, always check with colleagues, and always build in feedback. Studies also demonstrate the simple solution of writing down important information so that it isn’t forgotten21.

Fatigue: A real cockpit phenomenon Fatigue is physical and/or mental exhaustion22, resulting in a decrement of performance. Fatigue occurs in aviation due to irregular working hours and long duty periods that lead to circadian disruptions and insufficient sleep. On average, pilots get between 1.8 and 3.7 hours of sleep on long-haul flights23. Fatigue studies show that sudden shifts between wakefulness and sleep lasting between a fraction of a second up and 30 seconds (known as

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microsleeps) also occur in the cockpit. These microsleeps are more likely to occur during long-haul flights and low-work periods. Theoretically, both pilots could be in a microsleep state simultaneously, leaving the aircraft effectively uncontrolled. Studies also show that pilots do not always notice their level of fatigue. They may doze off repeatedly while believing to have “successfully avoided the physiological realities of severe fatigue”24.

Stress: Can lead to performance decrease Stress is the subconscious response to demands placed upon a person3. Excessive stress leads to overburdening of abilities and decreases in human performance25,26. However, too little activation or arousal, which can be seen as low stress, can result in boredom which can also lead to decreased performance27. Work-related stressors include tight deadlines, innovation, lack of social support, work that requires a high attention level, and repetitive tasks. Stressors can also result from personal situations such as a death in the family member or divorce28,29,30. Stress management solutions include relaxation techniques, careful regulation of sleep, a healthy diet, and counselling.

Distraction: The danger of shifting attention Distraction occurs when our attention shifts away from our original focal point. Four types of distraction are typically described: visual, auditory, manual and cognitive18.. Distraction occurs because our mind works much faster than our hands – we are actually always thinking ahead3 – and it depends on personality, physical circumstances and the environment31. It can be countered by using a safety net consisting of a few points to remember when working on a task, a detailed check sheet at completion, marking any uncompleted work, and always going back three steps when you return to the job. Having somebody else inspect work when it is finished, double checking it yourself, and training can also help3,32.

Organizational factors: Also a contributor A Ryanair flight from Stockholm to Madrid on July 26th, 2011 had to divert due to thunderstorms. The pilots reported to ATC that they didn’t have enough fuel to reach Madrid, and that they would have to land at Valencia. It seems that Ryanair had introduced a new fuel calculation system before the flight to increase fuel efficiency. While the pilots could have added extra fuel, they were systematically asked to minimize the excess amount carried. In other words, although a lack of resources caused by weather was involved, the incident could have been prevented by both pilots and management. The Human Factors involved in this incident did not affect human performance, but adversely affected safety by imposing a restraining environment.

Lack of teamwork: SOPs and formal training can help

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Lack of teamwork is defined as the presence of interdependent individuals who do not work together or communicate well with others to achieve a common set of goals21. It is caused by individuals who do not communicate with their team members, do not know what their roles and responsibilities are, or who take individual rather than group decisions21. Standard operating procedures and formal training such as crew resource management, and commercial aviation regulations call all help to prevent accidents where lack of teamwork is involved.

Norms: Negative norms can occur during routine work “Norms is short for ‘Normal’, or the way things are actually done within an organization3. In other words, they are unwritten rules followed or tolerated by the majority of a group. Negative norms are those that detract from an established safety standard. This kind of human error occurs mainly due to routine work, alternative norms made by employees, or functioning in a non-approved manner. Unofficial norms occur when they remain in the organization for an extended period of time. While it is management’s role to correct employee behaviour directly when it is contrary to safety, management ultimately tends to tolerate the norms made by employees21. Countermeasures can include the elimination of shortcuts, awareness of our own bad habits, an emphasis on positive things to eliminate negative things, and setting an example for other people.

Lack of resources: Can be avoided In aviation maintenance, resources are the tools or materials required to maintain and/or inspect aircraft. The prevention of accidents due to a lack of resources depends on ordering equipment before it is required, pre-knowledge of available equipment sources, and arranging pooling or loaning. The time schedule for completing an aircraft maintenance task must also be sufficient33.

Lack of knowledge: Invest in training A lack of knowledge indicates that one does not have the knowledge, skills or experience to perform the job34. For instance, aircraft maintenance procedures must be performed in accordance with standards specified by aircraft manufacturers, airlines and authorities (FAA, EASA and ICAO). Changes in these procedures occur regularly, so management should invest in regular training to keep employees up-to-date with the quickly changing aviation environment35. The latest manuals should be available to ensure that the right procedures are executed. People should also be free to ask for help when something is unclear34.

Pressure: Match time to difficulty Pressure it to be expected when working with a people and systems. However, when pressure builds to the point at which it stands in the way of completing a necessary task timely and correctly, then it becomes a threat to safety. The most common form of pressure is time pressure, which causes people to take more risks and make more decisions based on heuristic recognition rather than using available knowledge36,37,38. Task difficulty and available time need to be well regulated to make sure employees are not under needless pressure when performing their tasks. Organizational aspects

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such as working hours should be taken into account when designing solutions to reduce incidents and accidents in aviation.

Nobody goes to work to do a bad job People who look at an event after it occurs often claim that they could have easily predicted the event in advance if they had been asked to do so39. Complete scenarios are often overlooked as investigations regularly point to Human Factors as the problem, instead of their underlying causes. Human error is not an explanation for failure…it demands an explanation40. Therefore, investigations should not focus on attributing blame. Instead, investigators should ask ‘why it made sense to make a mistake’41. The investigation of factors that easily disappear behind the label “human error” should therefore be encouraged. After all, “Nobody goes to work to do a bad job” – William Edwards Deming.

 

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registered EI-EB and Boeing 737-800, registered G-GDFR, at Malaga Airport.

2 Bureau d’Enquête d’Analyses (2012). Final Report on the Accident on 1st June 2009 to the Airbus A330-203, registered F-GZCP, operated by Air France, flight AF 447 Rio de Janeiro – Paris.

3 Dupont, G. (1997). The dirty dozen errors in aviation maintenance. In Meeting Proceedings Eleventh Federal Aviation Administration Meeting on Human Factors Issues in Aircraft Maintenance and Inspection: Human error in aviation maintenance (pp. 45-49). Washington, DC: Federal Aviation Administration/Office of Aviation Medicine.

4 Corver, S. C., & Aneziris, O. N. (2014). The impact of controller support tools in enroute air traffic control on cognitive error modes: A comparative analysis in two operational environments. Safety Science,

5 Russo, M.B., Sing, H., Santiago, S., Kendall, A.P., Johnson, D., Thorne, D., Escolas, S.M., Holland, D., Hall, S., Redmond, D. (2004). Visual Neglect: Occurance and Patterns in Pilots in a Simulated Overnight Flight. Aviation, Space and Environmental Medicine (ASEM), 75(4), 323-332

6 Petrilli, R. M., Roach, G. D., Dawson, D., & Lamond, N. (2006). The sleep, subjective fatigue, and sustained attention of commercial airline pilots during an international pattern. Chronobiology international, 23(6), 1357-1362.

7 Hartzler, B. M. (2014). Fatigue on the flight deck: The consequences of sleep loss and the benefits of napping. Accident and Analysis Prevention, 62, 309-318.

8 Singh, I. L., Sharma, H. O., & Parasuraman, R. (2001). Effects of manual training and automation reliability on automation induced complacency in flight simulation task. PSYCHOLOGICAL STUDIES-UNIVERSITY OF CALICUT,46(1/2), 21-27.

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9 Singh, A. L., Tiwari, T., & Singh, I. L. (2009). Effects of automation reliability and training on automation-induced complacency and perceived mental workload. Journal of the Indian Academy of Applied Psychology, 35 (Special Issue), 9-22.

10 Parasuraman, R., & Manzey, D. H. (2010). Complacency and bias in human use of automation: An attentional integration. Human Factors, 52(3), 381-410. doi:10.1177/0018720810376055

11 Lavie N, Hirst A, de Fockert J. W. & Viding E. (2004). Load Theory of Selective Attention and Cognitive Control. Journal of Experimental Psychology Vol. 133, No. 3, 339–354

12 S.P. Macdonald, J., & Lavie, N. (2011, May 25). Visual perceptual load induces inattentional deafness. Retrieved from Springer: http://link.springer.com/article/10.3758%2Fs13414-011-0144-4

13 Cartwright-Finch, U., & Lavie, N. (2007). The role of perceptual load in inattentional blindness. Cognition, 102(3), 321-340.

14. Kagan, S. (2011). Kagan cooperative learning. California. Kagan Publishing.

15 Chua, R.Y.J., Iyengar, S.S., (2011). Perceiving freedom givers: Effects of granting decision latitude on personality and leadership perceptions. The Leadership Quarterly, 22(5), 863-880

16 Zimbardo, P. G. (1990). Shyness: What it is, what to do about it. Da Capo Press.

17 Endsley, M.R. & Garland, D.J. (2000). Pilot situation awareness training in general aviation. In proceedings of the 14th triennial congress of the international ergonomics association and the 44td annual meeting of the human factors and ergonomics society. Santa Monica, CA: HFES.

18 ATSB, A. T. (2004). Dangerous Distraction; an examination of accidents and incidents involving pilot distraction in Australia between 1997 and 2004. Australian Transport Safety Bureau.

19 Airline Pilots Association, (1977). Human Factors Report on the Tenerife Accident. Retreived from Skybrary: http://www.skybrary.aero/bookshelf/books/35.pdf

20 Shorrock, S. T. (2007). Errors of perception in air traffic control. Safety science,45(8), 890-904.

21 Peterson, J. (2011). Dirtydozen. Retrieved October 9, 2014

22 The Free Dictionary - Fatigue. (n.d.). Retrieved from The Free Dictionary: http://www.thefreedictionary.com/fatigue

23 Roach, Darwent, Sletten, & Dawson. (2010). Long-haul pilots use in-flight napping as a countermeasure to fatigue. Elsevier, 214-218.

24. Caldwell. (2004). Travel Medicine and Infectious Disease. Elsevier, 85-96.

25 Arshadi, N., & Damiri, H. (2013). The relationship of job stress with turnover intention and job performance: Moderating role of OBSE. Procedia - Social and Behavioral Sciences, 84(0), 706-710.

26 Cowan, R., Sanditov, B., & Weehuizen, R. (2011). Productivity effects of innovation, stress and social relations. Journal of Economic Behavior & Organization, 79(3), 165-182.

27 Cowan, M., Davie, A., & Migaud, H. (2011). The effect of metal halide and novel green cathode lights on the stress response, innate immunity, eye structure and feeding activity of Atlantic cod, Gadus morhua L.

28 Cowan, M., Davie, A., & Migaud, H. (2011). The effect of metal halide and novel green cathode lights on the stress response, innate immunity, eye structure and feeding activity of Atlantic cod, Gadus morhua L

29 Saldana, Rodriguez, & Ritzel. (2012). Influence of task demands on occupational stress: Gender differences. Elsevier, 365–374.

30 García-Herrero, S., Mariscal, M. A., Gutiérrez, J. M., & Ritzel, D. O. (2013). Using bayesian networks to analyze occupational stress caused by work demands: Preventing stress through social support. Accident Analysis & Prevention, 57(0), 114-123.

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error-report-web.jpg

31 Young, K., Lee, J. D., & Regan, M. A. (2009). Driver Distraction: Theory, Effects, and Mitigation. Taylor & Francis Group, LLC.

32 Marss. (2009). The "Dirty Dozen" in Aviation Maintenance. Opgehaald van Aviation Knowlegde : http://aviationknowledge.wikidot.com/aviation:dirty-dozen

33 Concetti, M., & Fedele, L. (2011). 2. Safety in Maintenance: errors and human factors. Healthy Workplaces, 11.

34 Airplane Flying Handbook. (2004). U.S. Department of Transportation Federal Aviation Administration.

35 Taylor, D. (2012). Retrieved from AviationLearning.net: http://www.aviation-training-consultants.com

36 Koslowsky, M., Kluger, A.N., Reich, M., 1995. Commuting Stress: Causes, Effects, and Methods of Coping. Plenum, New York.

37 Hilbig, B.E., Erdfelder, E., Pohl, R.F., (2012). A matter of time: Antecedents of one reason decision making based on recognition. Acta Psychologica, 141(1), 9-16

38 Young, D. L., Goodie, A. S., Hall, D. B., & Wu, E. (2012). Decision making under time pressure, modeled in a prospect theory framework. Organizational Behavior and Human Decision Processes, 118(2), 179-188.

39 Guilmette, T.J., Hart, K., (1988). Eliminating the Hindsight Bias. Journal of Applied Psychology, 73(2), 305-307

40 Dekker, S.W.A. (2002). Reconstructing human contributions to accidents: the new view on error and performance. Journal of Safety Research, 33(1), 371-385Arkes, H.R., Faust, D.,

41 Leveson, N. G. (2012). Engineering a safer world: Systems thinking applied to safety. The MIT Press. Retrieved from http://rps.hva.nl:2307/book/id_47540/book.asp

This is a Luchtvaartfeiten.nl / AviationFacts.eu publication. Authors: Honours programme in Aviation Engineering; Students 2014/2015 Editorial staff: R.J. de Boer PhD Msc, G. Boosten MSc & G.J.S. Vlaming MSc Copying texts is allowed. Please cite: ‘Luchtvaartfeiten.nl (2015), Human Factors Fact sheet, www.luchtvaartfeiten.nl’ Luchtvaartfeiten.nl is an initiative by the Aviation Academy at the Amsterdam University of Applied Sciences (HvA). Students and teachers share knowledge with politicians and the general public to ensure that discussions are based on facts. October 2014 Revised January 2015