Human Factor in an Accident
“Human factors refer to environmental, organizational and job factors, as well as human and individual characteristics, which influence behavior at work in a way that can affect health and safety” (Health and Safety Executive, 2014). This definition includes three interrelated aspects that must be considered: the occupation, the employee, and the company.
The ’human factors’ to which employees and customers are subject sometimes lead to unintended errors of task management and professional judgment. They may also not deliver their practical skills at the trained level every time. The context for these errors may be simple lapses in the behavior of well-informed professionals or it may follow from an underlying failure to appreciate the full range of behavioral influences or their potential consequences. Errors may sometimes be intentional violations of varying degrees of severity and for varying motives. The organizational framework within which people function may not always be conducive to achieving the best from them – procedures may be inappropriate or ineffective (SKY Brary, 2014).
Case Study: Fokker-100 of Iran Air in January 5th 1998.
Iran Air Flight 378, a Fokker 100, departed Urmia (Orumiyeh) Airport (OMH) at 18:41 on a domestic flight to Tehran-Mehrabad Airport (THR). The flight was descending towards Tehran when the crew decided to divert to Isfahan. This was because the weather conditions at Tehran were not suitable for a landing on runway 29. Visibility was poor in snow and sleet and there was a 20-knot tailwind.
The flight positioned for an approach to runway 26 at Isfahan. There was fog in the area and the airplane descended until it landed a dry riverbed, some 8 km short of the runway.
Figure 1: Initially intended route map
Figure 2: Image of the plane after accident. Visibility is still low
Undisclosed Report
Captain A and first officer B were assigned to do the flight 378 from Tehran to Orumieh on January 5th 1998. Both crewmembers were new on this type of plane and it was their first experience on new generation of glass cockpit. Captain A had 60 hours and first officer B had only 20 hours of flight on the type. On assessment, Captain A’s record showed that he had failed during his training in the past and been grounded for quite some time and first officer B record showed that he had insufficient hours of experience on the jet.
Approaching Orumieh, they experienced a problem on the captain’s screen that shows navigation data. The captain’s navigation display intermittently switched to its default mode by itself. On the ground Orumieh engineer were advised and he fixed the problem by resetting the respective computer. Approaching Tehran the sun had already set and crew noticed the bad weather had reduced visibility and there was light snow with slippery runway. The captain of the airplane that had just landed in before them was Captain A’s instructor who passed him in the simulator test and let him come back to work again. He advised that the runway condition is poor and very slippery.
During approach, the crew noticed that several airplanes were diverting to the alternate airport Isfahan. They decided to discontinue the approach and go to Isfahan. The crew had difficulty setting up the computers of the aircraft for new destination. Closing to the alternate destination, they experienced significant pressure as the airport was very busy and they were short of fuel, the captain’s navigation display went to its default mode again that shows only basic data. Prior to final approach, they committed themselves to land, as there would be no fuel to make a go around and come back again.
On the short final approach course, the distance to runway on the captain’s display switched from eight to two miles, and the captain who was flying the aircraft became confused and nasty, and dived the plane to the ground in anticipation of not losing the runway in the last seconds, resulting to missing the minimum altitude at which a visual clue to the runaway must be obtained. At last, in total confusion, while looking for the runway, the first officer, to avoid hitting the ground, pulled the plane up and increased the power, but the main wheels of the aircraft touched the ground and the aircraft skidded on the cold and icy desert for about one mile before stopping around five miles short of runway. All 104 passengers and 9 crew members survived.
Figure 3: Hind view of the aircraft
Types of Errors and Violations
The causes of accidents in the workplace can be divided into three distinct factors: unsafe acts, unsafe conditions or a combination of both. Scientific research has shown more than 90% of workplace accidents, injuries or illnesses are linked to human factors.
Effective Human Performance is fundamental to operational safety in aviation. The majority of undesired outcomes can be attributed to the people who occupy the aviation system. They may especially occur in relation to the interface between people and complex procedures and equipment, which exist to support the safe and efficient completion of their duties.
Errors that contributed to the above accident can be classified as:
- Knowledge based error:
Both crews were unable to show the minimum standard of knowledge to set the flight management computer to guide the aircraft to the alternate due to poor training and lack of knowledge. Both of them had difficulty to interpret the default mode of navigation display, which was the basic mode of the flight showing only the necessary information to land the aircraft safely.
The crews were unaware of auto tuning of navigational aids, which is automatically changed from one to another in certain conditions, that’s why the distance to runway suddenly changed from 8 to 2 miles. Standard operating procedure clearly states to tune the appropriate navigational aid to avoid auto-change during approach preparation.
- Skill base error:
Pilots usually go down from minimum safe altitude towards the runway three miles prior to runway where the final approach fix is located and visual contact with the runway is established. The Captain suddenly noticed that it’s only two miles to the runway, and as a habit of landing at this stage of the flight went down without required visual clue.
- Violations and Rule based error
The first violation happened approaching Tehran and the Captain decided to go to alternate without checking with the tower. Preceding aircraft report was just an advisory, the airport was officially open, and decision to divert was affected and influenced by the instructor who landed in front of them and in the silence of first officer. Another unjustified violation happened before reaching the alternate destination when the aircraft went suddenly below minimum safe altitude without any visual contact to the runway.
- Organizational Gap:
The scheduling department didn’t have clear rules and regulations regarding new crew flying together. Normally scheduling should not put two inexperienced crew together, the requirement is minimum of 150 hours on almost all airlines
Recommendations
Over the past 20 years, a lot has been learnt about the origins of human failure. We can now challenge the commonly held belief that incidents and accidents are the result of a ‘human error’ by a worker in the ‘front line’. Attributing incidents to ‘human error’ has often been seen as a sufficient explanation in itself and something, which is beyond the control of managers. This view is no longer acceptable to society as a whole. Organizations must recognize that they need to consider human factors as a distinct element that must be recognized, assessed and managed effectively in order to control risks
We all make errors irrespective of how much training and experience we possess or how motivated we are to do the right thing. Failures are more serious for jobs where the consequences of errors are not protected. However, errors can occur in all tasks, not just those that are called safety-critical (Health and Safety Executive, 1999).
Thinking about potential human factor problems and planning ahead is more effective than waiting for incidents to occur and then trying to fix them after the event. Statistics have shown that companies that have correctly implemented and maintained an effective behavioral safety program have seen accident rates fall by between 40% and 70% (STS Solutions, 2014). This is a relatively high degree of significance. Ultimately, the goal is to minimize errors, and the consequences of those that remain, using either the monitoring or crosschecking of colleagues or technical solutions (SKY Brary, 2014).
The above accident shows the necessity of implementing a safety culture in all departments of an organization along with the training department. All departments and employees must strictly follow the Standard Operating Procedures, Checklists and CRM as well as retrain and debrief as necessary. Attending Human Factors seminars regularly and promoting no punishment reporting cultures are among safety nets that an organization could consider preventing any accidents.
Conclusion
It is no longer acceptable to attribute all accidents to human error. Instead, researchers have identified a better culprit that gives accidents a chance of avoidance. Human factors comprise a majority of all accidents. They should, therefore, be carefully managed to ensure that employees, their clients and the instruments of trade are safer. Every company should create a mechanism for managing human factors and follow up on it to ensure safety is guaranteed. The case study of Fokker-100 of Iran Air, which had an accident on January 5, 1998, is a good example of how human factors can influence the chances of an accident. As shown in that case, most of the human factors can at least be minimally controlled.
References Health and Safety Executive, 2014, ‘Human factors/ergonomics – Introduction to human factors.’ [online]
