Human Factors In Aviation Accidents

Abstract

This paper describes the different aspects of human factors in the aviation industry and the roles that these factors play. Human factors are always present in accidents; it is the investigator that has the task of deciphering just what role they played in the accident.

In this paper the discussion and research will be focused on the human factors of the flight crew and the various sources of contribution to those factors.

Human Factors in Aviation Accidents

Aviation is arguably, by nature, a very unforgiving and dangerous environment. The weakest link in the man machine interface is human factors. Human factors in aviation are a very profound and intense subject that is discussed, debated and written about by many people and at great length. There are many contributors that make up the general term "human factors". Human factors as applied to aviation can cover human capabilities, system analysis and design, control and automation, skill acquisition, information processing and display, crew workload, and task-induced stress, human-machine interaction, environmental effects on performance, psychological and physiological influences, and accident prevention (Human Factors in Aviation Safety, 2007).

In 76 % of accidents over the 30 years prior to 1989 the main casual factors were determined to be due to cockpit crew human errors. In 1988, 80% of aircraft losses were classified as being due to human factor errors. It has been suggested that the primary cause in many accidents is the Captain's failure to control and the Co-pilots failure to monitor. Crew members are the final opportunity to stop errors, but the crew is also human (Human Factors in Aviation Safety). While these statistics are the results of a specific research that was conducted, this is supported by the basic, yet broad belief any aircraft accident involves the aircraft and the aircrew.

In an investigation done by the Bureau of Air Safety Investigation (BASI), they took 75 fatal airplane accidents from their data base and concluded that 36% of the accidents came from the private/business jet sector of Aviation. From this 36% they said that 72% of the accidents involved pilot action (Human Factors in Fatal Aircraft Accidents, 1996). The remaining contributing factors were weather and "other personnel" which includes air traffic control, flight crew and maintenance personnel. It is important to take those aspects into consideration and not to focus on pilot error or action alone. Many times a pilot is faced with the dilemma of correcting or controlling a situation that was introduced to him with absolutely no warning, leaving him with an incredible disadvantage. Every investigator has the task of deciphering to what extent the pilot's role in the accident was.

Pilot Factors

This analysis will compare and evaluate factors for both accidents induced by pilot errors and those where pilot error was a contributor but not the initiating event. Pilot induced accidents are those initiated by an inappropriate action of the aircrew. That is, the National Transportation Safety Board (NTSB) report of the accident cited pilot error first within its analysis covering accident causes, factors, and findings. Pilot contributed accidents are those accidents with outside influences that introduce the pilot to the scene. Typically some other force such as weather, aircraft failure, etc initiates them. If the NTSB report accident cited pilot error within its analysis after considering these factors, these accidents should have been recoverable, but the aircrew failed to take appropriate actions or took inappropriate actions.

Factors contributing to pilot error can be extremely broad and cover completely different ends of the spectrum. These factors can be poor judgment, diverted attention, inadequate preflight preparation or planning and operating beyond experience and ability.

Poor judgment can be an issue of perhaps just focusing too much on one problem when multiple situations are present. One example in the research conducted by BASI told of an experienced pilot that was so distracted by a malfunctioning landing gear that he eventually ran out of fuel (Human Factors in Fatal Aircraft Accidents). An experienced pilot can also fall victim to diverted attention, he can become distracted by a malfunctioning system and become less aware of other factors, such as wires, causing a wire strike, or just missing other aspects of the flight. When faced with a problem in-flight, an error in judgment is basically made one of two ways. The pilot can have an incorrect interpretation of the problem, inevitably leading to the wrong decision because the crew is solving the wrong problem, or he assesses the situation correctly and chooses the wrong solution or course of action (Wiley, 2003).

Accidents that occur due to inadequate flight preparation are often one of the hardest to understand. When performing the preflight inspection, an absolute essential part of the checklist, it is imperative that one is as thorough as can be. Attention to detail pays off, and it should include going over maintenance discrepancies as well. How devastating it was to research this topic and read about the pilot that reported the aircraft had lost lateral control during takeoff. While he reduced power and landed the aircraft off the side of the runway, the aircraft stalled, endured a hard landing and was severely damaged. Upon investigating the incident, it was found that the ailerons were not operative because they were not connected during the preflight inspection (Fly Baby Accident Reports, 2007).

When an accident occurs due to performing outside the pilot's capabilities and experience, there are a few aspects of this to consider. Was the pilot faced with a scenario that caused him to react in a way he didn't have any familiarity with? Was the pilot hot-dogging? While it is not wise to go thousands of feet above the ground to show off in a million dollar vehicle, one would have to wonder if there are psychological factors playing into that decision.

Psychological versus Physiological Factors

Psychological factors are one of the hardest aspects of an investigation. Psychological factors are those factors that impose an additional processing load in the conscious brain. When these factors are present, the pilot may experience overload; a condition where there is more information that must be processed than the conscious brain can handle (Leland, 2007). The investigator has to know the persons state of mind at the time of the accident, even the time leading up to the accident. Rarely does an accident leave us clues of mental state but that does not