Table of Contents
Introduction
Accidents in the aviation industry, like many others elsewhere, are a result of a chain of events that culminate in the erroneous acts of the crew members (Shappell et al., 2007). Over the years, newer and better technologies have been used to promote safety in the industry. Unfortunately, the ability of these technologies to work effectively largely depends on the people using them. Human actions and omissions thus continue to play a role in aviation accidents. With a large percentage of accidents attributed to human error, it is, therefore, important that this aspect is carefully considered when analyzing aviation safety. Unfortunately, human error is elusive and becomes very difficult to understand and correct. However, the aviation industry is continuously learning from past experiences to understand the contribution of human errors in aviation accidents and how to correct this problem. Past accidents have thus provided painful but vital lessons in improving the overall safety of this industry. This report focuses on the aspect of human error in aviation accident by looking at the case of the accident involving American Airlines Flight 965 which occurred in 1995. A brief examination of the key facts surrounding the accident is given, followed by an analysis of the major findings of the report. Finally, the major learning points from the accidents are highlighted.
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Summary
American Airlines Flight 965 was a passenger flight operating between Miami International Airport in Florida and the Alfonso Bonilla Aragon International Airport in Cali, Colombia. The airplane was a Boeing 757-200, and on the fateful day of December 20, 1995, had 155 passengers on board and eight crew members (Ladkin, 1996). The plane had taken off from Miami at approximately 1835 EST after a two-hour delay. In the cockpit were Captain Nicholas Tafuri, aged 57 and the First Officer was Donald Williams aged 39. These two had received training in Latin American operations and were considered to be skilled, experienced and fit for the job. The airport in Cali, where the plane was expected to land, is surrounded by mountain ridges rising as far as 14000 feet (Ladkin, 1996). On this day, the weather had been reported as being clear, and the pilots should have had no problem getting the plane safely onto the ground. Unfortunately, though, at the time of the accident, Cali airspace did not have radar coverage and radar services. The radar had been blown up three years earlier by a gorilla group, FARC. To make the approach, several radio beacons are used to guide the pilots around the mountains surrounding the city. For the case of Flight 965, the flight management system had the beacons already programmed, and this should have helped pilots understand how to maneuver around the mountains and canyons. Because the plane had been delayed in Miami, the pilots hoped to recover some of the lost time by flying a straight-in approach to the runway 19 rather than trying to come round to runway 01 (Ladkin, 1996). The pilots then cleared the approach waypoints from the plane’s navigation computer, a mistake that proved costly. When they were asked to check back in over Tuluá, they were forced to look up in their maps because this was no longer on the flight computer. By the time they got the coordinates on the map, they had already flown passed it. The pilots attempted to make up for their errors by programming the flight computer for the next waypoint, Rozo. In doing so, however, the pilots made the plane start to fly off-course. This was caused by the mix-up of the waypoints on the map and those stored on the flight computer (Ladkin, 1996). By flying off-course, the plane had been put on a collision course with a mountain. Although the Ground Proximity Warning System activated seconds before the plane hit the mountain, the pilots did not have enough time to do something to avert the accident. The plane struck trees on the side of this mountain and crashed. It impacted the ground about 100 feet below the mountain’s ridgeline. Poor visibility and the rugged landscape meant that the wreckage was not found until the following morning. A total of 159 people lost their lives as a result of this accident (Aeronautica Civil of the Republic of Colombia, 1996). An investigation was later conducted to determine the cause of the crash. The major findings are discussed in this paper.
Aspects arising out of Human Factors principles which led to the accident
The investigations into the cause of the crash were undertaken by the Special Administrative Unit of Civil Aeronautics of Colombia. The U.S. National Transportation Safety Board, among other parties, helped in the investigation. The final findings of the report indicated that the accident was large as a result of human factors. In the aviation industry, human factors continue to be the major contributors to accidents and incidences, and as was the case with Flight 965, cause deaths. The following are the major human factors identified.
First, the crew did not perform adequate approach review. The investigations showed that there was no information showing approach briefing or the performing of the descent checklist. The position of the aircraft was not clear, and there was no dialogue on aspects such as the planned speeds, radio tuning and crossing altitudes. The captain was not aware of the meaning of ULQ, the VOR identifier for Tulua (Ladkin, 1996). In the end, the crew members did not make a full assessment of the risks and problems that were associated with the approach they took. They did not understand properly the physical features to look for and avoid, and how to effectively make the landing. As a result, the poor preparation by the crew members meant that they did not have the right information necessary for landing.
Secondly, the investigation also revealed that the Bogota controller did not tell the Cali controller that the plane was proceeding directly to Tulua VOR (Ladkin, 1996). When the Bogota controller informed Cali Approach of the arrival time, he made this announcement for three different aircraft, including the Flight 965. Unfortunately, the controller in Bogota did not tell the Cali controller that this flight is going on a direct route to Tulua VOR. This created confusion when the ‘cleared to Cali VOR’ clearance was made.
Third, the proper approach briefing was not conducted. The purpose of this briefing is to ensure that all the crew members exchange relevant information to develop a good understanding of the approach and adequately prepare for it (Aeronautica Civil of the Republic of Colombia, 1996). In this case, the investigation revealed that the only method that were discussed by the two crew members were the request by the pilot to the first officer to notify him of any language problems. In other words, the two did not effectively identify all the areas of concern well in time. Given that the first officer was new to the route, this briefing was necessary, but unfortunately, was not done.
Fourth, it was also revealed that the crew members lacked overall situational awareness (Sez, 2012). For instance, they flew past Tulua VOR as they attempted to locate it. In addition, they did not detect the plane was going off-course until it was too late. Since the first officer was new to Cali, it meant that he over relied on the captain’s experience. Also, there was a general lack of information on vertical navigation and proximity to terrain. As a result, they maintained the speed brakes deployed from approach runway change up to the time the plane crashed.
Fifth, the crew members, opted to continue with their approach to Cali despite receiving many cues alerting them of the danger of continuing with this approach.
Communication issues were also identified during the investigation. First, between the ATC and the crew, it became clear that language was a major barrier. The ATC only had Basic English skills necessary for aeronautical communications. It was difficult for the ATC to understand the exact position of the flight without verbal communication with the crew. Also, cockpit voice recordings showed that some ambiguous communications were not clarified by all the parties. Furthermore, between the first officer and the captain, communication was also a major issue. For example, the captain did not verify with the first officer the provisional path on the flight management system (FMS) display.
Finally, the crew members failed to revert to the basic radio navigation when the FMS navigation became confusing (Aeronautica Civil of the Republic of Colombia, 1996). This confusion meant that the crew members were faced with a heavy workload at the critical stage of landing.
In addition to the above human factors, the investigation also found other contributing factors that played a role in causing the accident. These can be summarized in three major points. First, since the plane had delayed in taking off from Miami, the flight crew attempted to expedite their approach in an attempt to recover lost time (Ladkin, 1996). This decision meant that the crew members were supposed to be alert and prepared to the dangers of the approach taken. Secondly, when the crew members executed the direct routing, the FMS logic dropped the intermediate fixes from the displays. At the crucial time when these fixes were needed, the computer did not have the information, and this caused the confusion that led to the accident. Finally, the FMS-generated navigational information that was different from that provided on the maps carried by the crew members.
The aftermath of the crash
Immediately after the crash, scavengers took key components of the plane such as the thrust reverses, avionics in the cockpit and other vital parts from the crash site. They were helped by the Colombian military and private helicopters (Federal Aviation Administration, n.d). Some parts were also stolen from the crash site and later appeared on the black market in Miami. A year after the crash, a court in the United States ruled that the pilots had committed willful misconduct, although this was reversed in 1999 by the court of appeal in Atlanta (Federal Aviation Administration, n.d). An American Airlines was forced to settle a high number of lawsuits brought against it by the victims’ families. Since 2002, it is required that all planes carrying more than six passengers should have the advanced terrain awareness warning system installed. The Miami-Cali route is still operated by the American Airlines under Flight 921, and using the Airbus A319.
Lessons learned
Following the accident, it the aviation industry became more aware of the Controlled Flight into Terrain Hazard (Federal Aviation Administration, n.d). This type of hazard is defined as an event whereby an airplane is inadvertently flown into water, terrain or an obstacle. To minimize the human errors associated with this hazard, many airlines increased their training of their crew for this hazard (Simmon, 1998). Many training videos were developed with the aim of increasing the crews’ awareness of the hazard.
Secondly, it was learned that it is necessary to have the FMS in aircraft to retain all fixes between the airplane’s current position and where the plane is going to (Walters, & Sumwalt, 2000). In the case of flight 965, these fixes were lost immediately after the FMS was commanded to proceed to a direct fix. This modification on the FMS equipment is necessary to aid crew members whenever they need to get back information on fixes.
Third, all navigation and approach charts used in aircraft should show the presence of terrain near airports or flight paths graphically (Federal Aviation Administration, n.d). This display would help crew members become more aware of the terrain and develop proper strategies for dealing with the challenges associated with the terrain.
Fourth, all pilots operating aircraft that are equipped with FMS should have easy access to navigation charts related to the phase of the flight well in advance of reaching that phase. This is aimed at enhancing the planning and preparedness of the crew members before reaching a particular phase of the flight.
It was also discovered that it was necessary to review the flight check requirements used by pilots operating FMS equipped planes. It became necessary to offer pilots with better training on the logic underlying the FMS logic or any other aircraft computer system before receiving certification to fly (Simmon, 1998). This training is aimed at enhancing the preparedness and understanding of the computer systems used in planes.
Finally, it is necessary to enhance the accurateness of the ground proximity warning system so that pilots are warned early enough. In the case of flight 965, this warning came about 12 seconds before impact, and this is a time too short to take any action.
Conclusion
This report has demonstrated how human errors led to the crash of the American Airlines Flight 965. Although a host of other non-human factors contributed, the mistakes made by the crew played the major role. Their lack of situational awareness stands out to be their major undoing. For the aviation industry, this accident provided vital lessons that have been used to enhance safety. Notably, the Controlled Flight into Terrain Hazard is now taken seriously, and measures have been put in place to address this challenge.
- Aeronautica Civil of the Republic of Colombia (1996). Aircraft Accident Report, Controlled Flight Into Terrain, American Airlines Flight 965, Boeing 757-233, N651AA, Near Cali, Colombia, December 20, 1995.Santaf, de BogotaD.C., Colombia.
- Federal Aviation Administration., American Airlines Flight 965 near Cali. [Online]
- Ladkin, P., 1996, ‘AA965 Cali Accident Report.’ [Online]
- Sez, E, 2012, ‘Mishaps: American Airlines 965. ’ [Online]
- Shappell et al., 2007, ‘Human Error and Commercial Aviation Accidents: An Analysis Using the Human Factors Analysis and Classification System.’ Human Factors, 49(2): pp. 227-242.
- Simmon, D.A. 1998. ‘Boeing 757 CFIT Accident at Cali, Colombia, Becomes Focus of Lessons Learned’. Flight Safety Digest, May-June, 1-19.
- Walters, J.M. & Sumwalt, R. L. 2000. El Deluvioclaims American 965. Aircraft Accident Analysis: Final Reports(pp. 51-73). New York: McGraw-Hill.