Overrun Accident of The American Airlines Flight 1420
Abstract
The American Airlines accident Flight 1420 is identified as a runway overrun accident. The National Transportation Safety Board conducted an investigation to find the cause. This project is primarily focused on the human factor issue that might have caused the accident. The project explored the Human Factor Analysis and Classification System and used the Swiss Cheese Model to link the chain of events to determine the cause of the accident.
The Human Factor Analysis and Classification System was used by the National Transportation Safety Board to analyze the human factors issues within American Airlines Flight 1420. This system proved to be very successful in analyzing how the accident occurred. The Human Factor Analysis and Classification System combined with the Swiss Cheese model explained how one things related to another and how organizational policies and resources were not followed. The report found that inadequate supervision, combined with preexisting conditions like bad weather and fatigued flight crews had caused misjudgment and errors that ultimately affected the landing.
On June 1, 1999, American Airlines Flight 1420 (Flight 1420) was on its way to the Little Rock National Airport. Flight 1420’s pilot was very experienced, with more with more than 10,000 total flight hours. The National Transportation Safety Board (2001) stated that the airplane used during the flight was a “McDonnell Douglas DC-9-82 [MD-82]” (NTSB, 2001). The airplane was supposed to land ten minutes before midnight. The airplane landed according to schedule, however the airplane failed to stop before the end of the runway. There was a severe storm that night, and visibility was at a minimum. The MD-82 overran the end of Runway 4R and collided with a structure supporting Runway 22L. The NTSB (2001), reported that the plane struck the approach lighting system, killing the captain and 10 passengers (NTSB, 2001). The post-impact fire then destroyed the remaining of the airplane, with the fuselage area having the worst fire damage. Luckily, the emergency team successfully saved more than ninety percent of the people onboard.
The United States National Transportation Safety Board arrived at the crash scene immediately and conducted interviews and investigation with crewmembers, eyewitnesses and passengers. The NTSB found that the aircraft spoiler did not open properly during the landing. This error reduced the airplane braking power significantly. The NTSB found no preexisting mechanical condition on the airplane or any lack of training with the crew. Crew members were properly certificated and qualified. Furthermore according to the NTSB (2001), there was no evidence indicating intoxication or medication that would affect the crews’ performance (NTSB, 2001). The NTSB did find however that crew members were very close to over time limitations. Wiegmann (2001) states that human issue was indeed a major issue that contributed to Flight 1420’s accident (Wiegmann, 2001). The NTSB then conducted an investigation using the Human Factor Analysis and Classification System. The investigation focused on finding the human factor issue within Flight 1420. The NTSB reviewed organizational influences on that day, followed by unsafe supervisions, preexisting condition to the crews and also any unsafe acts that happened during the landing of the MD-82 airplane.
The first step involved investigating what could have caused the crew to force the landing. The investigation found that stormy weather, low visibility and wind shear could have affected the airplane’s landing at any moment. According to the NTSB operating manual (2001), “The nonflying pilot is responsible for announcing that the spoiler lever has been armed and that the spoilers should not be armed if the ‘Auto Spoiler Do Not Use’ light is illuminated” (NTSB, 2001). There was no reference found however that showed which pilot was responsible for physically arming the spoiler level. The investigation concluded that the American Airlines pilots had no clear guidelines in place for arming the auto spoiler system; which created the culture that the captain was the responsible for arming the system.
The pilots on Flight 1420 had been flying for a while and were very near their overtime limit. The pilots were forced to land as soon as possible or would be in violation of the American Airlines’ duty time limitation. This was important according to the NTSB (2001) especially after the plane took off over two hours later than the scheduled departure time (NTSB, 2001). The crew did receive prior precautions and warnings concerning the weather. The NTSB (2001) stated that “trip paperwork for the flight with the American Airlines weather advisory [advised] for a widely scattered area of thunderstorms along the planned route” (NTSB, 2001). The crew received the required resources support from American Airlines, however there were unclear organizational processes. There was confusion on the landing procedure, specifically on who was responsible for arming the auto spoiler, as that process was not sufficient nor clear enough.
The Air Traffic Controllers were not provided with the near-real-time color weather, which could show precipitation intensity to better represent the weather condition surrounding the airport. The flight dispatchers were not optimized since they had no access to needed information. The dispatchers did not have information for the Terminal Doppler Weather Radar system nor the Weather Systems Processor information. These findings concluded that ground personnel did not have enough available resources to be used in supporting the flight crews.
The next step on the Human Factor Analysis and Classification System is the supervision aspect. This step reviews how the crews analyzed the risks like the wind shear or the very low visibility toward the runway location. During the landing of the American Airlines Flight 1420, the crews failed to assess the level of risk they would be facing by landing at the Little Rock National Airport that night. The NTSB (2001) reported that interviews with the airport staff proved that the crews received enough information regarding the landing situation and the wet runway, including the possibility of wind shear level appears on the airport area (NTSB, 2001). The crews however ignored all the warnings and continued their effort to land at the airport despite the bad circumstances, which were worsened by the low visibility.
The captain failed to enforce his roles as the most authorized person on the airplane to make a call to cancel the landing and seek an alternate landing location. There was no clear leadership in the cockpit as both pilots were afraid of violating the duty time limitations. The NTSB (2001) found that “during the landing, the crews were found using the thrust reversal
system above 1.3 Engine Pressure Ratio [EPR] on wet runways reducing the functionality
of important directional control from the rudder, despite the training they had received
The personnel management failed on assigning one pilot to arm the auto spoiler as there was no
definitive organizational culture or and policy on the matter. All of the supervision systems that was supposed to prevent the accident failed, which formed a chain that caused the accident.
The next step is the preexisting conditions in American Airlines Flight 1420. The preexisting environmental factors were the weather conditions and the workload of the crew. These factors severely affected the crews’ performance during the landing procedure. The crews’ performance was significantly limited by bad weather and poor visibility prior to the landing. Another issue was that crew members did not weigh the situation appropriately. According to the NTSB (2001), “the flight crewmembers’ focus on expediting the landing [due to] impending weather contributed to their degraded performance” (NTSB, 2001). The pilot relied solely on the automation system, which caused him to not check if the ground spoiler was working properly.
The personnel factors were divided into coordination and self-imposed stress. The coordination of the crew was sufficient in the beginning. However, the crew members begin to rush and not complete mandatory checks. None of the crew members verified whether the spoilers were deployed or not after touch down. Task delegation was also an issue because the flight crews were facing heavy workloads; while also realizing that they were getting closer to the runway. The self-imposed stress was the inadequate rest the crews had during the flight. The crew members were fatigued from the previous flights and wanted to land as soon as possible to achieve their mission and not violate the duty time limit regulation. The actions of the crew members were not considered their best during the flight. Prior to the landing, the crews were confused on finding the location of the runway. The Cockpit Voice Recorder proved that the captain was in a geographic disorientation situation as he was unsure about his airplane’s location in relation to the airport’s runway.
The Get-Home-Itis psycho behavioral was identified as well. This is a syndrome where the pilots try to land a plane or get to a location at all costs. In the Get-Home-Itis syndrome, pilots may use poor judgement and make hasty decisions in order to get home. Finnegan (2010) states that “every pilot has been in similar situations. On duty for days, feeling responsible for the asset entrusted to [their] care, commitments at home, responsibilities that needattention, fear of retribution for ‘wimping out’ by delaying a flight or waiting out a storm” (Finnegan, 2010). Even though these things get might get hectic on the airplane, the pilot must remain calm in order to perform their jobs. The pilots must remember that their first priority is to ensure the safety of the passengers and crew, and that every landing is safe.
The last step in the HFACS is to identify the actions the pilot chose during the flight. The actions are divided into errors and violations. Both pilots failed to complete a risk assessment. Their decision to continue the landing despite the wind shear situation and poor visibility was considered a by the NTSB (2001) as “decision error” (NTSB, 2001). The crews were also found to be not in compliance with stated procedures. These were skill-based errors, as no one conducted the visual scan to check whether the auto spoiler was armed or whether the spoiler was deployed or not. The pilot also failed in judging the flight duration. The pilots thought that they would be able to reach their destination before the bad weather situation occurred.
There were several factors that contributed to the crash of American Airlines Flight 1420. The failures within the American Airlines organization included unclear procedures, tired flight crew, and bad weather. The appropriate landing procedure and the responsibility of who was to arm the ground spoiler for landing was not clearly defined. In addition, the preexisting condition of the fatigued flight crew and the inclement weather caused the errors in conducting their duty.
References
Aircraft Accident Report, AAR-01-02. (2001, October 23). Retrieved April 20, 2015, from
http://www.ntsb.gov/investigations/AccidentReports/Reports/AAR0102.pdf
Finnegan, J. (2010, May 1). Get home-itis. Retrieved March 31, 2016, from
http://www.aviationtoday.com/rw/commercial/ems/Get-home-itis_67820.html#.Vv1zgssUXIU
Wiegmann, D., & Shappell, S. (2001, February 1). A Human Error Analysis of Commercial
Aviation Accidents Using the Human Factors Analysis and Classification System (HFACS). Retrieved April 24, 2015, from http://www.faa.gov/data_research/research/med_humanfacs/oamtechreports/2000s/media/0103.pdf
