Aviation Accident - Alaska Airline Flight 261 - Term Paper Example

Aviation Accident: Alaska Airline Flight 261 Introduction An aircraft accident, as defined by the Convention on International Civil Aviation, is “an occurrence associated with the operation of an aircraft that takes place between the time a person boards an aircraft with the intention of flight to such a time all such persons have disembarked, where a person is fatally or seriously injured, the aircraft sustains damage or structural failure or the aircraft is missing or is completely inaccessible (Annex 13 to the Convention on International Civil Aviation, November 2001 p. 10).” It is usually an unexpected and disastrous event. Since the invention of aircrafts, many accidents have occurred. The major causes of these accidents are pilot error, mechanical error, weather, sabotage and other human factor like negligence. When these accidents occurs National Transport Security Board (NTSB) do carry out investigations concerning the related accident. Important information can be retrieved from the aircraft’s black box. The black box contains flight data recorder and cockpit voice recorder. The design of the black box is such that it is resistant to any physical damage. Based on actual true findings, a case of an aircraft accident of Alaska Airline flight 261 is going to be elaborated. Aviation Accident of Alaska Airline Flight 261 Flight History On January 31, 2000 about 1621 Pacific Standard Time (PST), Alaska airline flight 261 crashed into Pacific Ocean North of Anacapa Island California. The aircraft was a McDonnell Douglas MD 83. On board were 2 pilots, 3 cabin crew members and 83 passengers, which included 3 infants who were lap-held by their parents and as such they did not have safety belts. All perished and the aircraft was ruined upon impact as the plane plunged into the ocean due to the high descending speed ( about 250 miles/hour) and extreme stress forces. The aircraft was shattered to pieces as it hits the water. Flight 261 was operating a planned international flight, which was heading from Lic Gustavo Diaz Ordaz International Airport, Mexico to Seattle Tacoma International Airport (SEA), San Francisco California. Shortly after takeoff, the experienced pilots got the first sign of trouble. The horizontal stabilizer located on the tail plane would not move and they tried carrying out a standard checklist to check if they would free up the stabilizer. The horizontal stabilizer on the MD is 40 feet surface mounted on top of the vertical stabilizer, which acts as another wing. Its main purpose is to adjust the angle of the plane during flying. The jammed stabilizer pushed the aircraft down towards the ground. At 28,500ft, the pilots switched off the autopilot and flew the aircraft manually, as a measure from the standard checklist. They had to pull hard the control column to push the nose of the plane up. It required physical effort by the pilot. The plane climbs for next 7 minutes to a 32,000 ft cruising altitude. It is then that they contacted the airlines maintenance department for assistance. However, several minutes after requesting help from the ground they got no advice. The pilots on the crippled plane were flying manually at 32,000 ft with a plane that has a jammed stabilizer. The pilots tried to activate the stabilizer by switching on both the electric motors that controls the stabilizer and soon after, flight 261 plunges downwards over a minute. The pilots battle for control in which they pushed the aircraft nose down into the dive to regain the dive. They slowly regained the aircraft stability at around 26,000 ft. They engaged speed breaks. It was not easy for them as the aircraft pushed its nose down. The pilots flew with all their might. The planes fate hanged on the strength of their hands. They tried to fight with the plane speed so that they could land. With the plane under temporarily control, the pilots made a fateful decision to do further trouble shooting. They needed a blank of full airspace in case they lose control again. After trying the switches once more they realized it was not a mere electrical fault but rather a serious mechanical fault. They concentrated on fixing the plane though they did know what exactly the problem was. They asked Los Angeles Airport for emergency landing and so they tried to reduce the plane to a speed of 180 knots, which is the landing speed. As they tried to land, something gave away at the tail of the plane. Everything went haywire; the plane dived straight away from 18,000 ft. The plane rolled and descended upside down. The pilot had difficulty reaching the controls but it was all gone. The aircraft was shattered to pieces as it hits the Pacific Ocean. The Investigation Federal Aviation Regulations affecting the accident Due to the flight 261 Alaska airline accident, the Federal Aviation Administration conducted a special inspection on Alaska Airline from April 3 to April 19 2000 (Custard, 2003). The purpose of the inspection was to determine the company’s compliance with the Federal Aviation Regulations (FAR’s). A member of the FAA’s system process audit staff from Washington Dc headed the inspection team together with its team members. In addition, several FAA inspectors from the Seattle Flight Standards District office (FSDO) and Certificate Management Office (CMO) were present. The 15-member team focused on Alaska Airlines maintenance and operations. According to the NTSB, the following Inspection Report findings affected the accident plane in one way or another: Maintenance training- maintenance training curriculums or on-the -job training (OJT) procedures or objectives is not specified on the Alaska Airline training manual. The program to be followed by the trainees is unofficial and usually administered at the discretion of the instructors. The program has no criteria for successful completion given, not structured and no identification of subjects to be covered. Continuous Analysis and surveillance program- Facsimiles of audit checklists are missing in the Alaska Airline manuals, which are being used to administer the program. Gathering of data is not continuous but intermittent in which audits are performed at intervals of 12 or 24 month, and allowance of a 6-month extension is available (Soucie and Cheek, 2011). Lack of management personnel- For two years (since 6/12/98) there has been a vacant seat for the Director of Maintenance .At the time of inspection two people were sharing the two seats. The director of Operations seat was also vacant. The Director of Safety was also the Director of Quality Control and Training. That position was not reporting directly to the highest level of management. Maintenance Program-Procedures that the company was actually using to perform maintenance on its aircraft at the company’s maintenance facilities did not reflect at the General Maintenance Manual (GMM). Procedures for the issuance of an airworthiness release to an aircraft coming out of a heavy check were not contained in the GMM (Krause, 2003). Without the completion of all necessary paper work, two aircraft were released from service from a C check. The inspection team questioned aircraft’s completion of work, before it is issued an airworthiness release. Numerous discrepancies were revealed concerning spot checks of Alaska Airline shelf program for consumables with the expiration dates that were exceeded or mislabeled. As required by the GMM, the shift turnover forms were not being used consistently. Forms that were being used were incomplete and missing required signatures. Despite the GMM requirement of signing non-routine work cards with actual signatures, this measure was not observed. Deletion and modification of work cards were observed without the approval of engineering or quality control. Mechanics on the floor were making their own changes. The report also revealed that the area that showed the highest potential of systems breakdowns was in the Maintenance Program. This was because of Alaska Airlines maintenance personnel who were not following the procedures that the company had set in the manuals thereby increasing the probability for errors. The report also revealed that by lacking a functional continuing analysis and surveillance program, several other areas suffer from the lack of oversight and reform. This was evident at the airline. It is controlled by the Quality Assurance department, which seemed to be understaffed. Problem areas were not identified because of lack of completing audits in a timely manner. The special inspection team concluded the following about Alaska Airline: The Airline’s failure to adhere to the set out procedures of practice resulted in the accident. Ineffective controls in place, which was measured by the number of findings that the team had during the inspection. The authority and responsibilities were not well defined. This evidenced by the three positions (the director of maintenance, the director of operations and the director of safety) are not filled. Two people filling two positions but duties and responsibilities not made in the GMM and there was confusion as to who is responsible for what tasks. Deferral control system was missing. Items were being deferred without using the approved MEL (minimum equipment list) which leads to items not being repaired for long periods. Ineffectiveness of quality control and quality assurance programs was a factor in the accident as was evident through things like C check packages that were without signatures. Report on National Transportation Safety Board (NTSB) findings and Recommendations. Based on the information retrieved from the cockpit voice recorder, flight data recorder and the various inspection carried out at the Alaska Airline, the National Transportation Safety Board, learned many numerous maintenance related actions that supported the findings of the FAA’s. The board found out the following issues during the investigations: Extension of end play check interval-Though manufacturer’s recommended calendar time for carrying out check C was 30 months, Alaska Airline extended its check from 26-30 months ,yet their airplane utilization rate was high. Due to this high utilization of the airplane they were supposed to carry out their check at 7000 or 7200 flight hour interval but the flight 261 accident occurred almost 9000 flight hours after the accident jackscrew assembly’s last end play check (Soucie and Cheek, 2011). If Alaska Airline had adopted the Boeing’s flight hour intervals, the jackscrew would have undergone an endplay check 1800 to 2000 flight hours before the accident occurred because it might have been removed at the time of having excessive end play measurement. Grease change from Mobil grease 28 to Aero shell 33- The process of oil replacement from Mobil 28 to Aero shell 33 on the company’s maintenance cards for the MD 80 was procedurally and substantively deficient in several respects: a. Missing signatures b. Requirement for internal approval from the Airline was not indicated c. Missing signature on the line change request was accomplished yet the grease was implemented. The management of the company could not explain how the change was implemented without the required signatures. The change to Aero shell 33 was not modified at the GMM, it still shows the use of Mobil grease 28, this indicates lack of procedures or failure to follow procedures. Failure to fill required senior positions-Similarly with the FAA report the safety board noted that the airline’s top management seats were vacant. The positions are director of maintenance, director of operations and director of safety. Although the director of maintenance position was shared between two people, duties and responsibilities were not clearly defined. Confusion of who is to do what tasks surfaced. In addition, the director of safety did not report directly to the highest level of management. The safety board noted there was lack of emphasis on maintenance and safety. Inadequate lubrication of jackscrew assemblies-Report indicated that 3 out of 34 MD 80 aircrafts, jack assemblies had excessive high wear rates. Lack of lubrication explains the high wear and tear in the jackscrew rather it was not the contamination, improper ACME thread surface finish or any other possible problem. At least one lubrication process ought to have been missed or inadequately performed on the investigated accident assembly. Inadequate or missed lubrication process results in an increased wear rate. This finding indicated poor training in this task or either poor supervision of maintenance personnel performing this task. Inadequate lubrication of rudder trim tab hinges support bearings- Regardless of how long the Alaska Airline had done a C check or scheduled lubrication, the condition of the rudder trim tab hinge bearings suggested that they were not adequately lubricated during the last scheduled lubrication opportunity. Lubrication practices conducted at the Alaska Airline brings out many concerns relating to lubrication of jackscrew assemblies. A poor maintenance practice was evident. Failure to process order for new jackscrew assembly-Due to the endplay measurement of jackscrew, a non-routine work card was generated to begin the process of ordering a replacement jackscrew assembly. However, the jackscrew was never ordered for and the accident plane was returned to service. The failure to order for the jackscrew was a clear indication of failure to comply with the internal procedures, thus poor maintenance control. After the NTSB came up with the above findings, they gave the following recommendations: Revision of lubrication procedures for the Boeing commercial Airplane group concerning lubrication procedures for the horizontal stabilizer trim system of Douglas DC-9, McDonnell Douglas MD-80/90 and Boeing 717 series airplanes to minimize the probability of inadequate lubrication (Pantankar and Taylor, 2004). Requirement for the Boeing Commercial Airplane Group to revise the end play check procedure for the horizontal stabilizer trim system of Douglas DC-9, McDonnell MD 80/90 to minimize the probability of measurement error. Require maintenance personnel to undergo specialized training for the task of lubrication of the horizontal stabilizer trim system of Douglas DC-9, McDonnell MD 80/90 to minimize the probability of measurement error. Require maintenance personnel who inspect the horizontal stabilizer trim of Douglas, McDonnell Douglas MD-80/90 to undergo specialized training in order to familiarize with using tools to perform the endplay check in terms of selecting and inspecting. Principal maintenance inspectors were issued with guidance to notify all operators about the potential hazards of using inappropriate grease types and mixing incompatible grease types. Operators of Douglas DC-9, McDonnell Douglas MD-80/90 and Boeing 717 series airplanes to remove degraded grease from the jackscrews assembly acme and flush degraded grease and particulates from the acme nut before applying fresh grease. This is part of the response safety recommendation. Safety recommendation A-01-41 which requires operators of Douglas DC-9, McDonnell Douglas MD-80/90 and Boeing 717 series airplanes, to increase the size of the access panels that are used to accomplish the jackscrew lubrication procedure. Establishing an inspectors’ sign off inspection item that have the jackscrew assembly lubrication procedures. Effects of the Federal Aviation regulations on the accident The FAA’s April 2000 special inspection unearthed many significant problems concerning the FAR’s that it should have identified earlier. It is of fact that these problems were only discovered when the accident of flight 261 had occurred. It means that the FAA failed in some way in checking the FAR’s of the Airline. It emerged that the surveillance of the Airline was inadequate for one year before the accident (Soucie and Cheek, 2011). The replacement of the Program Tracking and Reporting system (PTRS) of oversight at the Airline with the Air Transportation Oversight System (ATOS) in October 1998 led to reduced amount of time inspectors for actual surveillance activities. The Seattle Flight Standards District Office (FSDO) established the introduction of ATOS that has probably decreased the amount of surveillance. FAA indicated that the Seattle FSDO continued to operate with the existing inadequate number of airworthiness inspectors that led to less surveillance, which increased the chances of incidents or accidents at Alaska airlines. The NTSB concludes that the maintenance operations at Alaska Airlines were not fulfilled by the FAA concerning FAR’s. At the time of the accident, the FAA surveillance of Alaska Airline had been lacking for several years. FAA’s approval to Alaska Airline for extension of the lubrication interval of the jackscrew raised the possibility of inadequate lubrication that could cause excessive wear of the acme nut threads. It was a violation of FAR’s, that contributed to the accident. Another FAR that was violated by FAA that was a causal factor to the accident was the extension of end play check intervals. It increased the chances of excessive wear of the acme nut threads that enhanced failure of extension. FAR’s Recommendations that would prevent future accident In order for the company not to have similar accidents, in future Federal Aviation Administration came up with recommendations concerning Federal Aviation Regulations. According to Pantankar and Taylor (2004), before implementation of any changes in maintenance tasks intervals that may affect serious aircraft components technical data and analysis for every task showing that no change will present hazardous effects and get an official approval of the proposed changes from FAA aircraft certification office that deals with FAR’s. Federal Aviation Regulations should be revised and any related guidance be applied to the certification of transport aircrafts to make certain that wear related failures are totally considered and addressed such that to the maximum likely reason they will not be calamitous. Modify the certification of Federal Aviation Regulations, policies or procedures to ensure that there is no certification of new design of horizontal stabilizer trim if they have single calamitous failure method. FAA should carry out a systematic engineering review concerning the Federal Aviation Regulations. This is to eliminate the disastrous effects of total ACME nut thread failure in the horizontal stabilizer trim system jackscrew assembly in McDonnell MD 80/90. Oblige operators to measure and record the on wing endplay measurement every time a jackscrew assembly is done. Management issues that contributed to the accident After conducting a comprehensive investigation of the accident on Alaska Airline flight 261, many indications concerning the management were brought out. There was failure to fill the required senior management positions. For instance, the seat for Director of Maintenance had been vacant for two years (since 6/12/98) before the accident occurred. In addition, the seats of the director of operations and director of safety were vacant. It emerged that two people shared the duties and responsibilities of the Director of Maintenance. Furthermore, their duties were not clearly marked. This led to the confusion of who is to do what tasks. Moreover, the Director of safety was also acting as the Director of Quality Control and Training. He could not manage the duties and responsibilities of the two seats alone. This was a contributing factor for him not to reporting to the highest level of management. The board noted that Alaska Airline did not put much emphasis to matters concerning safety and maintenance. Conclusion After investigating the probable cause of the accident of Alaska Airline flight 261, it emerged that the plane lost pitch, control brought about by the failure of the horizontal stabilizer trim system jackscrew assembly’s acme nut threads. Thread failure was because of excessive wear that came from the Airlines’ insufficient lubrication of the jackscrew assembly. The Alaska Airline contributed to the accident for extending lubrication interval of the jackscrew. In addition, the FAA approval for that extension increased the likelihood of a missed or inadequate lubrication that caused excessive wear of the acme nut threads. Not forgetting, Alaska Airline also extended the endplay check interval in which also the FAA approved that extension which gave room to excessive wear of the acme nut threads that progressed to failure for detection. Another contributor to the accident was that McDonnell Douglas MD-80 did not have a fail-safe mechanism that can avoid the disastrous effects of total ACME nut thread loss. In conclusion, the above causes among others were the main factors that led to the accident of flight 261, Alaska Airline. References Annex 13 to the Convention on International Civil Aviation: Aircraft Accident and Incident Investigation, (November 2001). Custard, N.L. (2003). Crash of Alaska Airline flight 261. Carlisle Barracks, PA: U.S. Army War College. Krause, S.S. (2003). Aircraft safety investigations, analyses, and applications (2nd ed.). New York: McGraw-Hill. Loss of control and impact with Pacific Ocean, Alaska Airlines flight 261 McDonnell Douglas MD-83, N963AS about 2.7 miles north of Anacapa Island, California, January 31, 2000. (2002). Washington, D.C.: National Transportation Safety Board. Pantankar, M. S., & Taylor, J. C. (2004). Risk Management and Error Reduction in Aviation Maintenance, Aldershot, Hampshire: Ashgate. Soucie, D., & Cheek, O. (2011). Why Planes Crush: An Accident Investigator’s Fight for Safe Skies. New York: Skyhorse Pub.. Wood, R.H., Sweginnis, R.W., & Lederer, J. (2006). Aircraft accident investigation (2nd ed.). Casper, WY: Endeavor Books. Read More