Japan Airlines Flight 123 Crush - Essay Example

Case Study Analysis Activity Japan Airlines Flight 123 Cause(s) of Accident The aircraft accident involving Japan Airlines Flight 123 occurred on August 12, 1985. This accident is the world’s worst aircraft accident involving a single airliner. The aircraft experienced mechanical failures after 12 minutes of flight and crashed 32 minutes later killing 505 out of 509 passengers and all the fifteen-crew members (Miller et al., 2010). There are probable causes that are attributed to the accident. According to a report published by Japan’s Aircraft Accidents Investigation Commission, the accident was as a result of an incorrect repair procedure following a tailstrike that the aircraft had suffered in 1978 (Aviation Safety Network, 2012). The incorrect procedure led to explosive decompression and bulkhead breaking that ruptured hydraulic system of the whole aircraft thereby rendering the airplane uncontrollable. Because of an improperly repaired rear pressure bulkhead by Boeing, the aircraft lost the flying surfaces in the tail, as well as the control surfaces to a considerable extent on the wings (Federal Aviation Administration, 2012). Structural and Mechanical Factors The investigations into the accident by the Aircraft Accident Investigation Commission pointed out to the fact that the accident was largely as a result of structural and mechanical factors. As has been mentioned, Japan Airlines Flight 123 had been involved in a tailstrike incident in 1978 at Osaka International Airport, and the accident damaged its rear pressure bulkhead (Miller et al., 2010). While proper repairing of this mechanical problem would have effectively averted the possibility of accident caused by this problem, this seems not to have happened as it seems subsequent repair was improper and did not conform to approved repair methods recommended by Boeing (International Aviation Safety Association, 2005). The Boeing technicians who fixed the aircraft used two different doubler plates, one with only one row and one with two rows of rivets. This is against the approved procedure, which calls for one continuous doubler with three rivets rows in order to reinforce the bulkhead that has been damaged. The procedure applied by the technician reduced the bulkhead’s resistance to metal fatigue by about 70 percent (Hood, 2011). The investigation also revealed that Boeing had calculated that the improper installation would fail after nearly 10,000 pressurizations. From the time when the faulty repair was made and the time when the crash occurred, the aircraft had accomplished exactly 12,318 successful flights. This accomplishment was well beyond the approximated pressurizations and the accident was simply inevitable (Aviation Safety Network, 2012). The accident was because of fatigue-induced structural failure that led to the substantial damage of aircraft’s tail assembly that caused its separation from the aircraft. Shortly after the decompression, the aircraft was struck by total hydraulic failure that disabled all the three flight control surfaces. As a result, the aircraft became unstable because of stabilizer loss, a situation that made the crew unable to control the whole flight – they were only able to control the engine power (Federal Aviation Administration, 2012). It is the realization that the aircraft accident was caused by the aircraft’s loss of much of its vertical fin that made the investigators to conclude that the accident was because of rupturing of rear pressure bulkhead, which consequently blew off the tail assembly and severed the hydraulic lines (Miller et al., 2010). Contributing Factors It is no doubt that mechanical and structural factors are the main cause of the accident. However, there are contributing factors that in one way or another led to the accident. Complacence on the part of the airline and Boeing significantly contributed to the accident (International Aviation Safety Association, 2005). Following the tailstrike incident that the aircraft was involved in at Osaka International Airport, it was expected that Boeing and the airline take comprehensive measures towards ensuring that subsequent repair of the bulkhead is done properly (Kilroy, 2012). Investigations revealed that Boeing technicians did not repair the bulkhead in accordance to the approved repair methods. As a result, the bulkhead’s resistance to metal fatigue was only reduced by some 70 percent and this meant that the safety of the aircraft was significantly compromised (Federal Aviation Administration, 2012). In addition, failure by the Japan Airlines and Boeing to ensure the highest levels of safety and maintenance contributed to the accident. The improper installation was calculated to have failed after about 10,000 pressurizations. However, the aircraft accomplished 12,318 successful flights between the time it was repaired and the time that the crash occurred (Hood, 2011). This points out to negligence on the part of the airline and Boeing towards ensuring safety and high maintenance of the aircraft. Proper maintenance and safety inspection would have identified the problem in the bulkhead and therefore the accident would have been prevented (Aviation Safety Network, 2012). Investigation Board Findings Japan’s Aircraft Accidents Investigation Commission investigated into this accident, which is the worst single-aircraft accident ever. The Commission made a number of findings. The first one is the fact that the aircraft that was involved in this accident had been involved in an airstrike incident on 2 June 1978 at Osaka International Airport, and as a result, it damaged its rear pressure bulkhead (Kilroy, 2012). Secondly, it found that the subsequent bulkhead’s repair was not done in accordance to approved repair methods that have been recommended by Boeing (Miller et al., 2010). Thirdly, the commission found out that the aircraft was flying beyond the approximated flights that had been approximated after the improper repair. It also found out that the accident was mainly because of the inappropriately repaired rear pressure bulkhead which led to explosive decompression and breaking of bulkhead that ruptured all the hydraulic system of the aircraft rendering it uncontrollable (Hood, 2011). Recommendations Several recommendations were made after the conclusion of the investigation of Japan Airlines Flight 123 accident. The first one is the recommendation that requires the manufacturer to make modifications to the design of Boeing 747 empennage so that the structural integrity of the stabilizers and their control surfaces will be protected in the event that considerable pressure builds up happens (Hood, 2011). The second recommendation was that require the manufacturer to modify Boeing 747 hydraulic systems design so that the integrity of all hydraulic systems cannot be impaired incase a significant buildup happens in the unpressurized empennage (Federal Aviation Administration, 2012). The other recommendation was on the need for evaluation of all procedures of repairing Boeing 767 and Boeing 747 bulkheads to ensure that the “fail-safe” concept of the bulkhead design is not affected during the repair (Aviation Safety Network, 2012). Additionally, it was recommended that the inspection program for Boeing 747 be repaired in order to establish the interval of inspection beyond the routine visual inspection in order to detect the extent of possible fatigue cracking (Miller et al, 2010).. Outcomes The first outcome of this accident and subsequent recommendation was that there was amendment to regulatory policy to address the impacts of bomb explosions and rapid depressurizations (Hood, 2011). Moreover as a result of this accident, certain parts of the Code of Federal Regulations were modified to require that repair assessment programs be done in order to operate airplanes with pressurized fuselages beyond particular specified times of life cycle implementation (Aviation Safety Network, 2012). The recommendations of the investigation board were followed. This is demonstrated highly by in-service maintenance programs designed properly in Japan and across the world (Kilroy, 2012). In addition, reduced number of accidents from similar cause as of Japan Airlines Flight is a testimony that the recommendations were followed (Miller et al, 2010). References Aviation Safety Network. (2012). Accident Description: Japan Airlines Flight 123. Retrieved on 12 September 2012 from http://aviation-safety.net/database/record.php?id=19850812-1 Federal Aviation Administration. (2012). Japan Airlines 747 at Gunma Prefecture. Retrieved on 12 September, 2012 from http://accidents-ll.faa.gov/ll_main.cfm?TabID=2&LLID=16&LLTypeID=2 Hood, P. (2011). Dealing with Disaster in Japan: Responses to the Flight JL123 Crash. Routledge. International Aviation Safety Association. (2005). Japan Marks 20th Anniversary of JAL Crash. Retrieved on 12 September 2012 from http://www.iasa.com.au/folders/Safety_Issues/others/jal123.html Kilroy, C. (2012). Special Report: JAL Flight 123. Retrieved on 12 September 12, 2012 from http://www.airdisaster.com/special/special-jal123.shtml Miller, F et al. (2010). Japan Airlines Flight 123. VDM Verlag. Read More