The Kegworth Air Disaster - Research Paper Example

The Kegworth Air Disaster (British Midland Flight 92) Introduction This paper highlights the events that related to the Kegworth air tragedy on 8th January, 1989, when a British Midland Flight 92, Boeing 737 – 400, G-OBME crashed onto the embankment of the M1 motorway, short of the runway of East Midlands Airport, Leicestershire, next to the village of Kegworth, (ICON Group International, 2008). From the report given by Air Accidents Investigation Branch (AAIB) in London, (1990), the aircraft had 8 crew and 118 passengers on board. Out of this number, 47 died while the rest sustained serious injuries. Beyond this description, this paper examines some of the facts that might have contributed to the crash. It also identifies in detail the root cause of the accident as disclosed in various reliable sources including the report by AAIB that was given the following year after the crash. A range of human errors that might have contributed to the tragic accident are also disclosed. From the events surrounding the accident, it is good to borrow a leaf and learn to take necessary precautions to avoid such occurrences and also learn to take control of emergency situations. Description of the incident According to a 1999 BBC News report, the British Midland Flight 92, Boeing 737 – 400, G-OBME was scheduled to fly from London Heathrow Airport to Belfast Northern Ireland. It took off from Heathrow at 7:52 p.m. When the plane started climbing through 28300 ft, one of the fan blades on the left (No. 1) engine suddenly detached. This resulted into pounding noise with severe vibrations and smoke which poured into the cabin through the ventilation system sending the smell of burning. According to Books LLC. (2010), the pilots did not investigate the source of the problem. Having believed that it was the No. 2 (right engine) engine that had damaged, they decided to shut it down. The smoke disappeared soon after the No. 2 engine was throttled back while the No. 1 engine apparently operated normally. This gave the pilots the impression that they had taken the right step and felt that they had saved the aircraft from emergency. The pilots diverted the plane towards East Midlands Airport following instructions from British Midland Airways Operations. They controlled the plane to land on runway 27. For a little while, the aircraft seemed to respond normally though with high level of vibrations from the No. 1 engine. This followed an abrupt reduction of power and fire warning on the No. 1 engine. At the moment, the aircraft was flying at only 185km/h. The pilots tried to restart the No. 2 engine but it failed. By then, the plane was about 475m from M1 motorway and it crashed at this point. According to the AAIB Report (1990, p. 7), “the plane initially struck a field adjacent to the eastern embankment of the M1 motorway and then suffered a second severe impact on the sloping western embankment of the motorway.” Meanwhile, the airport's firefighters had already rushed to the scene and managed to put off flames coming from the No. 1 engine that sparked a major blaze. The plane had 126 people on board; 39 of the passengers died instantly from the incident while another eight died later. 67 passengers and seven members of crew staff sustained severe injuries. One crew staff and four passengers sustained minor injuries. Some Facts about the crash As indicated in the AAIB Report (1990), several factors contributed to the incorrect response of flight crew to the emergency. First, the heavy engine vibrations, mixed with a lot of noise and the burning smell were beyond the cabin crews’ training and experience. As noted on p. 108 of the report, “Smoke in the cabin indicates that the engine from which breed air that is used for pressure is taken will have smoke on it”, but the captain, Kevin Hunt, thought that the problem was with the right engine. When Hunt asked first officer, David McClelland which engine was malfunctioning, McClelland replied: 'It's the left … No, the right one.’ (p. 14). The captain then ordered the first officer to shut it down. Their reaction was a clear indication that the pilots had limited training on how to deal with such emergencies. The 737-400 model was an upgrade of older 737 versions and had only been flown for 520 hours over two months period (Books LLC, 2010). This model with upgraded engine had not been tested in the air, most of the tests having been done in the laboratory. There was also limited training of cabin crew on operations of this new version. For example, in the older version of 737, the air conditioning ran through the right engine, but on the 737-400 it ran through both, which the pilots were not used to. Another crucial issue was the design of the plane. There was no visibility of engines for this plane, which meant that the pilots had to rely on other information sources to explain vibrations. In addition, the plane’s vibration sensors which had a new digital display style were tiny and inaccurate, making them difficult to read. Apart form these facts, the plane had no alarm (AAIB Report, 1990).Though this was not a good excuse, the interruptions by transmission from the airport asking the pilot to descend to 12,000 ft, made the pilot to stop checking of meters and reviewing the source of the problem to control the plane. According to AAIB Report (1990) and Rooksby (2010), it was evident that these and other facts played a big role in the occurrence of the accident. The fundamental cause of the mishap Investigations were later carried out by AAIB about the incident (AAIB Report, 1990). From this report, it was noted that the CFM56 engines used on the 737-400 plane indicated that the LP Stage 1 compressor fan blades were subject to severe vibrations when operating at high power settings, above 900 ft above sea level. Further examinations of the wreckage showed that at such high settings, the rear of the engine was bound to increase vibrations due to the reduction in pressure. This was found to be the cause of increased vibrations of the No. 1 engine, leading to too much fatigue in its fan blades and on the G-OBME. Consequently, one of its blades broke off. The result was a complete damage of the engine No. 1, which initiated loss of balance of the plane. According to AAIB report (1990), it was coincidental that when pilots shut down the right engine, the symptoms of damage disappeared. It was also found out that when auto throttle was disengaged so as to shut down the right engine, the fuel flow to the No. 1 engine was reduced, leading to a reduction of the of the fuel that had been igniting in the jet exhaust. This led to reduction of damage, hence reduction of smoke and vibrations. Having diverted towards East Midland Airport, the speed of the aircraft slowly reduced to185 km/h. The auto throttle had tried to recover the problem by increasing fuel flow to the No. 1 engine, but the engine was damaged and could not be able to burn all the additional fuel (White, 1993). Much of the fuel was igniting in the exhaust flow, making it burst into flames behind the engine. Attempts by pilots to restart the right engine by use of air flowing through it in order to rotate the turbine blades to start it proved futile. Investigations by AAIB found out that after shutting down the No. 2 engine, the outer panel of one fan blade had detached and became lodged in the space between the fan and fan outlet guide vanes. The damage was almost similar to the one on the No. 1 engine (AAIB Report, 1990). Thus, the engine could not restart and in no time, the plane hit the ground, just before reaching the M1 Motorway. Violations by fight crew The Boeing 737 – 400, G-OBME took off successfully and climbed through 28300 ft, after which symptoms of a faulty engine were noticed. Apparently, pounding noise, severe vibrations and smoke were all evident to the pilots, but they were not aware of the fire sparks. Some passengers and three members of the crew had witnessed fire sparks which was a clear sign of burning. One of the crew staff in the cabin responded by approaching the pilots to give them the whole information. Just before delivering the message, the captain assured the crew staff that there had been a malfunction with one of the engines and that they already had succeeded in containing it. This gave an impression to the crew staff that the pilots were aware of the whole problem and went back to the cabin to return the message. The pilots had already responded by shutting down the right engine which was not faulty. This instance indicated poor coordination between the flight deck and crew staff (Inc Icon group international, 2008). From crew assessment by AAIB, the pilots had not assimilated the source of problem from the engine instruments before taking actions. The tests that were done later on engine parameter variation instrument proved that it was in proper condition and there was no evidence to show that it did not give display before the crash. When AAIB inquired from the first officer about what the engine display instruments indicated, he was unable to recall. Just before the crash, he was asked by the captain which engine was faulty, but he hesitated and said it was the left, before saying the right. This brought to light the fact that the officer did not take time to understand indications from display instruments or this could have come about due to genuine difficulty in interpreting the readings on the instruments (AAIB Report, 1990). The captain ordered the officer to shut down the faulty engine even without specifying which one. The officer proceeded to throttle back the right engine. The captain proceeded to justify his actions by stating that the engine instruments were not clear where the trouble was coming from. He also said that he judged the No. 2 engine to be faulty from his prior knowledge of plane’s air conditioning system. His argument was not supported by the evidence that was available since there had been smoke fumes in the cockpit which evidently came from the left engine. He had also failed to confirm from the flight service manager whether there was smoke in the passenger cabin. He instead believed in the first officer’s assessment and never took time to confirm it (AAIB Report, 1990). The pilots’ actions were contrary to their training instructions and also to their operations manual. If they had taken more time to understand the engine display instruments, they could have learnt the fact that it was the left engine which had been having problems and not the right one. Though the captain disengaged the autopilot, this should not have prevented him from taking time to assimilate readings for both engine instruments from the display instruments. The rapid reaction of the pilots before compiling positive evidence concerning the faulty engine constituted failure on their part. Damages As indicated earlier, this tragic accident claimed the lives of many people, leaving many others with physical and/or psychological injuries. In a village cemetery near Kegworth, a memorial was constructed of those who died, those who were injured and also those that were involved in rescue operations (Books LLC, 2010). Though the captain, Kevin Hunt and the first officer, David McClelland sustained injuries, they were dismissed by AAIB Report after it was found out that their actions had contributed to the crash (AAIB report, 1990). Thus, they could not be compensated. Some victims and also those who witnessed and were involved in rescue operations later received compensation for damages (Books LLC, 2010). Conclusion With time, technical development has produced more complex aircraft systems and thus the crew cannot be expected to internalize in depth the technical knowledge of all the new systems. However, with these advancements there has been production of systems which are more reliable. Due to this technical progress, continuous training of pilots and cabin crew is recommended so as to learn new principles that are introduced. . It is also advisable for the flight crew to learn to deal with emergencies procedurally. This means that the crews need to evaluate emergency situations before making any decisions. The findings of the Boeing 737 – 400, G-OBME tragic accident raise questions concerning the level of technical knowledge that the pilots and the cabin crew had. They failed to assimilate the readings of engine instruments and poor communication amongst them was evident as the disaster took it toll. References Air Accidents Investigation Branch (AAIB) (1990 January 25) Report on the accident to Boeing 737-400, G-OBME, near Kegworth, Leicestershire on 8 January 1989 (Report No: 4/1990) 2/90, 1-161. London: Department of Transport Print. BBC News Report (Friday, January 8 1999). “Air crash hero wins damages.” Retrieved 7 February, 2011 from http://news.bbc.co.uk/1/hi/uk/54915.stm. Books LLC, (2010). 1989 in Northern Ireland: Kegworth Air Disaster. California: General Books LLC Print. Inc Icon Group International (2008). Runways: Webster's Quotations, Facts and Phrases. London: Icon Group International Print. Rooksby, J. (2010) “The Kegworth Air Disaster,” Human Error Web. Retrieved 6 February 2011, from http://www.cs.st-andrews.ac.uk/~ifs/Teaching/.../L5-HumanError-Handout. White, D.B. (Ed.) (1993) “The effects of brace position on injuries,” Aviation, space and environmental medicine Web. Retrieved 7 February 2011, from http//www.snopes.com/travel/airline/brace asp. Read More