Kegworth 1989: an accident occurs?
The January 8, 1989 was a routine domestic flight 092 en route from London Heathrow to Belfast in Northern Ireland. It 'was the second flight of the British Midland Boeing 737-400, the day and the plane landed near his goal was when a combination of human error and mechanical carried out for a disaster.
Led Tail Light
Preparing for the East Midlands airport to land the aircraft (tail marked G-OBME) brokeon an embankment of the M1 motorway near Kegworth, Leicestershire, killing 47 people and injuring 74 others, including seven crew members.
In summary of the causes of the accident, the report says plane crash, "The cause of the accident was that the operations team, the No. 2 engine had broken down after a fan blade in the engine No. 1. This engine subsequently suffered a significant loss of thrust due to the fan secondary damage after power had been growingin the final for landing '(AAIB 1980, 35). One thing is certainly true, but it was a combination of errors, mechanical, procedural and cognitive skills, which eventually caused the failure of the aircraft during the final landing .
Extrapolating the events of that day, it is necessary to examine a chain of events, instead of studying each component failure or sequentially. As often happens in plane crash investigation of a series of human resources and operationalError tends to be a domino effect in which the inertia of an event to another, resulting in a catastrophic outcome (work, 1996, 173) for the production. The chronology of these events is therefore particularly important to analyze the chain of failure that led to the crash.
G-OBME was performed on a busy dual-shuttle from the airport to London Heathrow and Belfast Aldergrove Airport. The first leg of the trip was quiet. During the second phase of the shuttleFirst plane climbed to 6,000 feet, where it stabilized for about two minutes to go before receiving authorization to an altitude of 12,000 feet. At 07.58 the clock, was given space to climb to 35,000 feet. At 8.05 the clock, when the plane was climbing through flight level 283, the team of strong vibrations and a smell of fire experience. No alarm fire were alerted by visual or acoustic instruments on the flight deck. A repetition of the next flight recorderExperience has shown that in severe shock No 1 (left) is the driving test, along with notes on an irregular fan speed, an increase of discharge temperature and low fuel flow variable (OIE, 1980, 145).
Captain Hunt took control of the aircraft and the autopilot off. He said that the engine instruments, no clear reference to the source of the disturbance. He explained that he thought the smoke was satisfied with the passenger cabinwhich is its understanding of the 737 air-conditioned, led him to believe that smoking, in fact, from No. 2 (right) engine was. Consequently, the command was given to reduce the engine No. 2. As a result of this procedure, the aircraft slowly rolled to the left to sixteen degrees, but no corrective movements of the rudder or ailerons a commander.
The captain later claimed that the reduction of the engine throttle valve reduces the smell and the No. 2And signs of smoke, but then recalled that the significant vibration was closed after the No. 2 throttle further.
After throttling the No. 2 engine, London air traffic control were alerted immediately of an emergency with a fire engine appeared. Forty-three seconds after the start of vibration of the First Officer McClelland ordered the commander to "switch off". This arrest was delayed to the first officer responded to radio messages from the London Air TrafficPanel to ask what they wanted alternative airport to the ground. Shortly after the close of the No. 2 engine aircraft, the BMA called for operations in East Midlands Airport (OIE, 1980, 40) to distract.
Once the engine No. 2 was closed, all showed signs of smoke from the cockpit, the more convinced the commander that the right decision to make, not least the engine No.1 vacated no sign of a malfunction and has continued to operate at reduced power even if andincrease the fuel flow.
The passengers were aware of smoke and the smell as similar to "oil" or "rubber" in the cabin. Some passengers were able to see evidence of fire from the left engine fire and flight attendants than the No.1 engine light and smoke in the cabin.
Despite signs that the fire goes out from the other engine, cabin crew or alerted passengers or the crew of that fact. That may have adhered to due to the general confusion at the time,with the belief that the pilot ultimately did what he did.
At 08.20 the clock has been raised to a height of 3000 meters on the engine power No.1. The aircraft was then cleared two thousand feet deep, and urged the membership to the center line at 2,000 meters above ground level (AGL), the commander of the landing gear down and flaps are used on fifteen degrees. At 900 meters there was a sudden decrease of power from the engine No. 1. While theAir drops below the glide slope and the proximity of the alarm system on the ground (GPWS) sounded the Commander-show "to prepare for crash landing" on the cabin speaker system. The aircraft on the ground to 20.24 with a clock speed of 115 knots.
One survivor, Gareth Jones, has described the moment when the plane on the ground as follows: "There was a shudder, crash, car accident as a massive engine, crunchy, black, and I was on the door emergency. " (BBC, 1989).
The report of the OIE (OIE,1980, 35) focused on the failure of its crew to react to a malfunction of the engine number one, and raised the following operational errors:
1 The combination of engine vibration, noise and smell of a fire outside their training and experience.
2 responded to the first engine problem early and in a way that was contrary to their training.
3 They have not assimilated the information on the display screen of the motor beforethrottled back the No. 2 engine.
4 Since the engine number 2 has been throttled back, heard the noise and excitement associated with the waves of the No. 1 motor, are convinced that they correctly identified the defective motor.
5 There were flames emanating from the engine No. 1 had and observed by many on board, including three flight attendants informed in the aft cabin.
The most accident reports cite human error as the main cause (Johnson, 1998).
But before you decide to be the obvious failure of disability Captain Hunt, of which 737 engines were not, however, their attention should be drawn on the same defective motor. The real cause of the malfunction was a broken turbine, causing the result of material fatigue caused by excessive vibration.
The new version of the CFM56 engine used on the 737-400 model, were excessive vibration when operating at higher power settings to 25,000Feet. Since this is an upgrade of an existing machine, the engine still had only been tested in the laboratory, not in real flight conditions. When this fact was discovered about a hundred years 737-400 were then ground and subsequently modified engines. Since the incident Kegworth all turbofan engines significantly revised must be tested in real flight conditions. Well, so do not adequately tested the CFM56 engine on Flight 092 is already "an accident waiting"Happen (Owen, D. 2001, 132).
The OIE report concluded that the combination of engine vibration, noise and the smell of fire outside the cabin crew compartment. (OIE, 1980). This may or may not be a fair assessment, since only a few pilot and first officer, thankfully never experience the true impact of smoke and fire, while the command is.
While simulators to help train for emergency response, one might wonder how important this process could be, especially ifthe crew were not the procedural requirements and technical specifications in a variant of aircraft in flight training. Significantly, the crew of 092 had little confidence in the correctness of the instrument panel key with a vibration meter.
Dr Denis Besnard at Newcastle University looked at the Kegworth air crash, the conclusion of "The pilots of the B737 in what tend to confirm prejudices, where instead of looking for evidence to the contrary were people known prisoneroverestimate consistent data. Ignore the people, and sometimes unconsciously disregard data do not explain "(Besnard D, 2004, 117) is possible.
"Confirmation bias", ie the overhead of consciousness through a lot of uncertain or conflicting data was also used as the main cause of the crash when they are examined by a team of researchers at the University of York and the University of Newcastle upon Tyne . The argument that people over simplify complex situations, especially during the ruleCrisis has been both well documented and significant in the case of the Kegworth air crash (Besnard. D., Greathead, G. & Baxter, G, 2004, 117-119).
More specifically, Captain Hunt had no training on the new model 737-400, as there are no simulators for this variant will receive in Britain at this time. This is both surprising and important, considering the following points. The captain believed that the right engine was the smell of smoke of a malfunction, perhaps becauseFirst Boeing 737 models of air for the air conditioner was taken from the right engine.
However, starting with a new variant of the Boeing 737-400 Boeing bleed the system using both engines. Captain Hunt was unaware of this fact, which formed an important part of its decision to shut the engine wrong. This would be disastrous.
In addition to the compliance of smoke-gas disappears when the car was issued to pilotshad a habit, without considering the readings of the vibration, the beginning of those who were perceived as unreliable. The crew of G-OBME seem unaware that they were newer, but more reliable to have. More attention should have been paid, so the problems of vibration rather than the smell of smoke and fire can also be very different events on the evening of January 8 (; 131-2 Owen, 2001) have been leaked.
Subsequent studies have determined critical"Error creating the organizational conditions necessary for human error" and "organizational failure also aggravate the consequences of failure" (Stanton, 1994, 63). The Kegworth air crash was therefore the result of a series of errors by a mechanical defect.
In addition, greater cognitive errors by the crew due to insufficient flight training improved the chain of errors. Finally, the crew did not check their interpretation of eventsConsultation with the cabin crew or passengers, even if the information was interpreted by the error with the other engine of the aircraft at the time.
Bibliography
BBC (1989) of the Day: Dozens die in plane crashes highway. [Online] available http://news.bbc.co.uk/onthisday/hi/dates/stories/january/8 [Accessed 2 March 2007]
Besnard, D. (2005) and the International Aviation Fire Protection Association. [Online] Availablehttp://www.iafpa.org.uk/news-template.php?t=4&id=1312 [accessed March 1, 2007]
Besnard, D. Greathead, G., and Baxter, G. (2004) International Journal of Human-Computer Studies. When mental models go wrong. Co-occurrences in dynamic, critical systems, vol. 60, p. 117-128.
Job, M. (1996) Air Disaster Volume 2 p. 173-185. Aerospace Publications Pty. Ltd.
Johnson, D. 1988, University of Glasgow Department of Computing Science (1980) Viewing the relationship betweenHuman error and organizational psychology [online] University of Glasgow, 1980. http://www.dcs.gla.ac.uk/ ~ johnson / papers / fault_trees / organisational_error.html [accessed 2 March 2007]
Owen, D. (2001) Air Accident Investigation, Ed 1, Chapter 9, p. 132-152. Sparkford, Patrick Stephens Ltd
Stanton, NA (1994) the human factors of alarm design, Ch 5, p. 63-92. London, Taylor and Francis Ltd
UNITED KINGDOM. Air Accidents Investigation Branch (1990) Boeing 737-400, G-OBME nearKegworth, Leicestershire January 8, 1989, number 4 / 90 London, HMSO.
Kegworth Air Crash Investigation