Kegworth 1989: an accident waiting to happen?
On January 8, 1989, routine domestic flight 092 was enroute from London Heathrow airport to Belfast in Northern Ireland. It was the second flight undertaken by the British Midland Boeing 737-400 that day and the aircraft was close to its landing destination when a combination of mechanical and human error led to disaster.
Preparing to land at the East Midlands airport, the aircraft (tail marked G-OBME) plummeted onto an embankment of the M1 motorway near Kegworth, Leicestershire, killing 47 people and seriously injuring a further 74, including seven members of the flight crew.
In summarising the cause of the accident, The Aircraft Accident Report stated "The cause of the accident was that the operating crew shut down the No.2 engine after a fan blade had fractured in the No.1 engine. This engine subsequently suffered a major thrust loss due to secondary fan damage after power had been increasing during the final approach to land" (AAIB 1980, 35). This much is certainly true, however it was a combination of errors, mechanical, procedural and cognitive, which ultimately caused the aircraft to fail during its final landing phase.
In order to extrapolate the events of that day it is necessary to examine a chain of events rather than to study each constituent error or malfunction in turn. As is often the case with aircraft crash investigation, a sequence of human and operational errors tends to produce a domino effect in which it is the inertia of one event beyond another that results in a catastrophic conclusion (Job,1996; 173). The chronology of these events is therefore particularly important in helping to analyse the failure chain that led up to the crash.
G-OBME was engaged on a double shuttle run between London Heathrow airport and Belfast Aldergrove Airport. The first leg of the journey was uneventful. During the second leg of the shuttle the aircraft climbed initially to six thousand feet where it levelled-off for about two minutes before receiving clearance to climb to a flight level of twelve thousand feet. At 7.58 p.m., clearance was given to climb to thirty five thousand feet. At 8.05 p.m. as the aircraft was climbing through flight level 283 the crew experienced severe vibration and a smell of fire. No fire warnings, visual or audible were alerted by instruments on the flight deck. A later replay of the Flight Data Recorder showed that severe vibrations had occurred in the No.1 (left) engine, together with indications of an erratic fan speed, a rise in exhaust temperature and a low, variable fuel flow (AAIB, 1980; 145).
Captain Hunt took control of the aeroplane and disengaged the autopilot. He later claimed that the engine instrumentation did not give him any clear indication of the source of the malfunction. He also later stated that he thought that the smoke was coming forward from the passenger cabin which, from his understanding of the 737's air conditioning system, led him to believe that the smoke was in fact coming from the No 2 (right) engine. Consequently the command was issued to throttle back the No.2 engine. As a result of this procedure the aircraft rolled slowly to the left through sixteen degrees but the commander made no corrective movements of either rudder or aileron.
The commander later claimed that reducing the throttle of No.2 engine reduced the smell and signs of smoke and but he later remembered that the significant vibration continued after the No.2 throttle was closed.
After throttling back the No.2 engine, London Air Traffic Control were immediately advised of an emergency situation with appeared to be an engine fire. Forty-three seconds after the onset of the vibration the commander ordered First Officer McClelland to "shut it down". The shut down was delayed at the First Officer responded to radio messages from London Air Traffic Control asking which alternative airport they wished to land at. Shortly after shutting down No.2 engine BMA Operations requested the aircraft divert to the East Midland Airport (AAIB,1980; 40).
Malaysian investigators 'puzzled' by missing plane by itnnews
Article Source: http://EzineArticles.com/1024617
On January 8, 1989, routine domestic flight 092 was enroute from London Heathrow airport to Belfast in Northern Ireland. It was the second flight undertaken by the British Midland Boeing 737-400 that day and the aircraft was close to its landing destination when a combination of mechanical and human error led to disaster.
Preparing to land at the East Midlands airport, the aircraft (tail marked G-OBME) plummeted onto an embankment of the M1 motorway near Kegworth, Leicestershire, killing 47 people and seriously injuring a further 74, including seven members of the flight crew.
In summarising the cause of the accident, The Aircraft Accident Report stated "The cause of the accident was that the operating crew shut down the No.2 engine after a fan blade had fractured in the No.1 engine. This engine subsequently suffered a major thrust loss due to secondary fan damage after power had been increasing during the final approach to land" (AAIB 1980, 35). This much is certainly true, however it was a combination of errors, mechanical, procedural and cognitive, which ultimately caused the aircraft to fail during its final landing phase.
In order to extrapolate the events of that day it is necessary to examine a chain of events rather than to study each constituent error or malfunction in turn. As is often the case with aircraft crash investigation, a sequence of human and operational errors tends to produce a domino effect in which it is the inertia of one event beyond another that results in a catastrophic conclusion (Job,1996; 173). The chronology of these events is therefore particularly important in helping to analyse the failure chain that led up to the crash.
G-OBME was engaged on a double shuttle run between London Heathrow airport and Belfast Aldergrove Airport. The first leg of the journey was uneventful. During the second leg of the shuttle the aircraft climbed initially to six thousand feet where it levelled-off for about two minutes before receiving clearance to climb to a flight level of twelve thousand feet. At 7.58 p.m., clearance was given to climb to thirty five thousand feet. At 8.05 p.m. as the aircraft was climbing through flight level 283 the crew experienced severe vibration and a smell of fire. No fire warnings, visual or audible were alerted by instruments on the flight deck. A later replay of the Flight Data Recorder showed that severe vibrations had occurred in the No.1 (left) engine, together with indications of an erratic fan speed, a rise in exhaust temperature and a low, variable fuel flow (AAIB, 1980; 145).
Captain Hunt took control of the aeroplane and disengaged the autopilot. He later claimed that the engine instrumentation did not give him any clear indication of the source of the malfunction. He also later stated that he thought that the smoke was coming forward from the passenger cabin which, from his understanding of the 737's air conditioning system, led him to believe that the smoke was in fact coming from the No 2 (right) engine. Consequently the command was issued to throttle back the No.2 engine. As a result of this procedure the aircraft rolled slowly to the left through sixteen degrees but the commander made no corrective movements of either rudder or aileron.
The commander later claimed that reducing the throttle of No.2 engine reduced the smell and signs of smoke and but he later remembered that the significant vibration continued after the No.2 throttle was closed.
After throttling back the No.2 engine, London Air Traffic Control were immediately advised of an emergency situation with appeared to be an engine fire. Forty-three seconds after the onset of the vibration the commander ordered First Officer McClelland to "shut it down". The shut down was delayed at the First Officer responded to radio messages from London Air Traffic Control asking which alternative airport they wished to land at. Shortly after shutting down No.2 engine BMA Operations requested the aircraft divert to the East Midland Airport (AAIB,1980; 40).
Malaysian investigators 'puzzled' by missing plane by itnnews
Article Source: http://EzineArticles.com/1024617
