British Midland Flight 92 from Heathrow to Belfast crashed near Kegworth, England in 1989, killing 47 people. A fan blade broke off on the left engine, causing vibration, but the pilot mistakenly shut down the right engine instead. The left engine then failed 20 minutes later, as the pilot had not detected the initial error. The crash resulted from a combination of factors including pilot error, inadequate training, aircraft design issues, and lack of communication between the pilot and cabin crew.

1. Kegworth Air Disaster
<Presentation>, 2008 Slide 1

2. The Kegworth Air Disaster
• 8th January 1989
• British Midland Flight 92
– Heathrow to Belfast
• Boeing 737-400
– New variant of Boeing 737
• Crashes by the M1 near
Kegworth, attempting an
emergency landing at East
Midlands Airport
• 118 passengers, 8 Crew
– 47 die, and 74 seriously injured
<Presentation>, 2008 Slide 2

3. The Kegworth Air Disaster
• The left engine was unable
to cope with the vibrations
caused when operating
under high power settings
above 25,000 feet.
• A fan blade broke
off, causing an increase in
vibration, reduction in
power, and there was a
large trail of flame behind
the engine.
• The pilot shut down the
engine on the right.
• The plane flew for another
20 minutes until the left
engine failed
<Presentation>, 2008 Slide 3

4. Right engine shutdown
• Mistake in knowledge based performance - Smoke in the
cabin indicates that the engine from which bleed air (used
for heating, pressure, etc) is taken will have smoke in it.
But, the pilot thought bleed air was taken from the right
engine. This is true of the Boeing 737 but not the new
737-400, which drew bleed air from both.
• Design issue - No visibility of engines, so relied on other
information sources to explain vibrations
• Design issue – The vibration sensors were tiny, had a new
digital display style and were inaccurate on the 737 (not
the 737-400)
• Inadequate training - A one day course, and no simulator
training
<Presentation>, 2008 Slide 4

5. Failure to detect error
• Coincidence – The smoke disappeared after shutting down
the right engine and the vibrations lessened. “Confirmation
bias”.
• Lapse in procedure – After shutting down the right engine the
pilot began checking all meters and reviewing decisions but
stopped after being interrupted by a transmission from the
airport asking him to descend to 12,000 ft.
• Lack of Communication - The cabin crew and passengers
could see the left engine was on fire, but did not inform the
pilot, even when the pilot announced he was shutting down
the right engine.
• Design Issue – The vibration meters would have shown a
problem with the left engine, but were too difficult to read.
There was no alarm.
<Presentation>, 2008 Slide 5

6. Cockpit of a Boeing 737
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7. Cockpit of a Boeing 737-400
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8. Cockpit of a Boeing 737-400
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9. Conclusion
• Pilot error?
• Crew training?
• User interface design?
• Aircraft design?
• Engineering problems?
• Lack of proper training?
<Presentation>, 2008 Slide 9

10. Failures are rarely ever simple!
The problem is complexity
<Presentation>, 2008 Slide 10