Kegworth Air disaster

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Kegworth Air disaster

• Example of multiple levels of analysis
• What causes a plane to crash? 1 min.

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What causes a plane to crash?

• A laundry list is required, or, a swiss cheese
  loaf lined up
• A lot, in safety critical systems

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Kegworth Air Disaster

• Why?
• Near Ritter, Baxter Churchill
• A lovely example
• Often used

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Storyline

• Flight, jan 1989, Heathrow to Belfast, Midland
  192
• Experienced pilots, new plane (737)
• Part of one of the safest systems in the world
• Upon take-off, no problems
• Shuddering, fire in an engine at 10 min.
• Shut off 2 engine, RHS (the good one!)
• This is the pilot error

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Hardware and Mischance

• ?badly designed new engine, failure at 3 months,
  approx. t300 h, should be t500,000 h, not
  tested at altitude
• ?/?unlucky choice of diversion airport BMI hub

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Auto throttle problem

• ?poor mental model of plane system(turned off
  good engine, which disengaged autothrottled,
  solving the judder problem)
• ?lack of engine feedback interface design

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Vibration Dial 1

• ?vibration dial harder to read design
• ?vibration dial not required to fly regulation
• ?dial and plane not trained with simulator
• ?technology updated but not announced

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Vibration Dial 2

• ?vibration dial small design
• ?Without range marking design

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During descent

• ?lots of interruptions
• ?pilots cant see the engines
• ?no protocol no checking/confirmation visually
  from cabin
• Passengers could see fire but explained it away,
  perhaps also flight attendants
• ?diffusion of social responsibilities
• ?Social distance between aircrew and pilots

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crash

• 900 m short
• 434 out of 1188 die

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At crash

• ?Not documented noise abatement hillocks

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Afterwards

• If any 13?or 3? missing, no loss of life
• What was the pilot error?
• Thus, systems require understanding people,
  technology, and systems and environment

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References

• Wikipedia on kegworth
• BBC. (1991). Fatal error Taking liberties
  television series.
• Youtube has videos as well