Re: Fear of Flying

Date:         16 Dec 96 03:15:39 
From:         tgg@hplb.hpl.hp.com ()
Organization: Hewlett-Packard Laboratories, Bristol, England
References:   1 2
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M Carling (m@ml.com) wrote:
|The probability of one engine failing in mid-flight on a 747 is less than 1
|in 1000. Since the sources of multiple engine failure (aside from running out
|of fuel) generally occur at low altitudes, the probabilty of all four engines
|failing in mid-flight on a 747 is probably lower than one in
|1,000,000,000,000.

You are  erroneously  assuming that each engine failure is independent
of the other engine failures. Counter-examples:
	- the BA 747 that flew into a volcanic dust cloud over
	  Indonesia with the loss of all four engines. I believe it
          took >15 minutes to restart one of the engines
	- faulty maintenance
	- no fuel
	- and others, no doubt

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            The above are my own views, not the views of HP
  Tom Gardner                 Hewlett Packard Laboratories, Filton Rd,
  tgg@hplb.hpl.hp.com	      Stoke Gifford, Bristol, Avon, BS12 6QZ, ENGLAND.
  Fax: +44 117 9228924        Tel: +44 117 9799910 ext. 28192
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