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Pan Am 214 - Positive bolt strike?

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  • Pan Am 214 - Positive bolt strike?

    Is Pan Am 214 the only known instance of a positive lightning strike downing an airliner in aviation history?

  • #2
    There is a theory that Pan Am 214 was the victim of positive lightning. However, at the time (1963) aircraft lacked the static discharge wicks we see on all modern aircraft, so it is also plausible that convential lightning was to blame. Positive lightning can traverse great distances from convective cells and strike where no threat would be expected so they are just one of those unlikely things in life, like meteoroids, that we have to accept. Fortunately, to my knowledge, they are extremely rare and no other crash in 50 years has been attributed to positive lightning strikes.

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    • #3
      Originally posted by Evan View Post
      Fortunately, to my knowledge, they are extremely rare and no other crash in 50 years has been attributed to positive lightning strikes.
      Well, probably not what you had in mind, but here you have one modern case:

      Recommendation No 99-49 It is recommended that the CAA should request serious consideration, during its participation in the current international review of aircraft lightning certification standards, of the fact that energy levels from positive polarity discharges have been shown to greatly exceed those specified in Advisory Circular AC 20-53A, with the associated implications for the certificated lightning protection assurance of existing and future aircraft designs, particularly those which utilise significant amounts of composite material in their primary and control structures.

      --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
      --- Defend what you say with arguments, not by imposing your credentials ---

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      • #4
        Originally posted by Gabriel View Post
        Well, probably not what you had in mind, but here you have one modern case:



        http://web.archive.org/web/200410092...ty_500699.hcsp
        They can consider all they like. I doubt any defensive technology capable of flight can withstand that kind of energy.

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        • #5
          Originally posted by Evan View Post
          They can consider all they like. I doubt any defensive technology capable of flight can withstand that kind of energy.
          And yet, the standard was improved and replaced by AC 20-53B in 2006.
          http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/df13a258a81c1c158625718500571274/$FILE/AC20-53B.pdf

          If I am not mistaken, this is the one Boeing had troubles to comply with for the 787 and requested the FAA an alternative means of approval.

          Does it cover positive lightnings?
          I don't know.

          --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
          --- Defend what you say with arguments, not by imposing your credentials ---

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