A Question On Charged Clouds, Discharging, And Lightening

1. 81

   quicksandposted 10 years ago

   A Question On Charged Clouds, Discharging, And Lightening
   
   A highly charged cloud moves over a flat terrain. In order to discharge and cause lightening to strike, a very slight elevation in the terrain is all that is required. This elevation would reduce the "spark gap" and then lightening would strike. Before it reaches that critical point, an aircraft flies between the charged cloud and the terrain. Obviously the metal body of the aircraft will reduce the spark gap. In such a case will the body of the aircraft facilitate lightening and will the aircraft suffer damage?
   
   

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2. 84

   SidKempposted 10 years ago

   Yes, the airplane's outer metal skin would be likely to attract the lightning. A bolt would likely strike the plane. The plane is metal, and carries and electrical charge determined by the charge in the air at the altitude in which it is flying, which is differential between the earth and the storm cloud.
   
   This is one reason it is better to fly above rain than through it or below it.
   
   However, airplanes are well-designed on this issue. Generally speaking, a lightning strike to an airplane will not damage critical systems or injure people.

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   1. 81

      quicksandposted 10 years agoin reply to this

      Thank you very much SidKemp for the clear answer.

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3. 78

   A Little TRUTHposted 10 years ago

   To add to SidKemp’s excellent answer, any lightning bolt that hits the plane cannot be very large.  This is because the capacitance (ability to store electrical charge) is very small compared to the earth.
   
   Think about it this way:  If you get yourself all charged up by shuffling your feet on the carpeting with leather or plastic soled shoes on a dry winter day (if you live in the North) you can give someone a really big spark and a jolt.  But if you try to discharge yourself into a paperclip sitting on a rubber mat, you may not get a spark at all.

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      SidKempposted 10 years agoin reply to this

      Good point - the primary charge is in the Earth, not the cloud, and the plane has less charge than the Earth. I was forgetting that lightning goes upward!

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   whonunuwhoposted 10 years ago

   I learned a while back that lightning travels from the ground up. which was quite surprising. Most airplanes are well constructed and few suffer negligible damage after strikes by the lightning. I would advise against standing on top of a stunt plane in a lightning storm, however, and try to stay a little closer to the ground. whonu

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   1. 81

      quicksandposted 10 years agoin reply to this

      Yeah, it happens so quickly that you would hardly notice the start and the finish!  I'll take your advice and lie flat on the ground during a storm!  Thanks for commenting !!!

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5. 81

   quicksandposted 10 years ago

   Hi, A Little TRUTH, thanks for your example too. Much appreciated.

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