Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

Lightning Strikes

Wikiposts
Search
Tech Log The very best in practical technical discussion on the web

Lightning Strikes

Thread Tools
 
Search this Thread
 
Old 30th Aug 2007, 18:54
  #1 (permalink)  
Thread Starter
 
Join Date: May 2000
Location: London, UK
Posts: 391
Received 7 Likes on 4 Posts
Lightning Strikes

Was SLF on a flight recently that was struck by lightning - on the nose, out through the wing tips.
Does it always hit the nose, and if so why?
SLF3 is offline  
Old 30th Aug 2007, 21:20
  #2 (permalink)  
None but a blockhead
 
Join Date: Nov 1999
Location: London, UK
Posts: 535
Likes: 0
Received 0 Likes on 0 Posts
At the risk of being SLF answering SLF, and basing my answer on stuff I've read, physics I've been taught, plus some experience playing with home-made EHT generators... (in other words, zero appropriate actual experience!)

Electrical discharges to or from a conductor (lightning is either from a charged area to a conductor, which is the case with ground strikes, or from area to area, which is what happens with lightning within clouds) favour the area with the highest potential gradient. That often equates to pointy bits. Aircraft attract lightning when they fly into a zone where a strike is imminent, because (among other factors) they offer a conductive shortcut which pushes local conditions just past the trigger point. The biggest potential difference is normally across the airframe, nose to tail, because that short-circuits the biggest distance, and because those bits are reasonably pointy it enhances the chance that lightning will take that path.

There are plenty of exceptions to that. Lightning may be predictable in the general case, but it's extremely weird strike by strike.

So; yes, it will tend to hit (or exit via) the nose. No, that's not a hard and fast rule. And I am, at best, an enthusiastic amateur in these matters who has utter faith in Faraday cages (although Apollo 12 remains perhaps the most extreme test of such matters).

R
Self Loading Freight is offline  
Old 31st Aug 2007, 10:47
  #3 (permalink)  
 
Join Date: Aug 2007
Location: Reet here
Posts: 15
Likes: 0
Received 0 Likes on 0 Posts
Lightning (and other) strikes

Please excuse my maiden post on PPRUNE... (I've been a long-time lurker, though!)

Faraday cages etc all being well, but how are sensitive electronic instruments protected under these circumstances? This question comes about after some colleagues and I viewed a YouTube snippet on 33KV repair teams using helicpopters to maintain high-voltager lines.
Somph is offline  
Old 1st Sep 2007, 07:55
  #4 (permalink)  
 
Join Date: Jun 2006
Location: Berkshire, just
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Lightning Strikes

Time for me to de-lurk as well!

I was fishing round researching the same question - about effect of lightning strike on avionics - when I came across an article from "Progress in Aerospace Sciences".

Let uncle google do the work using "effect of lightning with airborne vehicles" as the search string, and the article should come out top of the heap.

The article provides some interesting background reading, and should help the approaching winter nights just fly by....

Last edited by ClutchingAtStraws; 1st Sep 2007 at 07:59. Reason: Fat fingers
ClutchingAtStraws is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.