Go Back  PPRuNe Forums > Ground & Other Ops Forums > Questions
Reload this Page >

Lightning Strikes?

Questions If you are a professional pilot or your work involves professional aviation please use this forum for questions. Enthusiasts, please use the 'Spectators Balcony' forum.

Lightning Strikes?

Old 18th Jul 2007, 10:11
  #1 (permalink)  
Thread Starter
 
Join Date: Mar 2006
Location: uk
Posts: 94
Lightning Strikes?

An aircraft went tech the other day because of a lightning strike. and has left me wondering a few things

1. What is it like in the flightdeck? is there a blinding white light followed by chaos or do a few warning lights come on and the flightdeck are put into action to work through any warnings?

2. Whats it like from the cabin, again is it a bright flash followed by being pitched into darkness and mass passneger panic or what ???????????????

3. What problems are associated with lightning strikes such as airframe, avionics and so on. I thought if an object had no contact with earth could not get electricuted or is it different. Any answers to explain any of the above would be greatly appreciated.
xxx5572 is offline  
Old 18th Jul 2007, 10:20
  #2 (permalink)  
 
Join Date: Feb 2006
Location: Netherlands
Posts: 310
From the cabin I can confirm that during daylight hours it is just a fairly bright flash followed immediately by a loud bang which can be felt through the structure of the aircraft (ie the floor of the cabin). Quite an interesting experience
perkin is offline  
Old 18th Jul 2007, 13:21
  #3 (permalink)  
 
Join Date: Nov 2002
Location: Heart of Europe
Posts: 193
two lightning strikes up to now:

First one in descent to Rome. Came out of the low buildup we were passing at about 1 mile!!! The only thing that happended was that the static which had built up during the preceding two minutes went away. And a flash pretty much the same as when hitting a speed trap. No sound but I could feel it on the controls. Later we found out that it entered at the nose wheel bay traveled along the lower side of the fuselage and exited on the elevator taking two static wicks with it.

Second one was at night. Only rain on the radar. St. Elmos fire on the windshield then from the right side of the aircraft a blinding white flash. Found static wicks missing their end parts on the right wing trailing edge after landing.

Lost no instruments - nothing

Lately I was flying an aircraft hit by lightning the previous day. Found a couple of inop instrument backlights and the GE found a couple of light fuses burnt.

Externals showed colour popped away from some rivets.

I hope my lightning encounters continue like this.
error_401 is offline  
Old 18th Jul 2007, 14:18
  #4 (permalink)  

Bottums Up
 
Join Date: Feb 2000
Location: dunnunda
Age: 62
Posts: 3,445
Took a lightning strike about 3 yrs ago, in a 146 with the F/O PF and still on climb. I was filling in the tech log and became aware that the F/O had ducked. This was followed by a loud bang.

F/O said the bolt hit the fuselage near the wiper post. No aircraft services lost.

After landing (we returned to departure aerodrome some 60nm behind us) Cabin Crew advised that they and pax observed a "fire ball" pass down the starboard side of the fuselage, just outside.
Capt Claret is offline  
Old 18th Jul 2007, 17:09
  #5 (permalink)  
 
Join Date: Feb 2006
Location: Netherlands
Posts: 310
With regard to my lightning strike as pax, it appeared to strike the fuselage some distance behind the flight deck - would the flight/cabin crew actually have any indication that this had happened? I'm curious as there were no PA's from the flight deck - I would've expected just a few words to say what had happened, nothing to worry about etc, as it could be a bit distressing if you were a nervous flyer. It was at a fairly high workload situation however - squally showers on descent quite close in to Gatwick, so perhaps not top of the crews priority list to be doing PA's...

Also, if you witness such events, or see something that looks out of place should you inform the cabin crew? I'm never too sure if I should point out things like that as I don't like to look like I think I know better than the crew
perkin is offline  
Old 18th Jul 2007, 18:21
  #6 (permalink)  
 
Join Date: Jul 2006
Location: USA, Ireland
Posts: 109
"Also, if you witness such events, or see something that looks out of place should you inform the cabin crew? I'm never too sure if I should point out things like that as I don't like to look like I think I know better than the crew "

Reminds me of the "Twilight Zone" episode where William Shatner saw a gremlin tearing up the wing in flight. Nobody believed him until they landed and looked at the wing.

Great show, did they ever have that one in Europe?

Seriously though, if you see something you are concerned about let us know. I'd rather explain something to you than be surprised by something you already knew about and I didn't. Just don't ask me the name of the river down below. They are all the Mud River if you really need to know!
acebaxter is offline  
Old 18th Jul 2007, 21:27
  #7 (permalink)  

Bottums Up
 
Join Date: Feb 2000
Location: dunnunda
Age: 62
Posts: 3,445
Perkin, they were probably sitting bolt upright saying to each other, "what the F was that?"
Capt Claret is offline  
Old 19th Jul 2007, 05:55
  #8 (permalink)  
 
Join Date: Aug 2003
Location: Sale, Australia
Age: 76
Posts: 3,829
Fairly good paper here on strikes with plenty of reference material http://www.lightning.ece.ufl.edu/PDF...encespaper.pdf

Video of a 747 taking off getting struck http://www.thaivisa.com/forum/lofive...hp/t44816.html
Brian Abraham is offline  
Old 20th Jul 2007, 11:33
  #9 (permalink)  
 
Join Date: Mar 2005
Location: UK
Posts: 527
I thought if an object had no contact with earth could not get electricuted or is it different.
It depends. In order for current to flow, there has to be voltage potential present. Lightening strikes because there is a potenital difference between the charged particles within the cloud and the ground.

Think of birds standing on high voltage cables. They aren't electricuted because their body is a fairly poor conductor. The electrons gain nothing from taking a detour though their body, they will follow the easiest path (the path of least resistance). If the bird were to stretch it's wing out and touch another wire of different potential, and there is sufficient current to overcome it's resistance (likely in high voltage cables) then it will fry!

An aircraft will behave like a Faraday Cage, causing the induced current to flow through the airframe and not it's occupants.
TotalBeginner is offline  
Old 20th Jul 2007, 13:43
  #10 (permalink)  
 
Join Date: Sep 2005
Location: No one's home...
Posts: 416
1. What is it like in the flightdeck? is there a blinding white light followed by chaos or do a few warning lights come on and the flightdeck are put into action to work through any warnings?
2. Whats it like from the cabin, again is it a bright flash followed by being pitched into darkness and mass passneger panic or what ???????????????
In both cases, big flash and big boom! It is like Mother Nature taking your picture with a REAL BIG camera!
3. What problems are associated with lightning strikes such as airframe, avionics and so on.
First there are two kinds of strikes but the point is moot since you don't have a choice of which one hits you. A negative lightning strike will usually just cause some pitting at the exit point and it can affect some instruments. Because lightning is considered part of flying, aircraft must show they can take strikes as part of certification. So, your instruments and the electrical systems are shielded and grounded so the main thing after taking a strike is to just continue to fly the airplane.
A positive lightning strike, somewhat rare as it is estimated to be only 10% of the strikes, is about 10 times bigger than a negative strike and it tends to knock stuff off the airplane such as parts of ailerons, flaps, antennae, etc.
And aircraft that are made solely of composite material may be at risk. In Germany a few years ago, a composite sailplane took what is thought to be a positive strike. The strike BLEW up the sailplane. Fortunately both occupants were wearing chutes and survived.
The greatest risk for lightning is crossing the ramp to get to/from the airplane while a storm is brewing.
wileydog3 is offline  
Old 22nd Jul 2007, 13:15
  #11 (permalink)  
 
Join Date: Jun 2007
Location: In the workshop, Prune-whispering.
Age: 67
Posts: 740
Quote:
1. What is it like in the flightdeck? is there a blinding white light followed by chaos or do a few warning lights come on and the flightdeck are put into action to work through any warnings?
2. Whats it like from the cabin, again is it a bright flash followed by being pitched into darkness and mass passneger panic or what ???????????????

Been hit twice in a Nimrod. I was down the back at the time of the strike which hit the nose. It made a hole about 10" across on the radome, hit the radar scanner and travelled through the inside of the airframe. This appeared as a bright purple/blue'ish ring around the inner circumference of the cabin travelling rapidly from the front to rear of the aircraft, exiting via the MAD boom on the tail. It literally made our hair stand on end. Quite funny, no major damage apart from the nose and radar scanner.

PingDit
PingDit is offline  
Old 23rd Jul 2007, 05:18
  #12 (permalink)  
 
Join Date: Jun 2006
Location: anywhere
Posts: 121
hit once in an electra.

just forward of the f/o windscreen.

blinding flash, explosion like sound. punched about 9 holes(small 2-3mm) in the fuselage.

interestingly saw in a previous post st elmos. we had st elmos, never saw it before in electra and never saw it after that night.
ithinkso 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


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.