Lightning strikes

[Married a Canadian]

Poor weather in Toronto yesterday and quite afew aircraft were getting struck by lightning. Poor BA and Air France got multiples!

I have never been on an airline when it has been struck. I know that all modern airliners are equipped to deal with it but from a cockpit perspective I would be interested to know what happens when you are struck?. Lights flashing, instruments flicker etc etc.

How accurate is the weather radar in cockpits nowadays?

Just curious

[mcdhu]

....in my limited experience of (3) lightning strikes, all you really notice is a VERY LOUD BANG !!!!

Cheers
mcdhu

[LastCall]

Was in the second spin in the OCK hold at FL090 one morning last October. The conditions weren’t the best, as we were holding in towering CU with heavy rain and continuous moderate turbulence. It wasn’t very comfortable. As we started the turn back to OCK from the south end of the hold the F/O read my mind and stated, quite prophetically, that the conditions were about right for a lightning strike.

No sooner were the words out of his mouth when there was a bright flash on the left side and the immediate clap of very loud thunder, which drew my immediate attention to the screens & instruments. Not even a flicker! Everything continued normally.

It didn’t surprise us too much as we were both expecting it. I think it would have been quite spectacular had it been at night.

Inspection on the ground revealed a bit of scorching at the strike point on the left engine intake cowl, with the exit point at the aft end of the engine. Otherwise, no damage and no adverse instrument effect.

As far as the radar goes, it is very accurate for rain. But in a small space, like in a hold and the immediate approach area, you tend to use the short ranges which are going to show the rain to be everywhere, so it isn't going to tell you what you don't already know. Also, at the short ranges, like 20 miles and less, the radar tends to be overly sensitive and in a lot of cases makes things look worse than they really are. It's best used on the medium to longer ranges for weather avoidance.

[Human Factor]

I got struck out of YUL at night a few months ago. Huge bang and all the screens went to full brightness. Otherwise ok, until we got to the Atlantic and found none of the HF radios worked!! CPDLC and Satcom got us across and we found a large scorch mark just below the flight deck on arrival.

[Dani]

All the above is correct. The problem is that lightning also can happen outside of a thunderstorm cloud or propagate from inside to the outside.

The results of a lightning strike can be manifold, from nothing happening to holes in the structure to instrument and other components failure. The complete instrument failure can happen, but it is rare, and according to my observation rather happened on the last generation electro-mechanical generation than on the latest gadgedery.

I had one a multiple lightning strike on a turboprop and after the flight it showed that the lightning entered the cell, exited and reentered again, thus producing three holes in the upper left front fuselage. Those holes can be from tiny to one or two centimeters in diameter (that's up to an inch). But surprisingly the cabin pressure isn't really an issue, because the bleed system can provide more pressure than air is leaking.

Interesting lightning strike had been observed when lightning entered the cockpit and/or cabin and generated some light shows.

Dani

[tilewood]

I was in a Canadair CL44 turbo-prop freighter enroute from Lagos to Kano in the 1970's when we were struck one night.

St Elmo's fire turned the windscreen laminate into a mass of purple veins,
like a leaf, and the tips of the propellers looked like Catherine Wheels!

When we arrived at Kano and did a walk round there was a small hole
in the skin near the base of the fin. Apart from that the aircraft was
fully serviceable, and it did not affect the integrity of the pressure hull.

The turbulence was interesting though!!

[skywerd]

Don't look now, but the ERJ that I fly is very susceptible to lightning strikes. The company for which I work has had numerous lightning strikes.
On the ERJ, instruments are often affected, holes are left in the nose,tail and sometimes the wing.
Several of our aircraft, after being struck by lightning, had constant static in the radios. On further inspection, it was found that the static wicks were burned to a veritable crisp.
The worst scenario, however, is one in which the elevator cables weld to the frame of the aircraft. We have had two aircraft do just that.
Rumor has it, however, that each of our aircraft, just prior to being struck, were in the following configuration:
1. Down low and slowed down for turbulence.
2. Radios began to "crackle" and "hiss" (all ERJ pilots know what I am talking about).
3. The smell of ozone came, then the "big bang."
The loud bang was so loud in one aircraft that the flight attendant, who was sitting in her jumpseat at the time, had an ear drum rupture.
So much for lightning strikes being benign.
Somebody help me get on with CX....:sad:

[Human Factor]

Forgot to say, we lost about half a dozen static wicks...

[nostep737]

Last year going into BKK on a dark night with to much traffic to go around the red wall of death so through we went, we had vertical lighting all around then one big flash (luv the smell of ozone) a big flicker and my symbol gen fell over then suddenly it wasnt fun any more, got through and landed ok and on looking found we had being hit in the engine cowl put a nice big hole in scary stuff, I think a common place for 737's

[Greenfinch]

Been hit a few times - no big deal, just a bright flash and a bang (one was pretty loud, but had a couple that were just a dull 'thud'.

That said, I once saw the wreckage of a glider that was hit - it peeled open like a banana and the alloy aileron pushrods were just lumps that had been completely melted ! (luckily the 2 crew had parachutes and escaped with minor injuries and brown underpants !!!).

[steinycans]

http://www.pprune.org/forums/showthread.php?t=178656&highlight=Lightning

[phnuff]

From a passenger perspective, I was in cattle class on a KLM 747 combi which got hit about 10 minutes before landing at AMS. There was an intense purple light in the cabin, a slight bang, the lights flickered and it was over (for us) although for some reason which I cannot explain, I got the feeling of being near a lot of energy. The Captain announced that there had been a lightning strike and not to worry

(I love the video above btw)

[Lou Scannon]

I once got struck in a Fiat car at 8,000 feet over the Central Massif!

Well actually, I was sitting in the car that was in the back of a Hastings when that took the strike. I went back up on the flight deck to find one chap who had his helmet off sitting there with his hair standing on end, a smell of sulphur and the compasses spinning round.

Fortunately the trailing aerial had been wound in so there was not too much damage to the signallers kit (or the siggy) and we had one VHF set still working. Paris and London gave us compass less guidance and we continued to a landing at Lyneham.

The aircraft was bonded but not as well as they are today.

One more amusing fact. In those days the ops manual stated that when freighting it was a good idea to fly into the odd Cu-nim to give the pilots practice at turbulence flying!

[Rainboe]

At 17000', 747 descending into BDA in heavy cloud, a stream of not brilliant lighning appeared coming through the cloud dead ahead streaming straight to the aeroplane. It must have lasted about 6 seconds or more. We had that funny atmosphere you get- our hair was standing on end because we were really scared- it looked at if it was heading straight between each of our knees. Ended with a very big flash and bang. I simultaneously felt something like a flick on my watch, which was new and rather expensive, but undamaged. That was one of the unusual strikes. Lots of flashes and bangs and holes made, but the scary stories are the ones about ball lightning appearing in the cabin and wandering about for many seconds. Still nobody knows anything about them. A prize for the first guy with the guts to stick a finger in one!

[Elroy Jettson]

Watched a great doco on Discovery channel about sprite lightning. Google it or check this out. http://www.newscientist.com/channel/earth/dn8733.html.

They think designers will have to rethink how much energy will have to be dissipated through bonding...

They are attributing it to a number of previously unexplained hull losses. One of them a Pan Am B707!

Interesting stuff!

Anyone seen ball lightning cruise down the cabin? Or is that the aviation yeti equvalent?

(Holding inside towering CU? Seriously? :eek: )

[Mod Flight 1]

I remember a 747 taking off from Heathrow that got struck. The crew saw some fluctuations in the engines and a bang. Everything seemed normal. Landing in Toronto the lead noticed something and advised the captian.

There was a 2 foot dent in the nose from where they were struck.

:ooh:

[Tired Old Man]

Lightning & ball lightning are very complex phenomena see link for some interesting information.

http://www.amasci.com/weird/unusual/bl.html

Regards

[Frangible]

Metal a/c seem to do well with lightning. But what about composites? AAIB report into a Super Puma ditching -- lightning strike caused a composite tail-rotor blade to fail -- suggested that lightning protection standards were set way too low because the failure occurred at an unexpectedly high charge, four or five times higher than the max envisaged in the standard. Then and now, there haven't been enough lightning encounters with planes with a high proportion of composites to see this work out in real life. The current standards may be good enough for metal, but possibly not for composites. Interesting question for A380 and B787.

[Rainboe]

Elroy, I knew a steward who swore to me this story was true. He and a stewardess were sitting in the rear vestibule seats of a VC10. They're by the door right back between the engine intakes, so very noisy. Night, seat belt signs on, turbulence, facing rear, trying to hold a conversation. Around the bend next to his shoulder a ball of lightning had come down the cabin, gently around the bend and floated gently past them at shoulder height, heading towards door, moving very slowly. It then passed through the door and disappeared. Very funny atmosphere, hair on end (it would be!), stewardess hysterical, unable to swallow. Several other similar incidents known over the years in BA.

[ALLDAYDELI]

I heard a similar story on the BA285 B747-200 going LHR-LAX back in late 90s.
I watched it take off and saw it get struck by lightening somewhere Slough direction. Pax in question said the flash entered the cabin forward and exited rear. I didnt see that bit.

[captjns]

The two lightening strikes I've experienced started with a hiss increasing in volume followed by a loud report. On resulted in a 2" hole in the horizontal sabilizer which drilled a hole in the hinge plate. No loss of generators or inerruption of nav/comm resulted in either strike.

[JW411]

We have had this conversation before on a previous thread but I have sat through a ball lightning event once about 40 years ago over the Massif Centrale at night.

The ball appeared on the flight deck went downstairs and worked itself backwards through the cabin and exited the aircraft to the rear.

No damage was done apart from several underpant changes but I remember the dust and general crap that had been lying around for years behind the instrument panel suddenly being in suspension.

Afterwards, the loadmaster was quite adamant that he saw the ball come down underneath the wing and enter the aircraft.

[JackOffallTrades]

Got struck once. Climbing through fl70 between two cells. Thought we had lots of clearance from them both. Wasn't expecting it. Big bang and a flash. Incredibly bright, it went in infront of my windshield and out the elevator trim tab. Since then I've been alot more cautious around cbs.

[perkin]

I'm not a professional here, but I was pax on a flight that was struck by lightning on the approach to Gatwick in December of all times, while flying through a very heavy shower...Seemed to strike the fuselage just ahead of where I was sitting (or does it pass along the fuselage, giving the effect of it striking ahead of my window? I'm not too sure of the mechanics/physics of lightning strikes) and there was just a very loud 'crack' and obviously a nice flash too. Didn't seem to be a particularly big deal, but made a few fellow pax go a bit quiet...! It certainly gave the 737 a fair old thump which I felt through the floor...An interesting experience!

[outoftheblue]

PAX on BA 737 EDI-LHR February 2001 on downwind leg to 9L. Lightening hit nacelle directly outside my window. Deafening bang that was over v.quickly and wing lit up green which would probably have been quite pretty but I was contemplating my imminent death.
Captain came on straightaway and said that some of us might have noticed a little bang (a little bang! It probably was up the sharp end!) but a plane was the safest place to be when lightening strikes and we would be landing in 5 mins.
As we turned onto what turned out to be a short final we got hit again! Everybody was anxiously awaiting the reassuring tones of the Captain but none came. He had his hands full with the landing and we all had white knuckles!!
:eek:

[haughtney1]

B757 on descent into Murcia last summer...Id literally just said to the Capt that the CB's we were dodging around seemed very tame.....then BANG BANG BANG, three strikes in about 2 seconds..with the last one just below my DV window...various expletives then uttered..and umbridge paid to murphy :uhoh: :}

[Capt Claret]

MaC,

I took my first known strike in Feb last year. The F/O was the pilot flying a BAe146-200 - analogue instrumentation.

Whilst completing some paperwork I noticed him duck. This was followed by a flash and an almighty bang. Once the F/O's heart started beating he advised that the lightning had struck the nose, near his windshield wiper post.

Sadly there was no damage to the aircraft or any of its components. It was a dog of a machine and whilst we didn't want it to fall out of the sky, we wouldn't have been at all sad if it was determined upon inspection, to be unsalvagable.

Oh, and after we'd landed and disembarked the pax, the F/As advised that they, and many of the pax had seen a fireball pass down the starboard side of the aircraft, outside not inside.

[Ultralights]

Sadly there was no damage to the aircraft or any of its components.. :confused: :confused:


seeing as there is plenty of us who have experienced Lightning strikes, Ball Lightning, and St Elmo's fire, there surly must by some photos of such events?? i have never seen st Elmo's fire, but would love to see a pic of it!

[Dan Winterland]

I've been struck several times and received shocks twice. The first was in a composite glider. There was no damage to the airframe but my left hand was on the airbrke lever and the charged arced from the metal part of the lever ovedr the plastic grip and hit my palm. I still have the scar today.

The second shock came in a VC10. I always thought that a metal airframe should a act as a farady cage and protect the occupants. Not so in this case. The strike was on the refuelling probe just above the radome. I was the PNF and was transmitting - telling ATC we were deviating for weather! The shock went throught the left pedal, up the left side of my body and through my left hand. The F/O felt a shock through both feet and lightning path went through the centre of the cabin. Everyone was sitting down so no-one in the cabin was struck. The aircraft had holes in the refuelling probe and both wingtips. I get aches up the left side of my body, parcticularly in the left wrist and ankle.

[kenparry]

I had only 2 strikes in 20+ years of airline flying.

First on a B737 going into NCL, about 6 miles finals, only moderate Cu around. No warning, big flash, big bang, as we got a strike on the nose just outside the FO's front window. No effect on the aircraft at all. We did find a small burn mark on the nose afterwards.

Second was on a B767, again on the nose, very similar.

For some years I monitored the stats of my (former) employer's fleet, and the rate was about 1 strike per airframe per year, utilisation being about 4000 hr per year.

[Doors to Automatic]

Can commercial aircraft withstand a rare positive strike (as opposed to the far more common negative) as this is many times more powerful?

[False Capture]

Ultralights,
Try this link:

http://www.airliners.net/open.file?id=1024173&size=L&width=768&height=1036&sok=&photo_nr=&prev_id=&next_id=

[airship]

Not a lot of people know this I'm told, but just before lightning strikes an airliner, the GPWS will often go off with a whoop whoop pull up... :O

(Hope it makes more sense here False Capture) :confused:

[Farrell]

Lots of this phenomenon can be experienced around France at the moment :E

[banewboi]

hi guys

i was involved in an incident over the mid atlantic, mid turbulence (the usual do) and everythin went quiet. there was a low pulsing purple light that went from front to back (767-300 series) really really slowly, like if you watched a flourescent tube come on from one end over 5 mins in slow motion and then it was gone.

scorch marks below flight deck and apu!

[212man]

It can be fairly bad news for helicopters; composite blades, sharp angles at the tail rotor tips, lots of gear teeth to spot weld each other etc. My last company lost an aircraft shortly after a strike (tail rotor shook itself to bits) but the 18 POB survived the ditching, and another a/c lost a main blade that had been previously damaged (but cleared as serviceable by the manufacturer) in a strike. sadly, you don't survive blade shedding!:(

[blue up]

Seem to remember an FO in the UK losing his medical after a strike hitting the side window and Btzzzzing him. Might (?) have read it in the Balpa mag years ago.

btw. 14 scorch marks on my 757 passing a single small cell at 12,000 over POS vor near Palma,Majorca. No night stop, though (bugger!)

[Charles Darwin]

This is how it can hit you. Has some negative side effects on the weather radar :ugh: .
http://img107.imageshack.us/my.php?image=00000299xv.jpg

[DC10RealMan]

I was a passenger on a flight on finals for LHR once. A load bang occurs when the aeroplane gets a lightning strike. The five year old boy in the row in front of me leaps to his feet and exclaims "**** me!, What was that!. The cabin was in uproar, but not his parents I hasten to add.

[aidey_f]

There is an interesting AAIB report into a lighting strike on an Embraer ERJ here:

http://www.aaib.dft.gov.uk/cms_resources/G-RJXG_11-05.pdf

Potted version:
Looks like the hot air from the lightning discharge along the fuselage caused an EGT overtemp so the FADEC shut down the engine. An interesting report, particularly the recomendations at the back end.

[Dan Winterland]

If composite structures have not been weather proofed properly nad have absorbed a bit of water, this can be a real problem apparently. The water boils, expands and bursts the structure. This is what may have happened to the 757 radome.

[Elliot Moose]

I heard of a scary incident last week (around April 07) about a Continental flight going into Calgary having been struck by lightning. The FO reported being down to standby instruments only and since the weather in YYC was near minimums, they were asking for help getting up to Edmonton where it was clear.

Has anybody else heard about this incident?

[dollusa]

happened to me long time ago ...a loud bang...after landing we discovered that the HF Ant. wa melted off.

[mach79]

Dan,

Interesting experience, hope you don't mind me pointing out it is in fact a Faraday cage named after Michael Faraday-he really was a genius.


http://www.rigb.org/rimain/heritage/faradaypage.jsp

[2dotsright]

I loved reading about all the lightning strikes you guys had, character building I reckon. No mention about brown stains in the underdaks though, and no doubt there's been a few. ha ha ha!! I had a few myself (brown stains and lightning strikes that is) Worst in Dhaka a few years ago but must relate the beauty outta Gatwick one day. The F/o (now Capt) will now know who I am but what the hell. I told him he had no balls for dodging a rather small cell on the radar at low level and then "Kabooomm" , we got whacked. Always maintained that if we'd have flown straight into it we'd been ok, that's my story and I'm sticking to it. Best part was the Fleet Mgr was paxing and it seemed to frighten the crap outta him. Fun Hey ha ha ha ha!!!

[JohnWaynePlane]

Got hit going into MEX it was like a speed bump in a lada a bit twitchy but not too bad cc said it was like being hit by a bomb - in the virgin steweradess styleee "Were all going to die" ! ! ! ! ! !

[CashKing]

A new program in theoretical modeling of the apertureless NSOM data has obtained results based on modeling of the AFM tip, prism surface, and evanescent laser field by discrete electrostatic multipoles, and matching boundary conditions at the respective interfaces with least squares methods. Most importantly, these calculations can be converged for realistic elongated tip shapes that incorporate the lightening rod antenna effect and the actual exponential drop off of the evanescent fields. The results indicate (i) a significant enhancement of the fields near the tip, (ii) a strong sensitivity to the length of the tip elongation, and (iii) a limiting value of the field enhancement of http://physics.nist.gov/Images/kappa.gif http://physics.nist.gov/Images/approx.gif 30 for tip lengths greater than the 1/e evanescent decay. This value is in remarkably good agreement with what is observed experimentally. Furthermore, this analysis indicates a significant contribution to near field enhancement from "image dipoles" generated in the prism when the laser polarized AFM tip approaches within approximately one tip radius (5 nm) of the surface ("Narscissus effect").

[Rainboe]

Cashking, I think you don't understand that this is not a university forum, it's a practical forum for people who fly (and some nutty people called 'Jetblasters'- they're very weird- don't go there! Might I direct you to 'Agony Aunt' where the assistance you need will be available?). We don't want to go through the mathematics, we actually go into thunderstorms with umbrellas (and aeroplanes) and want to know how not to get hit, not the square root of the urban displacement times the Youngs Modulus x 30 power 'n'!
You are overdazzling us with phony science!
http://www.pprune.org/forums/showthread.php?t=222147

What you are saying is nonsense with defining 'NSOM' and 'K', and what is that garbage about 1/8 evanescent decay?

[CashKing]

Firstly, let's discuss the specific features of the physico-chemical transformations of the lightning storm air in a wide temperature range. In the lightning storm atmosphere nitrogen oxides, ozone and other "combustible" components start to accumulate reaching concentrations in excess of the normal levels (sometimes by several tent olds). Thus, nitrogen oxide is synthesized through -the following process: http://www.endeav.org/evolut/text/ball/image149.gif (1)
where: the reaction heat effect http://www.endeav.org/evolut/text/ball/image150.gifrelates to standard conditions. Having entered the low-temperature zone, http://www.endeav.org/evolut/text/ball/image151.gifis "tempered" [15,16] and can react with oxygen and ozone as in the below equations: http://www.endeav.org/evolut/text/ball/image152.gif (2)http://www.endeav.org/evolut/text/ball/image153.gif (3)
Under the lightning storm conditions the processes described by the cumulative equation of the below type become significant too: http://www.endeav.org/evolut/text/ball/image154.gif (4)
The created http://www.endeav.org/evolut/text/ball/image155.gifdissociates in rain drops and fog particles in the following way: http://www.endeav.org/evolut/text/ball/image156.gif (5)
It should be noted that http://www.endeav.org/evolut/text/ball/image157.gif, also a product of the cumulative process, is similarly unstable even at low temperatures and in the liquid phase decomposes into http://www.endeav.org/evolut/text/ball/image158.gifand http://www.endeav.org/evolut/text/ball/image159.gif. In addition, there are other known processes of the type: http://www.endeav.org/evolut/text/ball/image160.gif (6)http://www.endeav.org/evolut/text/ball/image161.gif (7)increasing the liquid phase conductivity by several orders. The reactions of http://www.endeav.org/evolut/text/ball/image162.gifand http://www.endeav.org/evolut/text/ball/image163.gifdecomposition in the gaseous phase under the appropriate conditions can generate some amounts of ions as well.

[212man]

Cash King seems to have taken to large scale cut and pasting (have just been browsing the magnetic/GPS thread).

Possibly trying to be helpful, but in reality not!

[rubik101]

Whatever all that stuff above means, I have no idea. My dear old Mum used to delight in telling the tale of a flight from Geneva to London in a York in the fifties. She was sitting in the first row when she heard a bang and and watched incredulously as a glowing white ball filled the whole fuselage and rolled/moved down the ailse at about the speed of a running man, whatever that might be, and dissapeared out of the tail of the aircraft.
I have no reason to doubt her story, well, she is my Mum, after all.

[Evening Star]

Whatever all that stuff above means, I have no idea

Quite simple (says somebody who looked at a probability based method of determining lightning induced damage as a dissertation for my first degree):

1. It is possible to theoretically calculate the propogation of lightning.
2. Lightning fixes free atmospheric nitrogen.

The first is useful in designing structures against lightning strike, but fairly irrelevant here. The second is an important part of our planetary ecosystem but has diddly-squat relevance to those of you at the sharp end pondering the cell in front of you. To be honest, I think CashKing is being a bit of a 'cut n paste intellectual'.:}

[Tight Slot]

hmmm, good stuff! Well here's my little story... Into MAN in a B757, RVR 300 mts in snow, cross wind of 16 kts, so had to brief for an autoland. Comming onto base leg around 4500ft we got hit big time on the nose at night. Saw the whole bolt and strike, its only around 20mm thick!! After making sure my underpants were'nt wet carried on with the app. Next thing I know is the No 1 came in and said "have we just been hit?" I said, yeah, erm, how do you know? she just said " oh just a hunch when a ball of lightning shot down the first 11 rows, then ran out over the wing!"

After landing (good work Mr. Boeing) got to see a 10mm hole in the raydome.

Tend to avoid these days.