Lightning Strike
Thread Starter
Joined: Jan 2008
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From: London
Lightning Strike
Just leaving Singapore today, in a 777, in the climb just about time for the seatbelt sign to be turned off, there was a loud pop from the left side of the aircraft, and my girlfriend saw a flash.
We seemed to level off for five minutes or so (that may have been coincidental) and then carried on climbing, seatbelt lights were switched off, and we carried on the flight.
We later mentioned the pop to a flight attendant who hadn’t heard it, but her colleague overheard and said it has been a lightning strike.
Was a total non-event, but I’m just curious…
How often does that happen? Would a pilot expect to experience it every so often, or is it a couple of times in your career kinda thing?
Would you expect to have any indications in the cockpit, anything trip out etc?
Did I imagine it that they levelled out the climb, would that be normal to check everything was ok?
Like I said, was a total non-event, I’m just curious! Thanks in advance…
We seemed to level off for five minutes or so (that may have been coincidental) and then carried on climbing, seatbelt lights were switched off, and we carried on the flight.
We later mentioned the pop to a flight attendant who hadn’t heard it, but her colleague overheard and said it has been a lightning strike.
Was a total non-event, but I’m just curious…
How often does that happen? Would a pilot expect to experience it every so often, or is it a couple of times in your career kinda thing?
Would you expect to have any indications in the cockpit, anything trip out etc?
Did I imagine it that they levelled out the climb, would that be normal to check everything was ok?
Like I said, was a total non-event, I’m just curious! Thanks in advance…
Thread Starter
Joined: Jan 2008
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From: London
Wasn’t as loud a bang as I would have imagined really, but fairly startling. My initial guess was lightning, but then wondered if it had been a bird (although too high for that to have been likely). The flight attendant sounded like she’d been informed that it was the former…
Joined: Dec 2001
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From: GA, USA
A lightning strike is LOUD like temporary hearing loss loud.
I had a window seat in business class in a 737 and I was leaning against the side kinda glancing outside when a blinding flash occurred and this was as loud as a gunshot without hearing protection.
i had temporary hearing loss in my right ear.
Next day my eardrum was still sore.
So my best guess is in your case a lightning strike occurred in the vicinity of the airplane but didn’t actually hit it.
I had a window seat in business class in a 737 and I was leaning against the side kinda glancing outside when a blinding flash occurred and this was as loud as a gunshot without hearing protection.
i had temporary hearing loss in my right ear.
Next day my eardrum was still sore.
So my best guess is in your case a lightning strike occurred in the vicinity of the airplane but didn’t actually hit it.
PPRuNe Handmaiden
Joined: Feb 1997
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From: Duit On Mon Dei
It depends on where it hits as to what we'll see. Most of the time it's a non event and if it hits the tail, you may not even know about it.The aircraft is a Faraday cage and so well "armoured" against them. The engineers find evidence during the big inspections where they'll find signs of arcing and or welding.
Checkers had a strike on the edge of the windshield. He said that was loud. But not as loud as the collective"F*CK" exclamation by him and the FO. The cabin crew and the first 3 rows heard it.
Checkers had a strike on the edge of the windshield. He said that was loud. But not as loud as the collective"F*CK" exclamation by him and the FO. The cabin crew and the first 3 rows heard it.
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From: Beyond the Blue Horizon
Telster
Had it a few times as a SLF, especially in SE Asia and Mid West US in late Spring / Summer and occasionally in Europe in the same period with no issues, but I have never seen the strike like B2N2, just heard it at a distance, but A/C are designed with strikes in mind. I am more concerned with the turbulence you get associated with Thunderstorms than the lightening, which can look pretty especially at night along with St Elmo's Fire. Thanks for posting of your experience.
Cheers
Mr Mac
Had it a few times as a SLF, especially in SE Asia and Mid West US in late Spring / Summer and occasionally in Europe in the same period with no issues, but I have never seen the strike like B2N2, just heard it at a distance, but A/C are designed with strikes in mind. I am more concerned with the turbulence you get associated with Thunderstorms than the lightening, which can look pretty especially at night along with St Elmo's Fire. Thanks for posting of your experience.
Cheers
Mr Mac
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From: Near SOU
A few years ago I flew from MAN to AMS with KLM. The weather was threatening but still dry.
Before we took off the pilot came on the PA as normal with the usual information and added that we might have a few bumps as we climbed due to a thunderstorm nearby. Sure enough, as we climbed there was an almighty bang and a flash from the opposite side of the aircraft (accompanied by a few screams from other pax). Things soon calmed down and the flight settled into normality again once we reached cruising height. I had a window seat on the wing and casually glanced across to the other wing. Looked at it, looked at my side's wing and looked back at the opposite wing. The winglet on the other side was no longer attached....it had gone AWOL. I sat there thinking, "someone under the climb out route from MAN had received a new garden ornament" (hoping no-one had been attacked by it).
Landed perfectly fine at AMS, everyone got off the aircraft without further issues.
The aircraft on the other hand was towed from the gate, last seen heading for the hangar....and a new winglet.
Before we took off the pilot came on the PA as normal with the usual information and added that we might have a few bumps as we climbed due to a thunderstorm nearby. Sure enough, as we climbed there was an almighty bang and a flash from the opposite side of the aircraft (accompanied by a few screams from other pax). Things soon calmed down and the flight settled into normality again once we reached cruising height. I had a window seat on the wing and casually glanced across to the other wing. Looked at it, looked at my side's wing and looked back at the opposite wing. The winglet on the other side was no longer attached....it had gone AWOL. I sat there thinking, "someone under the climb out route from MAN had received a new garden ornament" (hoping no-one had been attacked by it).
Landed perfectly fine at AMS, everyone got off the aircraft without further issues.
The aircraft on the other hand was towed from the gate, last seen heading for the hangar....and a new winglet.
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From: Everett, WA
If memory serves, on the average, every commercial aircraft will be struck about once a year. So not common, but not unexpected either. And yes, we design and test for it. The fuselage acts as a large protective cage against the 'direct effects' and so not subjected to the zillion volts that can be present in a lightning strike. Anything outside the fuselage is shielded so as to protect against the 'direct effects'.
The real risk is from the 'indirect effects' - as the lightning strike passes along the fuselage, it induces a voltage into aircraft wiring - so the avionic interfaces must have built-in protections against this potential voltage spike. Going by memory here, but I think it's calculated that the induced voltage can be as high as 100 volts, and a factor of two is applied so critical electronics must be protected to 200 volts (that's for aluminum structure, carbon composite has a higher resistance and so the induced voltages are higher - but never having worked a carbon composite aircraft I don't know the numbers).
There are also aspects you'd never think of - things like 'multiple burst'. As it was explained to me, in the initiation of a lighting bolt, it's normally not one instantaneous ark - it's a serious of very rapid (millisecond) pulses as the lightning bolt finds its way through the air before it completes the circuit and you get the 'big bang'. These rapid voltage pulses can resemble the digital 'bits' on a data bus and corrupt the data flow into an avionic box - very difficult to design for.
Not all lightning strikes are created equal - most are relatively small and don't do much. The concern is the 'big ones' - the once in the life of the fleet type - they are the ones that keep designers up at night...
All that being said, nothing is perfect - lightning has caused aircraft crashes - and there are aspects that are pretty much impossible to protect against. The shock wave from a direct lightning attachment to an engine inlet has been known to cause an engine to surge and quit. A big strike can punch a hole through structure and allow a direct attachment to something like a FADEC (not happened to the best of my knowledge, but at least theoretically possible). If the metal components inside a fuel tank are not properly bonded and grounded, it can cause a spark inside the tank (this is believed to have caused a commercial jetliner to explode and crash in the (IIRC) 1960's). There was a case in the early 2000's where there was a big, direct attachment to the nose of a 757, the electromatic effects temporarily incapacitated one of the pilots.
Shortly before I retired, I was doing a flight test on a 747-8 when we got hit by lightning. I was on the flight deck at the time observing, and there was a blinding flash and a very loud bang (although not deafening like what B2N2 described). I didn't immediately know what had just happened, but the pilots did. They had some pretty choice words for ATC - which had them doing a circling descent right in the middle of the cell...
Apparently attached to the nose and exited on the right-wing root - did some significant damage to the composite fairings that maintenance was very unhappy about (it was a pre-delivery customer aircraft)
The real risk is from the 'indirect effects' - as the lightning strike passes along the fuselage, it induces a voltage into aircraft wiring - so the avionic interfaces must have built-in protections against this potential voltage spike. Going by memory here, but I think it's calculated that the induced voltage can be as high as 100 volts, and a factor of two is applied so critical electronics must be protected to 200 volts (that's for aluminum structure, carbon composite has a higher resistance and so the induced voltages are higher - but never having worked a carbon composite aircraft I don't know the numbers).
There are also aspects you'd never think of - things like 'multiple burst'. As it was explained to me, in the initiation of a lighting bolt, it's normally not one instantaneous ark - it's a serious of very rapid (millisecond) pulses as the lightning bolt finds its way through the air before it completes the circuit and you get the 'big bang'. These rapid voltage pulses can resemble the digital 'bits' on a data bus and corrupt the data flow into an avionic box - very difficult to design for.
Not all lightning strikes are created equal - most are relatively small and don't do much. The concern is the 'big ones' - the once in the life of the fleet type - they are the ones that keep designers up at night...
All that being said, nothing is perfect - lightning has caused aircraft crashes - and there are aspects that are pretty much impossible to protect against. The shock wave from a direct lightning attachment to an engine inlet has been known to cause an engine to surge and quit. A big strike can punch a hole through structure and allow a direct attachment to something like a FADEC (not happened to the best of my knowledge, but at least theoretically possible). If the metal components inside a fuel tank are not properly bonded and grounded, it can cause a spark inside the tank (this is believed to have caused a commercial jetliner to explode and crash in the (IIRC) 1960's). There was a case in the early 2000's where there was a big, direct attachment to the nose of a 757, the electromatic effects temporarily incapacitated one of the pilots.
Shortly before I retired, I was doing a flight test on a 747-8 when we got hit by lightning. I was on the flight deck at the time observing, and there was a blinding flash and a very loud bang (although not deafening like what B2N2 described). I didn't immediately know what had just happened, but the pilots did. They had some pretty choice words for ATC - which had them doing a circling descent right in the middle of the cell...
Apparently attached to the nose and exited on the right-wing root - did some significant damage to the composite fairings that maintenance was very unhappy about (it was a pre-delivery customer aircraft)
Thought police antagonist
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From: Where I always have been...firmly in the real world
This might help as to how aircraft are protected.
It's a very basic, and NO reflection on the author, explanation about static wicks....you can also see them on the vertical stabiliser, plus, what you can't see as a pax, are the numerous bonding straps and wires attached to the structure.
How It Works - AOPA
I would agree, that, for a pax, a strike can be alarming but hopefully you are now aware of the protection an aircraft offers you in the event of a strike.
It's a very basic, and NO reflection on the author, explanation about static wicks....you can also see them on the vertical stabiliser, plus, what you can't see as a pax, are the numerous bonding straps and wires attached to the structure.
How It Works - AOPA
I would agree, that, for a pax, a strike can be alarming but hopefully you are now aware of the protection an aircraft offers you in the event of a strike.
Gnome de PPRuNe
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From: Too close to Croydon for comfort
Thread Starter
Joined: Jan 2008
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From: London
Thanks for the replies everyone…
B2N2’s account was what I’d imagine a strike to be like, but what we experienced was nowhere near that loud or scary. But I’m a fairly frequent flyer and it was a distinctly unsettling pop that I’ve not heard before. It did seem directly close to the aircraft and I’ve no reason to doubt the flight attendant’s explanation of a lightning strike.
After the initial shock, but then prompt realisation that we were still flying ok, wasn’t that scary, just made us jump!
Thanks again…
B2N2’s account was what I’d imagine a strike to be like, but what we experienced was nowhere near that loud or scary. But I’m a fairly frequent flyer and it was a distinctly unsettling pop that I’ve not heard before. It did seem directly close to the aircraft and I’ve no reason to doubt the flight attendant’s explanation of a lightning strike.
After the initial shock, but then prompt realisation that we were still flying ok, wasn’t that scary, just made us jump!
Thanks again…
PPRuNe Handmaiden
Joined: Feb 1997
Posts: 4,910
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From: Duit On Mon Dei
A former glider pilot in the village got zapped by lightning near Luton. Very lucky to survive and only suffer burns to his back. They had to bail out of the now shattered glider.
Short vid showing a successful flight but also what the lightning did.
Short vid showing a successful flight but also what the lightning did.
Joined: Jan 2007
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From: Somewhere in the 3rd world or possibly very occasionally at home.
We got hit climbing out of Sharm El Sheikh sometime in the 90s(I don't have my dive logs to hand). 737 I seem to remember.
We'd been holding on the ground due to a big storm along with several other aircraft. Eventually someone decided it was safe to go...The ground roll seemed to go on forever and we just cleared the boundary
As we were climbing out there was a big bang and a flash(It was an evening flight) but whoever was driving decided to keep going rather than go back to Sharm.
Apart from the initial shock there didn't seem to be any ill effects and we landed back at BHX normally several hours later.
We'd been holding on the ground due to a big storm along with several other aircraft. Eventually someone decided it was safe to go...The ground roll seemed to go on forever and we just cleared the boundary
As we were climbing out there was a big bang and a flash(It was an evening flight) but whoever was driving decided to keep going rather than go back to Sharm.
Apart from the initial shock there didn't seem to be any ill effects and we landed back at BHX normally several hours later.
Supercharged PPRuNer
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From: Doon the watter, a million miles from the sandpit.
I’ve experienced three lighting strikes in twenty years . Two whilst driving (funnily enough, both inbound to LHR in the BIG hold. Who says lightning never strikes in the same place twice?). Both involved a flash and muffled “phutt” sort of sound - at least in the flight deck - and had absolutely no effect on the aircraft systems (777 & 787). Thank you Mr. Boeing. The biggest hassle was that both aircraft would have been grounded afterwards for post-strike engineering inspections.
The third time was sat down the back of an A320, also inbound to LHR. There was an almighty bang and a huge flash from outside, as if we’d been lit up by the world’s biggest flashgun. Knowing what it was, I wasn’t bothered, but the cabin went extremely quiet - as in a deathly, hushed silence. One could almost hear the sighs of relief when the skipper made a soothing P.A. a minute or two later. I learned about the importance of soothing P.A.s from that…
The third time was sat down the back of an A320, also inbound to LHR. There was an almighty bang and a huge flash from outside, as if we’d been lit up by the world’s biggest flashgun. Knowing what it was, I wasn’t bothered, but the cabin went extremely quiet - as in a deathly, hushed silence. One could almost hear the sighs of relief when the skipper made a soothing P.A. a minute or two later. I learned about the importance of soothing P.A.s from that…
Joined: Feb 2002
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From: UK
I've experienced lightning strikes from the inside a couple of times. Once on an A320 we got the St Elmo's fire treatment right down the middle of the aisle, never seen anything like it before or since.
From the maintenance point of view, the damage can be hard to spot, tiny burn marks around rivets on the skin, usually tracking in a straight line from nose to tail. the exit point is often the one that shows the most damage.
When the 787 first came on the scene there was a lot of concern about how well the CFRP structure would stand up to in service life, particularly with regard to lightning.
Most of the time, treatment is very straight forward and just needs a bit of speed tape over the effected area to keep the elements out but occasionally we get a biggy and bits go missing.. There are some quite spectacular photos doing the rounds of big holes blasted in the composite structure.
From the maintenance point of view, the damage can be hard to spot, tiny burn marks around rivets on the skin, usually tracking in a straight line from nose to tail. the exit point is often the one that shows the most damage.
When the 787 first came on the scene there was a lot of concern about how well the CFRP structure would stand up to in service life, particularly with regard to lightning.
Most of the time, treatment is very straight forward and just needs a bit of speed tape over the effected area to keep the elements out but occasionally we get a biggy and bits go missing.. There are some quite spectacular photos doing the rounds of big holes blasted in the composite structure.
Paxing All Over The World
Joined: May 2001
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From: Hertfordshire, UK.
I recall reading many, many years ago - this a full metal aircraft with a single aisle. A lighting strike sent ball lightning down the aisle. I did not know whether to believe it. But if St Elmo can make it inside, perhaps it was true.
Joined: Dec 2012
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From: UK
As has been mentioned, you are basically inside a Faraday cage, so no problems for passengers. This is why all components and panels on an aircraft have to be correctly connected with all bonding leads etc attached. When a component is changed on an aircraft, or new panels fitted the fitment instructions will always include a bonding check. We use a special bonding checker to check that there is a very low resistance path between the component/panel just replaced and the rest of the airframe.
Lightning strikes have become more common in recent years, mainly because of congestion around airports meaning aircraft are quite often in a holding pattern in the kind of weather where they get struck. If a 'strike' is reported then ground engineers have to find the entry and exit points of the strike to check for damage and reprotection as necessary and anything outside the limits specified in the AMM/SRM [Aircraft Maintenance Manual/Structural Repair Manual] has to be repaired before next flight.
Lightning strikes have become more common in recent years, mainly because of congestion around airports meaning aircraft are quite often in a holding pattern in the kind of weather where they get struck. If a 'strike' is reported then ground engineers have to find the entry and exit points of the strike to check for damage and reprotection as necessary and anything outside the limits specified in the AMM/SRM [Aircraft Maintenance Manual/Structural Repair Manual] has to be repaired before next flight.
Joined: Mar 2018
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From: Central UK
Lightning strikes on a helocopter however can be much more serious. If it strikes rotor blades or tail rotor it will have to pass through a gearbox to find an escape path - which results in what is effectively a spot-weld between moving components that is instantly pulled apart. It doesn't usually cause an accident but the ensuing strip down and repairs are hideously expensive.
