View Full Version : F-18 lightning strike
NutLoose
3rd Jan 2019, 10:48
That made him jump
https://www.youtube.com/watch?v=4mbC3w-os0s
https://www.rt.com/news/447785-lightning-strike-fighter-jet/?utm_source=miximedia&utm_medium=miximedia&utm_campaign=Miximedia (https://www.rt.com/news/447785-lightning-strike-fighter-jet/?utm_source=miximedia&utm_medium=miximedia&utm_campaign=Mixi media)
Rhino power
3rd Jan 2019, 10:58
I wonder if the seat cushion was ever recovered?
-RP
Pure Pursuit
3rd Jan 2019, 16:20
I suspect that his mask is masking a few expletives there!
Chesty Morgan
4th Jan 2019, 06:59
Great reaction time, ducking after the zap :rolleyes:
OvertHawk
4th Jan 2019, 08:14
Great reaction time, ducking after the zap :rolleyes:
Did you expect him to duck before it?! :rolleyes:
I'm sure that when you fly fast jets you can see lightning coming and move out the way? :ugh:
:mad:
Bob Viking
4th Jan 2019, 08:26
What exactly do you mean by ‘you can see lightning coming’?
Are you suggesting we should have some form of superpower or am I missing something obvious?
BV
NutLoose
4th Jan 2019, 08:44
The obvious, he was being sarcastic to the reply previous.
What effect does a lightning strike have on carbon fibre composite structures, if any?
Chesty Morgan
4th Jan 2019, 09:19
Did you expect him to duck before it?! :rolleyes:
I'm sure that when you fly fast jets you can see lightning coming and move out the way? :ugh:
:mad:
There's always one.
Bob Viking
4th Jan 2019, 09:38
My sarcasm filter levels have been adjusted accordingly. 🤪
BV
West Coast
4th Jan 2019, 15:19
There's always one.
Per your tag line, it’s your turn.
Chesty Morgan
4th Jan 2019, 21:41
Per your tag line, it’s your turn.
Translation please.
West Coast
4th Jan 2019, 22:22
Translation please.Mỗi dòng thẻ của bạn, đến lượt bạn.
What effect does a lightning strike have on carbon fibre composite structures, if any?
Most aircraft carbon fiber ' structures " and panels have built in conductive ' layer' or embeded ' metallic fibers- inks- ' or similar. penetrations which may cause sparking sometimes require special care and features.
Effects other than burn marks and surface 'roughness ' are minimal and rarely structurally significant.
tdracer
4th Jan 2019, 22:41
What effect does a lightning strike have on carbon fibre composite structures, if any?
It's more likely to do damage on carbon fiber composites than on aluminum (or other metals). Carbon conducts electricity fairly well, but has a much higher electrical resistance than aluminum (about two orders of magnitude if I recall correctly). This means there is much more local heating due to the strike and hence greater potential for damage.
I don't know about the F-18, but on the 787 there is a copper wire mesh incorporated into the composite layup during build to improve the electrical resistance and hence improve it's lightning protection. I suspect they do something similar on the F-18.
Shortly before I retired, I was observing a flight test on a 767 when we took a lightning strike during our descent to Paine (i.e. Everett). I was in the flight deck observing EICAS indications for my test when it happened - it didn't literally scare the crap out of me, but it came close :uhoh:
Based on the post flight inspection, it attached near the cockpit and exited at the wing root - doing a fair amount of damage to the (composite) wing-body fairing.
I don't know about the F-18, but on the 787 there is a copper wire mesh incorporated into the composite layup during build to improve the electrical resistance and hence improve it's lightning protection.
And similar arrangement on the A-6 carbon fiber re- wings built by Boeing a few decades ago . There was/and is a lot of public available papers and research on lightning strike protection on carbon fiber structural panels and the effects. And there is also a limited amount of related published information on an virtually all fiber ' paneled ' military airplane built in the 80's - a 3 foot model of which is on a pedestal across the street from the " Red Barn " portion of the Museum of Flight :) wuztheredunthat :cool:
And although it is not me- the following link may be of help explaining
https://patents.google.com/patent/US20050213278
Pontius Navigator
5th Jan 2019, 08:03
It's the first bang that gets you. After two or three you get used to it.
Translation please.
Why do you really have to spell it out for some people?
msbbarratt
5th Jan 2019, 14:53
It's more likely to do damage on carbon fiber composites than on aluminum (or other metals). Carbon conducts electricity fairly well, but has a much higher electrical resistance than aluminum (about two orders of magnitude if I recall correctly). This means there is much more local heating due to the strike and hence greater potential for damage.
I don't know about the F-18, but on the 787 there is a copper wire mesh incorporated into the composite layup during build to improve the electrical resistance and hence improve it's lightning protection. I suspect they do something similar on the F-18.
Shortly before I retired, I was observing a flight test on a 767 when we took a lightning strike during our descent to Paine (i.e. Everett). I was in the flight deck observing EICAS indications for my test when it happened - it didn't literally scare the crap out of me, but it came close :uhoh:
Based on the post flight inspection, it attached near the cockpit and exited at the wing root - doing a fair amount of damage to the (composite) wing-body fairing.
Back when the 787 was being developed, there was a fair amount of debate as to exactly how much metal Boeing were going to have to put into this lightning protection layer. Obviously the more the put in, the heavier it was going to be, but it would be better able to deal with a lightning strike. I also recall that it had to be put in the very outer layer, so that heating of the metal layer didn't damage the structural strength of the CF itself.
Airbus's use of GLARE is quite interesting - it's still aluminium from the point of view of lightning tolerance / metal working, but it's a whole lot lighter than plain aluminium. Not a bad way to have gone about things (for the A380, which is where they used it).
On the A350 I think (corrections most welcome for my hazy memory) Airbus went for ribbons of thin metal tape wrapped around the airframe to form a sparse metal cage, instead of a fine mesh layered everywhere. I suspect that this works quite well. The lightning is going to preferentially strike / depart from sharp bits of airframe (the charge gets concentrated there), so it's probably quite easy to have sufficient metal at these points to protect any CF structure underneath.
Regardless of which approach is best, it seems that we're not having either 787s or A350s falling out of the sky or being grounded by lightning strikes. I presume that by now one or two must have got a zap.
RE major composite structures which have been flying for over two decades in commercial this may 2004 article may help
https://www.boeing.com/news/frontiers/archive/2004/may/i_ca3.html
In 1992, Boeing opened the state-of-the-art facility to provide composites solutions for the Boeing 777 empennage, which is made up of the vertical fin and horizontal stabilizer. Now just over a decade later, Structural Composites Frederickson is getting ready to celebrate the milestone delivery of its 500th 777 empennage.Part of the Fabrication Division for Boeing Commercial Airplanes, Structural Composites Frederickson today is focusing its manufacturing excellence for primary and secondary composite wing-like structures on a new dream: the Boeing 7E7 Dreamliner.
clark y
6th Jan 2019, 19:43
I'm impressed by the burn mark along the RH side of the canopy. I can only assume it is made of acrylic or similar.
Pontius,
I remember my first lightning strike quite well. It was in an A320. Lightning hit just out the front. I jumped, the jump seat traveller jumped. The very experienced RH seater training captain just stated in a quiet voice "it's going to be a long night".
1986, PD to Wattisham with USAF exchange driver in the front of our 228 OCU F4. Crap Wx, lightning strike on downwind leg for a GCA. Me having kittens in the boot; driver says "Plenty o' them in 'Nam". I wound my neck in in respectful awe....
WhatsaLizad?
8th Jan 2019, 03:25
Shortly before I retired, I was observing a flight test on a 767 when we took a lightning strike during our descent to Paine (i.e. Everett). I was in the flight deck observing EICAS indications for my test when it happened - it didn't literally scare the crap out of me, but it came close :uhoh:
Based on the post flight inspection, it attached near the cockpit and exited at the wing root - doing a fair amount of damage to the (composite) wing-body fairing.
TD,
We took a strike after T.O. in IMC flying a 767-300 a few years ago. I'd swear from the flash and the boom, like a .45 Cal discharged in the cockpit, and that it hit the wipers 3' in front of our faces.
Immediate post strike actions were to fly and assess any damage. I then announce we lost VHF with departure control and to try the #2 VHF.
Fortunately, I was flying with a very observant FO who said, "CA, you flinched and hit the VHF TXFR switch, switch it back to Departure control.".
Emergency over, I reaffirmed my command authority by calling for the After Takeoff/Climb Checklist. :p