You do when you're being refueled, but that's to protect the bowser as much as the plane.

I seem to recall reading the USAF lost a few aircraft for this reason in the early 90s, ended up changing their fuel mixture as a result.

Ground power also earths the aircraft IIRC

I have seen a 10 metre telegraph pole after being struck . Nothing much bigger than a matchstick remaining,spread over a 15 metre radius and a 2 metre hole in the ground. Lot of energy to do that.

A few strategically placed lightning masts will suffice: https://en.wikipedia.org/wiki/Lightning_rod#Standards

Normally several "risers" of charge ascend, at the same time the main charge descends , or several threads of charge coalesce and descend. One lucky riser gets to meet the charge coming down first, and so gets the full current. The "Lightning strikes" that don't do much damage or that people walk away from I am pretty sure are un-fulfilled risers. Getting the main discharge is so much energy it's not going to just burn your bum.
A dirty great alloy fin (tailplane) sticking the air is a good start to a riser (much like a lightning rod). Given the plane is wearing rubber shoes, I too am not sure of the wisdom of connecting the (anti static) earth with a storm overhead. It certainly wouldn't be me connecting it.
Maybe some meteorologist will be along with the full sp shortly.

I think we are all agreed grounding (arching) the aircraft will not protect against lightning. However, aircraft plugged into ground power provided by motor/generators can provide a big surprise. One graveyard shift where most weird things happened, we noticed a long tongue of fire erupt from the ground wire connected to the nose gear of an L-1049 Connie. It was the accumulated oil burning off then insulated ground cable. The aircraft was on the fence plugged into a 28V DC motor/generator powered by 3ph 440V. AC. Insulation had failed allowing one leg to connect to the neutral leg of the 28V DC power. A/C was happy, it couldn't see it. Ground wire did.
Power cables also can have faults. I personally think ground iris are. Good idea.

Did I see something knocked off the plane in that video?

As SMT Member said - Bluetooth. The ones used at HKG are these:

3M? Peltor? Bluetooth Ground Mechanic Hi Viz Headband headset | £197.00 | MT53H7AWS2-01 GB

The way earthing works is it reduces the potential of the earthed item, or more exactly equalises any potential making the earthed item 'less visible' to an atmospheric charge. A good example of this is a yacht. My boat has a 45ft metal mast which you would think would be a massive lightning magnet - particularly in the waters around Hong Kong where it usually sails. However, the mast is earthed to the cast iron and lead keel by a 2" wide copper earth strap which from experience, works very well. Once, we had a lightning strike so close to the boat we could see the seawater boiling - but it didn't strike the mast. In the bay which it is moored, there are about 15 mono-hulls with keels and 5 catamarans - which don't have keels. The cats get struck regularly, but with the mono-hulls, it's very rare.

At HKG, the earthing of aircraft is mandatory.

I thought all ramp activity is supposed to stop when lightning is within 5 miles? This doesn't look like a so-called "bolt from the blue"

About 20 years ago in Sydney, a teen aged boy was killed by lightning whilst batting in a cricket match. At the time there was clear blue sky overhead and a storm was brewing about 20km away. The lightning was powerful enough to turn a solid cricket bat into toothpicks.

I have read that lightning can strike up to 10 miles ahead of the storm. So you can have clear sky overhead & be at risk. Saw a strike in my neighbour's yard over the back fence while I was racing to finish mowing the lawns with a storm about 8 miles away at best guess. Needless to say, I packed up PDQ & the lawn waited until another day!

The lightning was quite small, like a piece of cord or small diameter rope & there was no thunder associated with it. I understood then how people get struck & seriously injured or killed while on golf courses or beaches with clear sky's above them & the nearest storm miles away. Personally I think 5 miles is not enough & aprons should be cleared when an approaching storm is 10 miles away.

It might not, but I'd sure as hell rather be standing next to a well-earthed aircraft than a non-earthed aircraft if the lightning ever should unexpectedly strike.

I still might cop a belt, but if the earth cable takes some of the belt, that's less of a belt for me!

Dan's notion is about risers that trigger the main blast. However, I'm of the opinion, that if you want to protect the aircraft you should let it's potential difference, p.d., relative to ground, float to where it wants to go. While fields are building up, the whole (bonded) aircraft will become nearer to the offending field's potential and therefore have less attractive force.

Here, we're only talking about spray which causes sparkling discharges. A main bolt is quite a different matter.*

Two problems: one is if Dan's assertions are correct then there would be less of a chance of a strike in the first place. I put the question on a physics forum but there has been almost no response so far.

The other problem with the aircraft's p.d. floating is that if some luckless soul had one foot on the last step of some airstairs, and one on perhaps damp ground, he'll get the most serious case of nut-illumination imaginable. So, for ground crew protection the aircraft must be grounded.

*The entire exercise is about light spray of fields. A serious bolt of lightning is physics at is most ferocious. The voltage sheer across the area outside the plasma core can be a million volts per inch. Any notion that being 'static electricity' will be helpful you can forget. The currents in that core are capable of boiling metal.

Mindful of history. Flying a kite with a wire string is not the wisest of ideas.


Back to the aircraft. The only way I see to truly protect a very high tail is to have a dedicated Cherry Picker stationed right by it with a specialised rod pointing skyward. It would have to be seriously well grounded. Trouble is, you'd need one for every aircraft, though perhaps protecting a high value A380 just might give an umbrella of protection for smaller ones nearby.

Thick copper conductors for masts and churches seem to work well for minor discharges, but I suspect it is the ridding of those pre-charges that does the magic. Lightning conductors can be vaporised.

The way it tends to work is that at any point in its travel, the lightning bolt will pick the easiest route to ground. Your big danger is that if you're close to the aircraft, it might determine that the easiest route is to jump the air gap between aircraft and you, then go to ground via your feet. The big, friendly ground cable is an attempt to encourage it to follow a known and predictable path.

The biggest danger when near a strike is the ground current as it disperses. The resistance of the earth may mean that two points a metre apart have a 5000V potential difference. This is less of an issue for humans because our feet tend to be a lot closer together, but it takes out a lot of cows if they're in a field and there's a nearby lightning strike.

An earth for a lightning protector doesn't have to be just a stake in the ground. For buildings they are sometimes an underground mesh or ring around the building to help dissipate the charge so as not to cause damage to building foundations.

What I've noticed is that the easiest path to ground is usually someone touching (or wearing a headset attached to) an aircraft. Surely an earth cable would help, given the only other path to ground is through thick rubber tyres.

Correct.

Known in the HV electricity trade as 'step-and-touch' potential. That's why HV substations have a buried earth grid round them. The fault currents, if something goes wrong even on a feeder outside the substation, can be of the order of 10s of kA. And if the earth resistivity is high that can give you a nasty jolt. Just from opening a metal gate or touching the fence. The buried grid evens out voltage differences over a wider area.

Bear in mind any AC voltage above say 65V or so can kill. That's why hand tools should always be fed from a centre-tapped (and earthed) 110V supply. Max 55V to earth. Deemed safe

We took 45 minute delay in MXP few days ago due TS

This is what it’s like to be struck by lightning – mosaicscience.com

Fascinating thread, thanks to all who've contributed. Sad to read about some of those affected and it seems some airports are better than others at protecting their workers ( and passengers!).

Not entirely reassuring as someone who lives in the tropics and occasionally finds myself outside as nature unleashes its fury! When the lightning and thunder start occurring near simultaneously and there's nowhere to duck into it's not a particularly comfortable place to be. Also quite alarming reading about numerous strikes when there was no rain around. I know the odds are low but a friend's sister was actually killed by a strike so I guess that makes me more hyper aware.

Earthing will increase the chance of your boat sending up a streamer. The reason for grounding is to give the lightning a low resistance path to discharge, to reduce the chance of it dispersing all over your boat and turning you into a human sparkler.

As a child, I was in a house in the Alps when it was struck by lightning. My sister was sat two feet away from an electrical socket at the time. A side flash came out of the socket and electrocuted her. Fortunately, no permanent injury was caused to her.

Back to the original post, the victim's father posted this publicly on Facebook:

https://www.facebook.com/kyle.dunn.7...00556240050837