Is it possible for an airplane in flight to be struck by lightning?

[wa2dtw]

One of the theories of what might have happened in the tragic loss of the Air France plane flying from Brazil is that it was struck by lightning.

Grounding has always been a spooky and complicated issue for me.   But according to what I understand about it, lightning should seek an earthly target and not a flying plane.   I always thought that planes in flights (and cars on the road, because of insulation from the tires) were immune to lightning.

Is this not so?

[W7SOE]

Airplanes get struck by lightning all the time and are built to handle it.

Rich

[wa2dtw]

But I don't understand how this can happen, unless the plane by chance flies into a lighhning bolt that was occuring anyway?   Presumably, the plane is not at ground potential?

[Steve - WB3HUZ]

An object does not need to be at ground potential to be struck by lightning. There is more cloud-to-cloud lightning than cloud-to-ground. Only a difference of potential is required.

[wb1aij]

The airplane is not at the end of the lightning bolt but merely a small length of its path. Since it a good conductor of electricity a bolt that is passing in the vicinity might use the airframe as the path of least resistance. There is some concern about the new airplanes using composite materials for the skin; if it is not a good conductor the bolt will create mucho heat as it passes through & could cause mucho damage if there are no provisions to conduct the current through a low resistance path. I think Frank, WA1GFZ, works with this stuff at Hamilton Sundstrand. He might have a better answer for you.

[DMOD]

Generally speaking, a metallic aircraft can get hit by lightning but the bolt will continue on since the aircraft will be at nearly the same potential as it's surrounding. Composite aircraft usually have a buried mesh in one of the layers of composite to carry currents throughout the body and act as a Faraday cage.

Somehwere on youtube there is a picture of an Airbus A320 or such getting hit by a cloud-to-ground lightning bolt and continuing on without incident.

If the aircraft was flying through or near a thunderstorm, I would suspect either air turbulence or hail damage as the more probable cause. The leading edge of a large storm has rain shaft downdrafts and microbursts which would gust the plane downwards and make it lose altitude. In the trailing edge of the storm and near hail cores there are strong updrafts, and hail the size of grapefruit can go right through a wing causing loss of control.

Most pilots watch their weather radar and try to fly around such storms.

Phil - AC0OB

[WD8BIL]

You mean this?

[Jeff W9GY]

I was flying in a Convair 440 in the 60's that was struck by lightning (the pilot came on the intercom and so). I remember a very bright flash, and instantaenous sound occuring.  Scared the hell out of the stewardess  (sorry, "flight attendant", in today's lingo).

One of those situations where the airframe became part of the path.

[W1RKW]

granted these are 2 different vehicles and situations but Apollo 12 was struck 2 times during liftoff. Below is what apparently occurred after each strike:

http://www.aerospaceweb.org/question/spacecraft/q0140.shtml

[DMOD]

That's picture I was referring to BIL.

I took off in a DC-9 from Chitown's Midway Apt. one night in a rainstorm and multiple lightning strikes hit the plane as we were ascending. Most appeared to eminate from an upper cloud, hit near the outer wing, and went on to the ground, lighting up the ground. All we felt was a light shudder during each strike.

After we got to cruise altitude and pointed toward St.Louis, we were told a tornado had hit North Chicago as we were taking off. 

All of this happend AFTER the engines stalled on the ground from rain ingestion, and had to be restarted.

[W7SOE]

It is my understanding that an airplane will develop its own charge due to friction with the air.  Next time you fly, look at the trailing edge of the wings.  You will notice small rods that look like stiff strings sticking off the back.  These are "static wicks" to bleed off charge.

Helicopters also develop charge, see:

http://www.youtube.com/watch?v=_cx-eOUjNPE&feature=PlayList&p=B87BF397886FA323&playnext=1&playnext_from=PL&index=68

Rich

[Ed/KB1HYS]

A young man was makeing a hook up to a UH-1 for sling loading. The object that he was hooking up was a rubber fuel blivot.  He didn't wait for the other guy with the big ground rod to hit the choppers hook first.  When he made the hookup the static shock launched him off the blivot and several feet away...

[WB3JOK]

I always thought that planes in flights (and cars on the road, because of insulation from the tires) were immune to lightning.

Is this not so?

Cars on the road are relatively "immune" because of the same Faraday cage effect already mentioned. Doesn't mean you won't be turned into a deaf albino with brown pants, at least temporarily.

However - if the potential difference is great enough to ionize five to ten thousand feet of air, I don't think the six inches of rubber between the rim and earth will present much additional barrier to flashover 

[VE3GZB]

W7SOE nailed it.

[Bill, KD0HG]

Maybe 20 years ago I was driving a 1976 Blazer across a northern Arizona highway when a storm rolled by.

Lightning was hitting everything around. powerlines, piles of rock along the road. My truck was the highest object around and nothing to duck under.

Nearby hits smoked my CB rig on a 102" whip antenna and wrecked my cassette deck.

It was truly frightening.

Fortunately, no onboard computers, a carburetor and an old fashioned Kettering ignition system.

[WA3VJB]

I want to know more about the automated communications this incident triggered, since a lightning strike would probably register among the sensors whose outputs were streamed.

According to what airline and government officials have said, the aircraft sent several minutes of telemetry to the ground-based Air France computer system. So far, details are vague as to what systems were interrogated or assessed in this datastream, but I'll bet voltage transients are among the readouts.

Cabin depressurization is one of the few mentioned specifically, alongside characterizations that the telemetry indicates something catastrophic was underway.

As of this morning, no mechanical or electronic pings have been detected from the on-board cockpit voice recorder or flight systems data recorder.  Despite chronic misreporting by the media, they're not "black boxes," by the way, but rather are day-glo orange to aid in recovery.

[K3ZS]

It is my understanding that an airplane will develop its own charge due to friction with the air.  Next time you fly, look at the trailing edge of the wings.  You will notice small rods that look like stiff strings sticking off the back.  These are "static wicks" to bleed off charge.

Helicopters also develop charge, see:

http://www.youtube.com/watch?v=_cx-eOUjNPE&feature=PlayList&p=B87BF397886FA323&playnext=1&playnext_from=PL&index=68

Rich
I can confirm this.
Where I worked, we had an Aero Commander 680 that I used to fly in every once in a while.   One time, under IFR conditions and flying in the clouds, I touched the plastic windshield and got quite a jolt.

[W3RSW]

When a plane flies into the belly of a UFO, all auto-reporting systems on a modern plane are triggered into the 'tell' mode, but only during the transition phase before being totally absorbed or transported to other realms.   (reference "DUQ") 

My other (more realisitc? heh, heh) theory is that since O₂ lines were deployed along with other cabin depressuring alarms is that the plane was sabatoged, very effectively by explosion in the cocpit.  Be interesting to see the wiring diagrams/logic reporting trail of the A220.

[WA1GFZ]

Our Lightning expert is at a Meeting so won't see him till next week. He may have some news by then. Weird that the whole plane went out. tanks are charged with nitrogen these days after that 747 blew up.

[Tom WA3KLR]

The news says that there is a 35 mile spread on the debris.  A question to the ocean-experienced people - is this spread reasonable for a day after a crash landing at sea, or is this much more indicative of a break-up at high altitude?

[KA1ZGC]

Lightning strikes aircraft all the time. It's never been an issue before now, because aircraft have had a metal fuselage. A metal fuselage is a Faraday cage, lightning strikes merely conduct through it and out the other side. The instruments inside usually don't suffer permanent damage. Lightning strikes have been considered routine occurances as a result.

Newer-generation aircraft are being built with composite fuselages. A composite fuselage offers no such protection for the on-board instrumentation, passengers, or crew.

Flying one of these planes manually is not an option. In this day and age, there is seldom a direct mechanical or hydraulic connection from the yoke and pedals to the control surfaces. The vast majority of aircraft have some kind of microprocessor assistance on these systems. Fry that, and you can't fly the plane anymore.

Even if that doesn't fail (or even if you do have direct hydraulic control), you only need to lose your altimeter and artificial horizon in a thunderstorm to lose all sense of up and down. They may have thought they were holding the nose level when in fact they were diving into the ocean.

They may have lost their hydraulic pumps. All the instruments could have been functioning in that case, and all they would be able to do is watch in horror and decide whether or not to tell the passengers that they're all about to die.

So hit a composite-fuselage aircraft with lightning, it's going down on way or another. They may save a boatload on aircraft cost, but the result is a boatload of plane wreckage and corpses. Lightning strikes go from "routine" to "fatal".

It's my understanding that this was a very new aircraft. If it was a composite-fuselage type, my money is on a lightning strike bringing it down. What the lightning damaged won't even matter at that point, the cause of death will still be "flying in a non-metallic aircraft".

[W3RSW]

..well they did find debris so I guess it wasn't abducted after all, unless the aliens are very crafty and did a "U boat" torpedo tube, oil dump for effect. 

My understanding is that the A220 was a 2005 model and similar if not exact same plane had been hit by lightning before with no ill effects.   Saw a video via Drudge on that.   Apparently the plane had been 'understrung' with sufficient mesh or wire to conduct charges.

Perhaps is was just the 'perfect storm' and the wings sheared under repeated, constant stress in the very severe equatorial storm belt which I understand is much stronger and spatially extended than those we see over continental US.

[Steve - WB3HUZ]

Or maybe the U.S. Military shot it down.

[W1RKW]

Or maybe it was hit by a bunch of big ass hail stones if it was flying into a thunderhead.

I can't imagine all systems on board an aircraft being disabled by lightning. We all know how lightning hits certain things and avoids other things.   If the Airbus, like other fly by wire systems has redundant systems there's always the possibility of maintaining control but again unless it flew into a hail storm of huge hail no system would survive that.  My guess it was piss beat by hail, depressurised, crew lost consciousness, control and succumbed. If not, it was sabotage. It's possible that maybe lightning took out the fuel system??? 

The forensics will be interesting if any conclusion can be made from what ever is collected. This will probably be one of the most complex flight investigations yet.

[Sam KS2AM]

http://momento24.com/en/2009/05/27/bomb-threat-on-air-france-flight/