Lightning is a scary-miraculous phenomenon we admire, we would like to know more about, we take photos of, but we are afraid of it, too. Physicists have been studying this phenomenon intensively for hundreds of years and still we do not know everything about it.
There are controversial opinions if planes are safe in lightning or not.
Pro (it is harmless)
Some say that a plane – just like a car is a Faraday cage, therefore it cannot be harmed by the external electric shock. But what is a faradya cage? According to the definition of Wikipedia a Faraday cage or Faraday shield is an enclosure formed by conducting material, or by a mesh of such material. Such an enclosure blocks out external static electrical fields. Faraday cages are named after physicist Michael Faraday, who built one in 1836. An external static electrical field will cause the electrical charges within the conducting material to redistribute themselves so as to cancel the field’s effects in the cage’s interior. This effect is used, for example, to protect electronic equipment from lightning strikes and other electrostatic discharges.
Apparently by the laws of physics planes could not be hurt by lightning. So why is it that still airospace control keeps all planes away from areas hit by heavy rainstorm and thunderbolt?
It is not just lightning that can affect a plane in a heavy strom. Lightning itself indicates huge energy, therefore it has dynamical effects as well. So besides tough turbulence caused by strong wind in stormy circumstances, lightning can also shake the plane heavily by hitting it. We took a look at the background of different accidents and it turned out that one of the main causes when a plane crashed following lightning was turbulance that smashed the planes to the ground.
Contra (it is harmful)
Some other physicists say that even though it is a Faraday cage, it is not perfect, because there are antennas for external communication like navigation, radio, etc. These antennas behave as holes on the shield and although lightening still cannot harm any passengers or interior of the aircraft, but the antennas lead this high voltage electricity into the electronic equipment of the aircraft, thus they can harm navigation, computer or electric wiring.
Among the accidents we could see a plane that cought fire following a lightning stroke in and it ignited flammable fuel vapours around the engine, which seems to be another risk factor.
Also some say that a metal object in the middle of a strom even attracts lightning, so planes are at special risk.
Result
After all these I prefer saying it is better to avoid stormy weather, but it is not necessarily lethal flying among thunderbolt and lightning, so once you travel and experience that, you do not have to panic. On the other hand the new generation of aircrafts will be made of carbon fibre plastic that does not conduct electricity as metal does, so it will be even less dangerous. Finally we collected some accidents caused by lightning as a critical factor. They all talk for themselves, it is worth to read them through.
Highlights from Aviation Safety Netwrok’s statistics
Dornier 228-202 – Dec, 2003
Kato Air flight 603 departed Røst at 08:23 for a domestic flight to Bodø. A severe thunderstorm was passing over the Bodø area with severe winds gusting up to 40-55 knots as the flight approached the destination. At 08:52 the pilot reported that they had been hit by lightning. Apparently, rudder control was impossible due to damage caused by the lightning strike. Using engine power and elevator trim, the crew attempted to land at 08:58. This had to be aborted, so the plane circled for another attempt. On the second attempt to land, the airplane smashed onto runway 25, causing the undercarriage to collapse. The airplane sustained severe damage to the underside of the fuselage and the center part of the main fuselage was buckled. Luckily everybody survived the accident.
Merlin IV – Oct, 2001
The Spanish accident investigation commission CIAIAC concluded that the Merlin IV that crashed in the Mediterranean in October 2001 killing 10, was probably caused by a lightning strike. The aircraft was on route from Barcelona, Spain to Oran, Algeria, when it encountered a powerful electrical storm with associated rain and turbulence. The lightning strike probably caused the failure of the electrical system after which the airplane lost control.
Lockheed L-1011 Tristar 1 – Aug, 1985
Reason of crash: the flight crew’s decision to initiate and continue the approach into a cumulonimbus cloud which they observed to contain visible lightning; the lack of specific guidelines, procedures and training for avoiding and escaping from low-level windshear; and the lack of definitive, real-time windshear hazard information. This resulted in the aircraft’s encounter at low altitude with a microburst-induced, severe windshear from a rapidly developing thunderstorm located on the final approach course. 134 were killed on board and 1 on the ground. You can read the conversation of the pilots recovered from the blac box here.
Boeing 707-121 – Dec, 1963
Pan American Flight 214 departed San Juan, Puerto Rico at 16:10 EST for a flight to Philadelphia with an intermediate stop at Baltimore. The aircraft, named ‘Clipper Tradewind’ arrived at Baltimore at 19:35 and took off again after refueling at 20:24. After contacting Philadelphia Approach Control the crew elected to wait in a holding pattern along with 5 other aircraft because of extreme winds at Philadelphia. Flight 214 entered a holding pattern west of the New Castle VOR on the 270 radial.
At 20:58 Clipper Tradewind suffered a lightning strike. This caused the initial ignition of flammable fuel vapours inside the left reserve fuel tank. This triggered explosions in the centre and right reserve fuel tanks as well. Fuel spilled and caught fire; the complete left wingtip separated as a result. The aircraft was then seen to crash in flames. A ‘Mayday’ call was received by Philadelphia Approach as the plane was descending out of control.
Handley Page Hastings – March, 1960
The Hastings departed RAF Katunayake at 17:34 for a flight over the Indian Ocean to RAF Gan in the Maldives. Weather near Gan was poor with heavy rain and thunderstorm. The first approach was abandoned and the pilot decided to hold for 20 minutes, hoping the storm would pass. During the second approach a lightning flash blinded the pilots, during which the aircraft descended to a height just above the sea. The aircraft then hit the sea and crashed. Investigations found that the pilot missed some actions to avoid the accident.
Airline world 
I was a passenger aboard a flight from Stansted (London) to Antalya (Turkey)on March 12th 2008. I preface this note with the statement that I am not a nervous flyer, I am a business flyer who travels in excess of 50 flights per year and have done so for the past 20 years. During this time, I have experienced a variety of phenomenon associated with flying as a passenger on scheduled and charter flights. Its also worth saying that I’m no armchair pilot either.
The aircraft we flew in that day was a Boeing 737 series 800 aircraft. I was seated in seat 29F
We departed from Stansted late.
When we commenced our descent for landing at Antalya the flight was perfectly normal.
As we started to descend into Antalya bright lightning flashes were visible and hammer heads of nearby clouds were easily seen in the flashes.
The descent continued and pretty soon we found ourselves on finals in the midst of a particularly violent electrical storm.I guess we were about 1500 feet high at this stage. The aircraft was pitched about violently. Significantly more so than I have ever experienced in over 20 years of flying as a commercial passenger. There were both significant and violent falls and increases in height, airspeed and direction. Heaviness and lightness sensations in the seat like I have never experienced before The flight crew continued their approach notwithstanding the increased tempo of the storm.
By this stage passengers throughout the aircraft were screaming. Many around me were vomiting. Almost all were clearly scared. As indeed was I. The overwhelming smell in the cabin was of vomit and excreta. Overhead lockers started popping open and baggage rained down.
The approach continued and the aircraft continued to buck and started to roll to the right accompanied by screaming engines et al. This was the point when I believe we were hit by lightning strike
We were much lower by this stage – I guess no more than 250-500 feet. At one stage I looked down on street lights and cars at a height whereby details of the cars below (ie the occupants were visible to me). The aircraft wings seemed to be at 180 degrees to the ground at this stage. Lightning and heavy rain were constant and the aircraft was evidently being buffeted by severe winds of a vertical as well as horizontal direction. The fuselage was bucking in both vertical and horizontal planes. the movement was sufficient to throw a passenger in an aisle seat in my row from his seat into the aisle.
To cap it all – at this stage the cabin crew immediately behind me were saying prayers!
I could see that vertical movement of the wings was constant and it was self evident that we stood no chance of a successful landing in such conditions. Finally we pulled away and started to climb – rapidly. Our route however took us into even greater turbulent air and lightening bolts.
The person flying the aircraft made 2 attempts to land in these appalling conditions and luckily avoided catastrophe before finally deciding to abandon his attempts and fly his now terrified passengers to Ercan in Northern Cyprus.
On arrival at Ercan, many passengers were so scared that they were unable to stand. Many were visibly shaking and very distressed. When I left the aircraft via the front entrance, my route took me along a path of seats and cabin carpet badly soiled with vomit and excreta.
Even now I am amazed by flight deck behavior (which given the information available to those flying the aircraft at the time)that placed the safety of the aircraft and its passengers and crew at a completely unnecessary risk.
The fact that the ill advised attempts to land were abandoned and the flight diverted to its ultimate destination of Ercan, merely reinforces me in this belief.
Aircraft are fitted with sophisticated radar equipment capable of identifying and avoiding such risks. Supplemental information would have been available from the ground.
In simple terms, this was the most horrific flight I have ever endured. In my humble opinion maybe lightning alone can’t bring a plane down. However, from my own experience it is clear that lightning, thunderstorms, heavy rain and other forms of bad weather combined with perhaps the most minor of mechanical difficulties most certainly could.
For what its worth, (and its not much,) my own thanks go to the design engineers and the guys on the shopfloor at the Boeing Aircraft Corporation. Looking back I was amazed that any structure could withstand what was thrown at us that evening. Our survival was due to those guys at Boeing rather than the idiots flying the plane.
Lightning can not bring down a plane. Period. There’s no grounding so it cannot be damaged by a strike. The reason that airplanes are routed around thunderstorms is that the thunderstorms contain air currents which are extremely unpredictable. There are two common mechanisms which are known to bring down airplanes in a thunderstorm: wind-shear, which is what the previous post described so very graphically, and a loss of lift due to a loss of relative airspeed. Wind-shear is basically an immensely powerful downdraft which will cause a plane to lose altitude very rapidly. If they are too close to the ground when they fly into the downdraft, they crash, plain and simple. The other happens when the plane encounters a hideously strong tailwind. Notice how planes don’t fly backward? That’s because lift is only produced in a large enough proportion to maintain flight if the wings maintain a high velocity forward compared to the air around them. If you encounter a tailwind strong enough, all relative forward velocity is lost, and the plane stalls. If it is too close to the ground to recover, then people die. It is never because lightning struck the aircraft (unless the pilot had a heart attack from being scared by the noise).
Very rarely.
Since the outer skin of most airplanes is primarily aluminum, which is a very good conductor of electricity; the secret to safe lightning hits is to allow the current to flow through the skin from the point of impact to some other point without interruption or diversion to the interior of the aircraft.
Estimates show that each commercial airliner averages one lighting hit per year but the last crash that was attributed to lightning was in 1967 when the fuel tank exploded, causing the plane to crash. Generally, the first contact with lightning is at an extremity…the nose or a wingtip. As the plane continues to fly through the areas of opposite charges, the lightning transits through the aircraft skin and exits through another extremity point, frequently the tail (as shown by Gauss’s Law).
Another related problem with lightning is the effect it can have on computers and flight instruments. Shielding and surge suppressors insure that electrical transients do not threaten the on board avionics and the miles of electrical wiring found in modern aircraft. All components that are vital to the safe operation of commercial aircraft must be certified to meet the stringent regulations of the FAA for planes flying into the United States.
Aircraft, and by that I mean the body of the aircraft and not the occupants inside, are protected from lightning strikes by two things. The first and most important of these is the brains of the pilot and the weathermen who predict where violent storms are likely to be. The second is through a small unsung device called the “static wick”.
For more details see my source.
http://www.physlink.com/Education/AskExperts/ae568.cfm
I also was struck by lightning in a Dornier 228. Did lots of damage to elevator. Would like to share story and picture.