Air France: Missing jet possibly hit by lightning

[aris]

This just terrible..


http://www.msnbc.msn.com/id/31040692/?GT1=43001

[ZeroChalk]

just horrible.. we've been talking about it at work.

[sicsol]

I have cargo on this flight, well my company does. This is not the first time for Air France, everyone remembers Air France crash at PIA

[FoXy]

Still really sad tho.

[STeeLy]

really sad indeed!!! I hope they find something...

[marvin24k]

indeed It's sad, but it's actually a miracle this doesn't happen more often...

Every time there's a sudden thunderstorm near Pearson, I step out on my balcony to see the airplanes pull up to abort landing. It's crazy the amount of force airplanes have and can withstand.

[Fobio]

apparently lightning strikes planes ALL THE TIME. for a plane to malfunction due to a lightning strike is rare...


Question

How is a plane protected from Lightning strikes?

Asked by: Sridhar Narayanan

Answer

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.

Answered by: Rich Uranis, B.S., University of Michigan, Ann Arbor


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".

Most aircraft do not fly into lightning storms, or fly through storms or areas where lightning is likely to be present. What we see as lightning is really a massive flood of electrons seeking equilibrium, either from cloud-cloud or from cloud-ground. In both cases, huge amounts of electric charge build up at the edges of the cloud. The electricity finds it's way from one place to the other via what's called a "step leader".

The sheer power of the cloud will start to attract electrons from the ground. These electrons will gather on anything that gathers charge (like a fence) or sticks up in the air (like a person), or that does both (like a telephone pole). That electric charge will start to work it's way through the air, ionizing it, until the leader working it's way down, and the leader trying to get up finally meet. When they do - there's lightning. An aircraft flying between the highly charged portions of a cloud will act as a conduit for step leaders, being able to produce one in each direction. If either of them meets a leader coming the other way... ZAP.

The way an aircraft tries to dissipate these step leaders is through the use of something called a "static wick". A static wick is a piece of metal connected electrically to the frame of the aircraft, with one or two spikes or needles on the end. It is housed in a fiberglass rod to insulate it from the airplane. Because the spikes concentrate the electric charge around them, and they are connected to the airframe, they allow the airplane to dissipate any static electricity it may build up out into the air. Also - if lightning DOES strike the plane, the chances are that the electricity will go through the dissipator and not through the airplane. You can see pictures of these dissipators on the 737 webpage below.

So, when discussing how an airplane is protected from a lightning strike, the best safety feature is the pilot who checks the weather before he flies and makes smart decisions about where to fly. If the plane is forced to fly through a storm, the static wicks on the wing's trailing edges should help keep the plane safe.

[crystal8484]

Jacob wanted them on the island...

[-cj-]

I was just going to mention what Fobio posted... I saw something on TV show that said that planes get hit all the time and that it just travels through them... So it's normal. I mean, it would be stupid to design something that's going to travel through the clouds and not prepare for lightning strikes. :/

[Flagrum_3]

Lightning can cause damage in rare occasions, as in slight burnt skin panels or in some cases small electrical failures, such as relays etc; ...not anything that would bring a large aircraft down.

But it has been reported that Airbus received a Data-link from this flight just minutes before it dissappeared, showing an electrical failure of some kind.

It is also reported; it has crashed somewhere in the ocean and the probabilty of survivors is nill......very sad loss of life.


_3

[-cj-]

Yeah I was reading about the automated messages being sent back.. That's so awesome. I bet it's only a matter of time before they just send the blackbox data somewhere in real time and only archive it locally for redundancy.

But yeah, their odds don't sound very high. :/

[Fobio]

Just want to clarify the significance of an auto signal:

Planes are basically in constant radio contact with air traffic control and other aviation radar system. This flight didn't even have a last communication...so the auto signal was the last communication, which comes online after the major systems of the aircraft has failed...so to me, this means by the time the auto-signal was transmitted, the plane has already succumbed to critical damage... =(

Here's a quote from today's Star:

http://www.thestar.com/news/world/article/644020


The French government minister overseeing transportation, Jean-Louis Borloo, said officials "do not believe that a simple bolt of lightning, something relatively classic in aviation, could have caused the loss of the craft."

"There really had to be a succession of extraordinary events to be able to explain this situation," Borloo said on RTL radio Tuesday.

[RallyPlaya]

I am Really interested in seeing the conclusive evidence of what caused this tradgedy, can't blame the Bermuda Triangle on this one...Its truly a sad catostrophe...I was wastching coverage on the BBC last night and they indicated that the plane didnt give off a mayday signigifying thay whathvere occured it happened fast and the pilot had little response time

[Fobio]

For those interested, here's a meteorological analysis:

http://www.weathergraphics.com/tim/af447/

WARNING: it's a LONG read.

[STeeLy]

TAM flight pilot flying over the area spotted what looks like fire on the atlantic ocean after the plane cleared the storm.

CNN says there are flying debris on the ocean with seats and such.

[sicsol]

Airplane Seat, Life Jacket, Among Debris Found Near Likely Downed Jet: Brazil Air Force

Tuesday June 2, 2009
CityNews.ca Staff

[Thrizzl3]

thats soo sad :(

[qycxzerqp]

I just knew, 228 all died. RIP to all those ppl.

[sp3GT]

Very sad, just had a read through another article. They believe the plan disintegrated before hitting the ocean.

[mazdabetty]

I watched a clip on the news last night interviewing a passenger's wife, I wanted to bawl my eyes out when she said "I hope he wasn't frightened" :(

[Fobio]

this incident is horrible because:

1. ppl think planes go down becuase of lightning.
2. no blackbox yet, just a whole lot of speculations.
3. unconfirmed news stories of last minute cell phone calls to and from the plane.
4. no conclusive report to alleviate ppl's concerns.

it is impreative that they retrieve those black boxes...228 ppl dying is bad enough, if we don't find out what happened, then they'd have died in vain. finding the black boxes could potentially save thousands of lives in the future. furthermore, considering current economic conditions, the airline industry can not afford to have an unexplained mid-air incident...ppl will stop flying, Air France will eat it, along with Airbus...

it is better to believe, for now, that the plane exploded mid-air and no one survived or strapped to a seat watching the plane dive down...

[JashiK]

I watched a clip on the news last night interviewing a passenger's wife, I wanted to bawl my eyes out when she said "I hope he wasn't frightened" :(

That is pretty sad......

[-cj-]

I read on a site today that the plane might have been flying through the storm at the wrong speed... Apparently Airbus issued a notice for 330's flying through storms. I believe it was on CNN.

[JashiK]

wrong speed? wonder how that affected the plane...?

[-cj-]

Good question, I was wondering about that myself... Maybe the A330 has some sort of issue? Generally when a company issues a notice for a specific item/vehicle/etc, it means that they've discovered that in certain situations that vehicle is prone to issues...

I'm just speculating based on what CNN said.

[Fobio]

wrong speed? wonder how that affected the plane...?


Good question, I was wondering about that myself... Maybe the A330 has some sort of issue? Generally when a company issues a notice for a specific item/vehicle/etc, it means that they've discovered that in certain situations that vehicle is prone to issues...

I'm just speculating based on what CNN said.

don't wanna sound like a dick considering what happened, but it seems like this, but in french:

"when you zee ze black clouds, you crank ze throttle lever all ze way to ze warp speed, and you fly your french ass around and AWAY from ze storm cloud, yes?"

[JashiK]

that pilot has some good flying hours. he also had some 1400-1700 flying hours on that very plane too.

[-cj-]

:chuckle Too soon! ;)

To make things really twisted, they said that all of the recovered debris they found was NOT from the plane! Neither was the oil slick....

[Thrizzl3]

:chuckle Too soon! ;)

To make things really twisted, they said that all of the recovered debris they found was NOT from the plane! Neither was the oil slick....

WATTT!!! soooo where is the plane?

[-cj-]

They don't know yet... At least, that's what I gathered. Maybe they know where the plane is, but the debris isn't from the plane. I think there's still more debris to go through tho.

[Thrizzl3]

where did you see this? link? http://www.thestar.com/news/world/article/645412

[AskClaudio.com]

It's on the Star website, there are three main articles.

One of the articles says a passerby plane, flying a commercial plane, air comet, noticed an object what appeared to be a plane take a nose drive fall into the ocean for a brief 6 seconds, like a white light and it was gone. He didn't think any of it at the time, the spanish pilot because nothing was reported over the radio.

[-cj-]

Phil: cnn...

Gino: I read the same thing on CNN, but they mentioned that he saw a very bright, intense LIGHT, and it disappeared after like 6 seconds into the ocean... But he never said that he SAW a plane go into the ocean... Although it's probably what happened. :/

Edit: Sorry, either I'm tired or you edited and through in 'object'... Thought you mentioned he saw a plane hit the water.

[aris]

This is crazy....i don't think they will ever find the black box

[openuser]

Jacob wanted them on the island...

Welcome to the land of living?

[slam525i]

wrong speed? wonder how that affected the plane...?

Airplanes have what is called a "turbulent air penetration speed".

Basically, if you encounter severe turbulence, you don't want to be going too fast or you will generate enough G force to break the airplane when you maneuver to compensate for turbulence. You also don't want to be going too slow or you might stall out (wings stop generating lift, you stop flying) and you also have less control when at low speeds (low speeds = less airflow over control surfaces = less control).

The professional pilot forums have been speculating for days what the problem could be, but no one has come up with a really good answer.

The Star's suggestion of pitot tube icing is somewhat questionable since there are dual, heated pitot tubes feeding independent computers.

This is the reason we don't fly through storms.

[Fobio]

I have also heard that the plane "auto-piloted" itself into the storm and the pilots didn't have much time to react or pull out of the path of the storm.

[JashiK]

Nice... didn't know this. Thanks~


Airplanes have what is called a "turbulent air penetration speed".

Basically, if you encounter severe turbulence, you don't want to be going too fast or you will generate enough G force to break the airplane when you maneuver to compensate for turbulence. You also don't want to be going too slow or you might stall out (wings stop generating lift, you stop flying) and you also have less control when at low speeds (low speeds = less airflow over control surfaces = less control).

The professional pilot forums have been speculating for days what the problem could be, but no one has come up with a really good answer.

The Star's suggestion of pitot tube icing is somewhat questionable since there are dual, heated pitot tubes feeding independent computers.

This is the reason we don't fly through storms.

[JashiK]

I have also heard that the plane "auto-piloted" itself into the storm and the pilots didn't have much time to react or pull out of the path of the storm.

Wouldn't they have received weather reports and alerts to avoid this storm? Things aren't adding up...

[Fobio]

Wouldn't they have received weather reports and alerts to avoid this storm? Things aren't adding up...

I've been reading a lot on this so I don't recall the source of this bit of info. But I recall that a meteorlogist states that the storm cell the flight flew into was a combination of smaller storm clouds. Planes do regularly fly through lesser storms...it could be that the forecast did not anticipate the gathering of a bunch of storm clouds into a supercell...

Having said that, there's also specualtion that a meteorite downed the plane and that is why there was a flash, and no debris...

[JashiK]

Man... if it was a meterorite that's insane. The odds of a meteorite hitting a moving plane would be crazy, but I guess possible.

[AskClaudio.com]

Whoa, a meteorite no way.

[AskClaudio.com]

There are so many conflicting reports. Something must be up here.

[JashiK]

I wonder if they'll ever be able to find out what did happen to this flight.

[Fobio]

I've been keeping an eye/ear out for news of any significant VIP that might've been on that flight...

[JashiK]

The possibilities... are almost endless at this point.
The black boxes give off a signal for 30 days.... I guess they haven't been able to receive the signal or else they would know the approximate location of the crash or where some of the debris would be.

[DruidB]

The water under the crash is 14000ft deep.... no one is going to find anything

[-cj-]

There was also a report from Airbus that the information the plane uploaded contained inconsistent airspeeds for the plane. So it's possible the plane might have stalled because of a faulty airspeed sensor or been flying through the storm at the incorrect speed, when the pilots thought everything was peachy...

[Hives]

Lost!

[Aceius]

Funny how now, France says the debris found was not from the wreckage, yet the Brazil army says it is...I have a feeling there's more than what anyone is saying.

[Aceius]

The water under the crash is 14000ft deep.... no one is going to find anything

The black boxes "ping out" so that sonar can pick it up, but if they don't find the general area and find the ping within 30 days then they're SOL.

[JashiK]

I've been keeping an eye/ear out for news of any significant VIP that might've been on that flight...


Funny how now, France says the debris found was not from the wreckage, yet the Brazil army says it is...I have a feeling there's more than what anyone is saying.

could it be possible....

[Flagrum_3]

could it be possible....

Well the maiden flight of this model from Airbus went down and back then rumors had it as being caused by a computer 'problem', if I remember correctly but everything basically was covered up to protect Airbus, whom had just spent hundreds of billions getting to that point!!.....So who knows!? ....I know personally, I don't trust Airbus products and won't fly them.


_3

[-RJ3-]

Unsure if this could be a connection, but I was watching Mayday, on discovery channel, and one of their conclusions that could have caused a crash is faulty "pilot tubes"...the episode was A turkey flight BOEING plane leaving from DR had thought the crash was due to faulty instrument indicators.. This wasn't the case, amazingly enough it was a blocked pilot tube that was giving wrong information to the flight cockpit during autopilot. The pilot also had signs prior to take off the plane's instrumentation malfunctioned.

This was resolved, but how scared to know that a blockage could cause a pilot's / plane make a wrong decision to crash.


BTW in the show it was concluded that the plane has lyed dorment for 25 days a mud dauber made a nest inside the pilot tube

http://pestcontrolcanada.com/INSECTS/bymudd_s.jpg

without those blackboxes, Im afraid this will be an open case for years to come!

[slam525i]

Unsure if this could be a connection, but I was watching Mayday, on discovery channel, and one of their conclusions that could have caused a crash is faulty "pilot tubes"...

That's a "pitot" tube, not a pilot tube. :chuckle

Basically, the pitot tube lets air ram into it, the pressure of which is then used to tell airspeed. That's the simplified explanation without going into how it interacts with the "static ports".

The official investigation of that accident stated:
"The crew's failure to recognize the activation of the stick shaker as a warning of imminent entrance to the stall, and the failure of the crew to execute the procedures for recovery from the onset of loss of control."
http://en.wikipedia.org/wiki/Birgenair_Flight_301

We're all trained to fly without the airspeed indicator in case of emergency. On airliners, there's at least two of these devices. Still, it's easy to get caught out if we don't recognize the failure.

[DruidB]

The black boxes "ping out" so that sonar can pick it up, but if they don't find the general area and find the ping within 30 days then they're SOL.

I realise that... but even if they locate it via sonar... nothing is going to dive 14k feet except for a mini sub or robot sub... very very slim chance of them finding it

[Fobio]

latest reports say that the US Navy and other research vehicles are sending unmanned subs. furthermore, they have on the way, ships that can listen to 20,000ft or just over 6000m or 6km...

[Cardinal Fang]

My wife and I flew back from Boston last summer and our pilot warned us of turbulent weather they flew through to get to Boston. We were hitting it on the return trip. There was a point in our trip where the plane did a series of violent motions where everything just shook for what seemed like 5 seconds ending in a violent push to the side and a loud thump. It sounded like someone hit the plane. I swear my neck hurt for days afterwords.

I can't imagine what type of violent motions those passengers experienced if it's true the plane broke apart during a storm.

[Fobio]

Courtesy of the Drudge Report:

Terror Names Linked To Doomed AIR FRANCE Flight...

http://news.sky.com/skynews/Home/World-News/Terror-Names-Linked-To-Doomed-Flight-AF-447-Two-Passengers-Shared-Names-Of-Radical-Muslims/Article/200906215300405?lpos=World_News_Carousel_Region_0&lid=ARTICLE_15300405_Terror_Names_Linked_To_Doomed _Flight_AF_447%3A_Two_Passengers_Shared_Names_Of_R adical_Muslims