Air France plane missing?

[saupatel]

Is it safe to say that this incident was not caused by just the storm system since a KLM and TAM flew the exact same route and landed safely ?

[ATFS_Crash]

I am merely wildly speculating at this point. So take what I say as early speculation and opinion.

This mishap raises my concerns and suspicion that some plastic composite designs may be more vulnerable to lightning strikes than legacy aircraft that were virtually entirely metal skinned and metal frame. I am ignorant on the design of this particular aircraft; but I understand it has more composites than legacy aircraft and that some newer designed aircraft have even more of a higher ratio of plastic composites.

I feel that legacy aircraft that were mostly metal skinned and metal framed aircraft were often better protected from lightning strikes and EMP, because of an umbrella/skin effect/and/or Faraday Cage effect.

There also is a another phenomena that may be a factor. I don't remember the exact science but it's something like this. Not all lightning strikes are the same. I think most lightning strikes are typically what is called negative lightning. I think there is a rare form of lightning that is often called and considered positive lightning. This rare form of lightning is supposed to be much more powerful than typical lightning. I think it is often so powerful that it is often associated with sprites and super sprites. Apparently some of this more powerful lightning has the ability to reach from the edge of space clear to the surface of Earth. I think that less than 5% of lightning is the rare form of positive lightning. I think this rarer form of lightning has much higher voltage, amperage and has a much longer duration than typical lightning; so it is more likely to do damage.

Apparently some of these newer fly by wire systems don't have a mechanical backup. That seems to suggest that if there is a major catastrophic failure such as a lightning strike or EMP that manages to significantly compromise the wiring harness and/or electronics; but there may be total loss of control of the aircraft.

I was on a camping trip when a small but severe storm was severe lightning and wind struck. I was 20 feet away from a base of a tree that was about 3 feet in diameter; when it snapped at the base and the tree fell; but the wind was so strong I couldn't hear the tree snap or fall. The lightning was absolutely incredible. After the storm moved out we could hear campers about a quarter mile away yelling as if they were in distress. We grabbed our first aid kit; ax; and hardware and canoed over to investigate and offer our help. One of the campers had laid a fishing pole that was made of carbon fiber up against a tree. Lightning had struck the tree and traveled down the skin of the tree onto the fishing pole. The fishing pole was hollow, so the electricity largely traveled on the inside and outside surfaces of the fishing pole. The fishing pole exploded. One of the campers had carbon fibers embedded into his chest and arm. We did our best to help remove the carbon fiber shrapnel from his chest and arm. We gave them antibiotic sauves, oral antibiotics, and almost all of our gause and anti-septics. It was about two days travel to civilization (before they could see a doctor).

Anyway that fishing Rod mishap leads me to believe that not only are composite aircraft are more vulnerable electrically/electronically to electrical failures from lightning strikes and EMP; that I feel that lightning strikes could possibly cause fire and/or explosion and/or structural failure of the composites.

I suspect/hope that wiring is required to be shielded from lightning strikes. I would hope that they would design the structures of aircraft to redirect lightning to where it would be less likely to do harm. If this mishap is found to be from lightning strike(s) I would hope that they would increase their efforts.


I fear that as plastic composite aircraft become more popular and that the amount of plastic composites that are used increases; that lightning may become more of a factor than they have been in the past.

[KBUF]

Is it safe to say that this incident was not caused by just the storm system since a KLM and TAM flew the exact same route and landed safely ?

Actually, TAM flew the reverse route. Not so sure about KLM, though.

[Gabriel]

ATFS, I lack the knowledge to respond to your post from a technical point of view.

However, I can attempt a statistical approach:

Many business jets have been built mainly from composites for 10, may be 20 years now (including fairings, control surfaces, fin and horizontal tail, fuselage and even wings).

Probably several thousands of them take off every day around the world. They fly similar altitudes and in similar weather as the airliners. Necessarily, they must have received thousands of lighting strikes by now.

When was the last time you've heard one of those was downed by a lighting strike? I have never heard of one.

And that fact doesn't seem to change despite the proportion of "plastic" planes grow every day as new plastic jets are delivered and old aluminium ones are retired (not that there are not new aluminium ones, but the tendency is certainly towards the use of plastic).

Yes, composites means a special challenge regarding lighting protection.
I don't know how or what they are doing, but whatever it is it looks they are dealing ok with it.

[CotterPin]

I fear that as plastic composite aircraft become more popular and that the amount of plastic composites that are used increases; that lightning may become more of a factor than they have been in the past.

Doesn't equate to the data that is available. Hundreds of thousands, of composite crafted flights have taken place without a hitch. One can assume that most of the world's A330 fleet has been struck by lightning at some point. It's very common, taking place on the order of once-per-month, if not more frequently, for commercial a/c.

Don't forget that composite skinned planes have been in widespread use for several decades, in both military and civilian applications. This is the reason why the lightning hypothesis is hard to accept, though not an impossibility.

[Danno_FZ1]

Weather data for AF447

I love the fact that this forum draws out a great mix of wild speculation and solid factual rebuttal. Hopefully in time we'll have good information from the FDR's.

Here's some good data to parse:

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

Peace be with those who lost loved ones or friends on this flight.

[phoneman]

Explosion

Based on other pilots who witnessed fires burning in the ocean. it seems to me that there was an explosion of some sort. It the plane hit the water intact there would unlikely be any fire, just like the Swissair crash. But an explosion would ignite the fuel while the plane is still airborn, leaving burning fuel on the ocean just like TWA 800. The question for me is was it a bomb, or lightning igniting a fuel tank. What do you guys think?


The pilots spotted two areas of floating debris - but no signs of life - about 35 miles (60 kilometers) apart, about 410 miles (650 kilometers) beyond the Brazilian archipelago of Fernando de Noronha, near Flight 447's path from Rio de Janeiro to Paris, said Air Force spokesman Jorge Amaral.

[MKalafatas]

Search for CVR/FDR

If these units are resting on the bottom of the ocean, can their signals even be detected by a boat operating on the surface 13,000 feet above?

It will be an amazing accomplishment to find them. Surely the odds are stacked heavily against....

[HalcyonDays]

If these units are resting on the bottom of the ocean, can their signals even be detected by a boat operating on the surface 13,000 feet above?

It will be an amazing accomplishment to find them. Surely the odds are stacked heavily against....

It will be an achievement but nothing new. In fact, more than 20 years ago the recorders from the South African 747 that went into the Indian Ocean were recovered from at least 15,000 feet. It can be done if they are found, the will is there to recover them, and provided the cost is not a problem.

[James Bond]

If these units are resting on the bottom of the ocean, can their signals even be detected by a boat operating on the surface 13,000 feet above?

It will be an amazing accomplishment to find them. Surely the odds are stacked heavily against....

Yes, up to 20,000 ft for one month.

[Evan]

I fear that as plastic composite aircraft become more popular and that the amount of plastic composites that are used increases; that lightning may become more of a factor than they have been in the past.

This is an excerpt from the Composites World article I linked to earlier, dated 7/1/2006:

If a lightning bolt strikes an unprotected structure, up to 200,000 amps of electricity seeks the path of least resistance. In the process, it may vaporize metal control cables, weld hinges on control surfaces and explode fuel vapors within fuel tanks if current arcs through gaps around fasteners. These direct effects also typically include vaporization of resin in the immediate strike area, with possible burn-through of the laminate. Indirect effects occur when magnetic fields and electrical potential differences in the structure induce transient voltages, which can damage and even destroy onboard electronics that have not been EMF (electromagnetic field) shielded or lightning protected.

It goes on to enumerate different surface protection strategies, such as embedding copper wire mesh to the surfaces. I'm interested to know which, if any, of these protections are in use by Airbus.

The horizontal stabilizer on the A330 is a composite structure. It houses the trim tank. Other composite structures include the vertical stabilizer and wing control surfaces.

For those looking for actual facts, the complete article once again:

http://www.compositesworld.com/articles/lightning-strike-protection-for-composite-structures.aspx

[Quench]

It activates with the water, it sends an acoustic signal, it has a self contained battery which may last up to 3 days, if the aircraft is too deep, you can send an acoustic probe attached to a wire....

I thought the pingers lasted 30 days minimum.

[Eric Diffoot]

Brazil confirms Air France jet crashed in ocean


http://news.yahoo.com/s/ap/20090602/...a/brazil_plane

By FEDERICO ESCHER and ALAN CLENDENNING, Associated Press Writers Federico Escher And Alan Clendenning, Associated Press Writers – 3 mins ago

FERNANDO DE NORONHA, Brazil – Brazilian military planes found a 3-mile (5-kilometer) path of wreckage in the Atlantic Ocean, confirming that an Air France jet carrying 228 people crashed in the sea, Defense Minister Nelson Jobim said Tuesday. Jobim said the discovery "confirms that the plane went down in that area" hundreds of miles (kilometers) from the Brazilian archipelago of Fernando de Noronha.

He said the strip of wreckage included metallic and nonmetallic pieces, but did not describe them in detail. No bodies were spotted in the crash of the Airbus in which all aboard are believed to have died.

The discovery came just hours after authorities announced they had found an airplane an airplane seat, an orange buoy and signs of fuel in a part of the Atlantic Ocean with depths of up to three miles (4,800 meters).


At least now they can start looking for the FDR.

[Evan]

More on Composites and Lightning

1) This from an aerospace engineering blog (can't vouch for its accuracy):
Modern aircraft designs, Boeing & Airbus, generally do not now use embedded mesh in panels and rely on the conductivity of CFC and lightning wicks bonded to prime structure through metal straps. Mesh is used to provide ground planes for radio antennas and EMC shielding where it is needed but not otherwise.

2) Check out the Astrostrike page (worth it just for the AMAZING video of a midair lightning strike): http://www.astrosealproducts.com/

3) This from Seattlepi.com. (If Boeing is still working out the problem for the 787, I have to wonder how Airbus would have done so for the A330).

Aerospace Notebook: Lightning a weighty issue for the 787

By JAMES WALLACE
P-I REPORTER

On average, lightning strikes a commercial jetliner once or twice a year.

Usually, nothing much happens.

But Boeing's 787 Dreamliner will have a composite airframe, not the traditional aluminum skin.

And making sure the 787 is safe from lightning strikes in flight has driven up the plane's weight, especially in the wing where the fuel is stored.

The 787 is about 2.5 percent above its target weight, which is how much Boeing would like the plane to weigh when it is ready to be delivered to airlines. Much of that extra weight is in the wings and reflects changes that have been made to ensure there will be no serious consequences from a lightning strike.

Boeing said it is not sure it will be able to meet the target weight of the 787, but the plane will be within the weight promised to airline customers.

Mike Sinnett, director of 787 systems, said Boeing knows more about what happens when lightning hits a plane than anyone else.

On an aluminum plane, he said, a bolt of lightning can leave a tiny pinhole in the skin. That would require that systems behind the hole be checked.

On the composite fuselage or wing skin of the 787, although the impact area would be about the size of a baseball from the lightning hit, there would not be penetration of the skin, Sinnett said.

Still, the lightning will look for any path of least resistance into the composite material, such as through a wing-skin fastener. Making sure that does not happen has meant adding materials or changing the design, which has increased the weight of the wing.

"We always planned to deal with this issue, but we did not anticipate the complexity," acknowledged Boeing's Scott Strode, head of 787 development and production.

[Cargo Runner]

Based on other pilots who witnessed fires burning in the ocean. it seems to me that there was an explosion of some sort. It the plane hit the water intact there would unlikely be any fire, just like the Swissair crash. But an explosion would ignite the fuel while the plane is still airborn, leaving burning fuel on the ocean just like TWA 800. The question for me is was it a bomb, or lightning igniting a fuel tank. What do you guys think?

First of all I think we should put any sort of terrorist/bomb theory to the very back of our minds as no one has tried to claim any sort of press coverage by it and after 2 days you would think something would of leaked so far.

As for the fire theory, if there was a storm at the time of disappearance, how could anyone see anything in pouring rain, because I can't see when driving on the road what is happening above me or 1/2 a mile in front of me so I think this pilot is trying to get some type of fame out of this disaster....