Did Lightning Doom Air France Jet?

(CBS/AP)  The lightning and turbulence that may have hit an Air France jet flying from Rio de Janeiro to Paris are rarely the cause of plane crashes, analysts say. But they note that rough weather may have triggered a series of malfunctions that led to the disappearance of the jetliner.

Chief Air France spokesman Francois Brousse suggested the plane could have been struck by lightning.

But most experts say lightning doesn't usually bring down a modern airliner, unless it coincides with other factors that contribute to the accident.

"Planes are built with lightning strikes in mind and are struck reasonably frequently," said Patrick Smith, a U.S. commercial pilot and aviation writer.

"I've been hit by lighting in my career a number of times, which at worst resulted in a superficial mark on the outside of the plane," Smith said in a telephone interview from Sao Paolo, Brazil.

Lightning strikes can be catastrophic on the ground, but in aviation they are a daily and uneventful occurrence, reports CBS News correspondent Nancy Cordes. That's because jets like the Airbus 330 are built with materials that shed lightning charges and are equipped with redundant electrical systems - if one shorts out, another takes its place.

"It's a little bit of an adventure for a moment because it's like a flashbulb going off in your face," Jack Casey, COO of Safety Operating Systems, told Cordes. "But beyond that, that wasn't a big concern for us."

Aviation safety statistics indicate that each large passenger jet - such as the Airbus A330 - is struck by lightning about once every three years on average. Regional aircraft however, which fly at lower altitudes, are hit more frequently - about once a year.

Although lightning may have been a contributing factor in a handful of accidents since World War II, only one major crash was attributed directly to a strike. In 1963, a Pan American World Airways Boeing 707 exploded in midair when its fuel tank fumes were ignited by lightning.

Since then, aircraft electronic components have been hardened to withstand electric pulses of that magnitude, and new systems have been designed to prevent sparking in fuel tanks.

About seven hours after taking off and flying through the night over the mid-Atlantic, the pilots of the Air France Airbus reported that they had encountered an area of intense cumulonimbus activity, part of the massive thunderstorms that regularly batter the world's equatorial belt.

To avoid structural damage, both military and civilian pilots use standard onboard radar to maneuver around the thunderheads, which are characterized by electrical discharges, hail and high winds.

The mid-Atlantic region is where most hurricanes that hit the Western Hemisphere originate, and this is the beginning of the storm season. Thunderheads in the area can tower up to 60,000 feet, making it impossible for airliners to fly over them and forcing them to make long diversions.

It remains unclear whether Flight 447 took evasive action to avoid the area of heavy turbulence.

Air France reported that the aircraft's ACARS (Aircraft Communications and Addressing System) - a digital datalink that automatically transmits service messages from the aircraft to ground stations - messaged the company's headquarters regarding a problem with the aircraft's electrical and pressurization systems.

Former NTSB chairman Jim Hall said that, since the A330 is widely used in international travel, it was vitally important to locate the black boxes as quickly as possible and analyze what happened to Flight 447.

"At this point accident investigators can't rule out anything," he said. "But these aircraft are designed to withstand almost any lightning strikes or any level of turbulence."

Although aviation experts stressed it was much too early to speculate about the causes of the crash, they noted that the accident was most likely caused by various factors that combined to cause a catastrophic chain of events.

"It sounds like something that evolved into a problem, not something that happened instantly," said Bill Voss, president and CEO of Flight Safety Foundation, in Alexandria, Virginia.

"It would appear that their systems were degrading but we don't know why they were degrading."

Smith said that that if the crew was forced to ditch the A330 in the ocean at night in stormy weather, "the outcome would not likely have been a good one."

"It would be nothing like landing that Airbus at midday in the Hudson river, a completely different scenario," Smith said, referring to the successful Jan. 15 water landing of a US Airways Airbus A320 in New York.

[craigbennie]

Both pilots of the Air Comet flight from Lima to Lisbon sent a written report to aviation authorities, i.e, Air France, Airbus, describing what they saw. They reported that "Suddenly, we saw a bright flash....an intense flash of white light, ....in a descending and vertical trajectory....." in the area of Flight 447.

Recalling the January 7, 1948 incident of Kentucky Air National Guard Captain Thomas Mantell, Jr., who was ordered to intercept a UFO sited over Mansville, Kentucky, one notices a strange similarity in eyewitness testimony. Witness farmer Glen Mays of Franklin, KY said he saw Mantell's plane "enveloped by a brilliant white flash of light...so bright....it was like looking at the sun". Captain Mantell's aircraft then "appeared to fall out of this light and pancake into the ground" Mays said.

There's a commonality between the Air France Flight 447 tragedy and Captain Mantell's crash---- reports of a mysterious intense flash of white light preceding the doomed aircraft. Just coincidence?... or something more frightening?

[NancyLou9]

While I sure can't blame Bush OR Obama for this, I saw in another article the followingL

"President Barack Obama told French television stations the United States was ready to do everything necessary to find out what happened to the missing plane."

I have to wonder why he's telling this to the French television stations rather than picking up a phone and telling it to the French government, or the French military or, well, anyone but the teleivsion stations?

Is it that he can't even speak without the benefit of a teleprompter? Is he such a media ***** that he HAD to tell the French television stations?

Perhaps someone could have written something down on paper and slid it beneath his hand while he called President Sarkozy?

The country of France lost at least twelve people on that airplane and he should have picked up a stupid telephone to, at the very least, express his condolences. The rest of the country feels for not just France but the other countries that lost citizens on that plane, including the United States. We as a country are doing more to express our condolences than the POTUS.

Sad that Obama has no more raising than this.

[rrozsa]

I'm sure someone will manage to blame it either on GW Bush or Obama. Aren't all the ills of the world caused by one or the other, according to the majority of CBS News commenters?

Seriously, I do hope they are able to pinpoint where the aircraft went down and figure out what happened to cause this tragedy. My thoughts and prayers are with the families of the victims.

[richhong]

And this is why they are used in every modern US fighter and many US military transports.
Posted by veils-2009 at 11:06 PM : Jun 1, 2009

Safety is not of paramount importance in the design of military aircraft. Performance is. Military aircraft crash with some regularity during routine flights. Far, far more often than passenger airliners.

[pensacola8-2009]

Control surface motion evolved from mechanical, to hydraulic, and then to "fly-by-wire".

If weather was a factor, I would focus more on engine FOD.

[veils-2009]

.... The downside is the belief held by some that fly-by-wire systems are more fragile.
Posted by richhong

And this is why they are used in every modern US fighter and many US military transports.

[brian408]

The as yet unasked questions might center on ground crew interviews and on how thoroughly luggage--legal and otherwise--was inventoried before the flight departed. Evidence thus far indicatesa sudden, catastrophic event; -such as an explosive charge. That'd certainly account for the "sudden electrical failure," and, of course, the loss of pressurization, not to mention the lack of communication from the aircrew.
The later reported sighting of glowing debris spots by a passing airliner suggest that the aircraft descended in pieces and that they must have been burning on the way down. Beyond an explosion, there's just not much else that could cause such an outcome. Pressurization loss at 35,000 feet is "right now trouble, " even with oxygen masks. Oxygen supplied during a cataclysmic fire is not a good thing. Just a few thoughts . . .

[common2cents]

"
1. Although a "fly by wire" system is in the A330, are not there mechanical overrides?"

In short, no. Airbus designs their planes with hard limits in mind (for example, you can't climb at greater than 30 degrees). Mostly these are limits that if the pilot tries to break, he's going to crash the plane anyway, so they might as well stop him from doing that. Boeing gives the pilot a warning and uses physical feedback (e.g. it becomes harder to pull the stick back) in order to limit pilot overcorrection, but the pilot has the final say. There are upsides and downsides to each method, but that's not really for this discussion board.

[pensacola8-2009]

Posted by cattlekate1 at 4:15 PM : Jun 1, 2009

Good Questions

Fly by wire systems are not backed up by mechanical systems. An electrical bus is the electrical power transport - usually a DC based power system.

Every plane that is certified does have to survive extreme control surface deflections and none of the wings or control surfaces are allowed to tear or fall away to attain certification in either the general aviation or commercial air transport category.

DC bus failures are rare and nearly all commercial air transport aircraft have at least one redundant pair of DC power transmission systems feeding every critical device on the plane. Complete loss of redundant power systems is not considered an option for normal flight conditions, even with severe turbulence or weather phenomena.

Lightning strikes can have disabling affects on sensitive circuits and computers, but on an aircraft, a fail-safe back-up computer that is not sensitive to lightning is supposed to take over critical flight system operations upon main system failure. It provides limited function and can become overtasked under certain conditions, because it is designed to keep the aircraft flying straight and level and keep cabin environment safe and engines operating with pre-planned system defaults.

The catastrophic loss of critical flight systems in flight is generally not considered a high possibility for normal flying conditions, even with severe weather and lightning strikes.

The scenario that plays through my mind recalls an even on February 19, 1985, when China Air Flight 006 lost control after an engine failure and several hours of pilot neglect caused a 747 to tumble out of the sky at 41,000 feet and barely regain control within 1,500 of the ground. Flight control surfaces were partially torn away from exceeding the "G's" the aircraft was designed to survive. It was truly a miracle fight to survive that not even test pilots dare to reproduce with airliners. Check it out on Wikipedia.

[richhong]

Thank you for answering my question! So you are saying...
Posted by cattlekate1 at 5:23 PM : Jun 1, 2009

Cattlekate: I can't speculate helpfully any further on what might have happened here. The overall fear in fly-by-wire is that the wires tend to be more fragile than mechanical or hydraulic linkages, and while a damaged hydraulic control will degrade gradually, if a fly-by-wire circuit fails, it's sudden and complete. The design concern is that the tail is a narrow space full of critical components. And you can't control a plane if you lose tail control. The wiring to the tail, even if you run the primary and backup cables as far apart as possible along the fuselage - those bundles come together in the tail. So if something happens in the tail, the event can take out both the primary and backup cable bundles, resulting in a loss of tail control followed by what would likely be an unhappy ending.

Again, this is PURE unhelpful speculation, but my first thought was a fire below the passenger deck that took out the wiring, resulting in loss of control. How could this happen? I don't know. Could it be from lightning? Theoretically yes. But the plane is designed against that possibility. The bottom line is that planes aren't supposed to crash, so whatever happened wasn't supposed to happen.

Anyway, fly-by-wire is a tradeoff. FBW systems are lighter than mechanical linkages, saving fuel. They can also be programmed to prevent a pilot from performing maneuvers that exceed the capabilities of the aircraft, increasing safety. The downside is the belief held by some that fly-by-wire systems are more fragile.