http://www.usatoday.com/news/world/2009-06-03-air-france-flight_N.htmWreckage yields clues in jet crash
Search vessels prowling the Atlantic Ocean on Wednesday found a 23-foot-long chunk of Air France Flight 447, the largest piece discovered yet in the hunt for clues in the mystery of the downed airliner.
The latest piece of wreckage floated about 55 miles from where debris was originally spotted on Tuesday. The enormous distance between the debris fields strongly indicates that the plane came apart in the air Sunday night, showering parts across a wide swath of ocean, aviation experts said. The Airbus 330-200 was carrying 228 people from Rio de Janeiro to Paris when it entered a fast-developing thunderstorm.
Air France's CEO Pierre-Henri Gourgeon told families of passengers on Flight 447 that the jetliner broke apart and they must abandon hope that anyone survived, said Guillaume Denoix de Saint-Marc, a grief counselor who was asked by Paris prosecutors to help counsel family members and was at the Wednesday meeting.
U.S. aviation experts monitoring the recovery said that information released so far suggests the jet was jarred while cruising at 35,000 feet by an external force that knocked out key electrical systems and may have broken up the plane. Satellite data show thunderheads were sending 100-mph updrafts into the jet's flight path.
"It is likely that we do have an in-flight breakup," aviation-safety consultant John Cox said.
Also among the debris was a 12-mile oil slick. "Oil stains on the water might exclude the possibility of an explosion, because there was no fire," Brazilian Defense Minister Nelson Jobim said.
Search crews continued sailing toward the remote ocean spot hundreds of miles from Brazil's northern coast. It will take until early next week for the most important vessel to arrive: a French ship with remote-controlled submersibles that will search for "black box" recorders.
Crew conversations and airplane movements contained in the recorders would be vital to solving the crash, but France's chief accident investigator, Paul-Louis Arslanian, said Wednesday that he is "not optimistic" about finding the two boxes because they are likely a couple of miles underwater on a craggy ocean floor.
In the minutes before disappearing, the jet sent a series of automated messages indicating damaged controls, electrical failure and a loss of cabin pressure.
"There was some kind of in-flight violent" incident, said Bill Waldock, an air-crash expert at Embry-Riddle Aeronautical University in Prescott, Ariz.
Waldock suspects weather — namely, the 100-mph winds the airplane apparently encountered that could have gotten underneath the wings and shaken the plane. "If they hit a 100-mph updraft while they were going 525 mph, it would have thrown them violently," Waldock said. "It's way beyond what the airplane is designed to accept."
The force could have bent or torn off a wing, Waldock said.
Extreme winds also could have blown the airplane into an unnatural position — nose down, or angling sharply to one side — that can lead to sharp acceleration as a plane tries to right itself, said former Boeing accident investigator Kevin Darcy. Usually a plane's computer will quickly regain control, but not always, Darcy said.
"In a loss of control, the plane speeds up. It goes faster than it's designed to, and you could have a flutter or structural problem where the airplane shakes itself apart," Darcy said.
Another possibility is lightning causing some kind of catastrophic damage, although many experts say the odds of that happening are extremely low because modern-day planes are designed to withstand lightning strikes. Several planes in the 1960s were downed when lightning hit a wing — the typical location for strikes — and ignited a fuel tank. Airplane redesigns moved fuel tanks to safer locations and made planes generally more resistant to strikes, Darcy said.
However, some modern planes are made of composite materials that may not be as durable against lightning, said former National Transportation Safety Board inspector general Mary Schiavo. A strike could knock out a plane's electrical system, ignite a fire or damage the fuselage, Schiavo said.
"If you get a bolt of lightning, anything can go apart, depending on what's the voltage," Schiavo said.
A sudden jolt also could have come from a bomb. Officials have discounted terrorism, and Brazilian Defense Minister Nelson Jobim said, "That possibility hasn't even been considered." Former Boeing safety engineer Todd Curtis said foul play is possible, albeit unlikely. "At this point in the investigation, nothing can be ruled out.