Air France plane didn't break up? Skepticism grows.

French accident investigators now say they believe Air France Flight 447 did not break-up mid-flight, but instead plunged on its belly into the water and broke up on impact. The conclusion is based on the condition of the wreckage recovered so far.

Investigators also said they would suspend the current search for the plane's flight-data recorders, which hold crucial information on the cause of the crash, on July 10. After that, they'll continue the search using advanced sonar technology.

All 228 passengers perished on the flight from Rio de Janeiro to Paris June 1.

The conclusion by the French accident investigation agency, known as the BEA, drew criticism from aviation analysts. But the decision to continue the search for the black boxes was welcomed.

Aviation analysts note the French investigators still do not have access to the autopsies of the bodies recovered from the crash, which led Brazilian authorities to conclude the plane probably broke up mid-air. Analysts also wonder how such a conclusion could be reached with the small amount of wreckage recovered so far. They note that it's possible for one or more of the plane's components to have failed or broken up in the flight, which could have precipitated the fuselage's plunge into the ocean.

"How do they know [the plane broke-up on impact] based on what little information they have so far? It seems like a pretty big leap," says Clint Oster, an aviation expert at Indiana University at Bloomington. "It may well be that the wreckage pattern indicates that most of the airplane was intact when it hit, but there's a big difference between most of the airplane being intact and all of the airplane being intact."

Analysts say it is vital to continue the search for the black boxes, particularly because the mystery surrounding the cause of the crash has raised questions about the use and testing of composite materials as well as the complexity of the Airbus's flight control computer systems. As a result, analysts say this is an important accident to understand thoroughly.

"It would make sense to spend some time and effort and money to locate [the flight data recorders]," says Robert Mann, president of R.W. Mann & Company, aviation consultants in Port Washington, N.Y. "I would think that Airbus, the other ancillary equipment manufacturers, and the French BEA ought to be interested in that."

"In the absence of [the recorders], we're getting wildly conflicting information about what may have occurred," he adds.

The Monitor has confirmed that the BEA is still in discussions with Louisiana-based C&C Technologies, an undersea mapping company that has the technical capabilities to continue the search using automated undersea vehicles and a side-scan sonar approach.

Analysts say it is a promising technology. Company president Thomas Chance said it was "likely" that the black boxes and more of the wreckage could be found using side scan sonar, but that it could take several months. No contract has been signed yet.

Aviation analysts note that in past accidents – like the crash of TWA Flight 800, which crashed off the coast of Long Island in July of 1996 – accident investigators spent millions of dollars recovering the wreckage and then painstakingly reconstructing the aircraft in order to discover the cause of the crash.

"These are very expensive operations, with TWA 800 they didn't know what brought that plane down, but they were bound and determined to find out," says Professor Oster. "That's because of the question: If we don't understand what brought this plane down, how will we know it won't bring another one down?"

During Thursday's news conference outside Paris, an adviser to France's accident investigation board said he did not believe that the concerns by the Flight 447 crash raised are sufficient to ground other Airbus A330 aircraft.

"The information available today does not indicate any such need," Philip Swan, an adviser to the BEA, told a news conference, according to Reuters. "They have flown tens of millions of hours and there are 660 of them flying."

But some aviation analysts disagree strongly with that conclusion.

"They have not looked into the myriad instances of computerized control system glitches that have occurred during those 'tens of millions of hours,' and how they might well be related to a series of cascading events that may have doomed Flight 447," writes Lee Gaillard, an aviation analyst based in Saranac Lake, N.Y., in an e-mail.