Monday's announcement by the Malaysian government that Malaysian Airlines Flight 370 crashed into the Indian Ocean does little to solve the mystery of what happened to that ill-fated flight. It may be many years before any answers emerge on how 239 passengers and crewmembers died in the accident.
Aviation experts say it may take months to years to recover wreckage and the cockpit voice and flight data recorders of the Boeing 777, which disappeared after taking off from Kuala Lumpur, bound for Beijing, more than two weeks ago. It could also take years before an accident report is released with a probable cause.
Malaysian Prime Minister Najib Razak announced at a press conference Monday that analysis of satellite data indicated the Boeing 777 crashed into a remote part of the Indian Ocean, and all lives were lost.
Analysis of satellite data is a very preliminary step, and wreckage and the recorders must be recovered before facts are established, says former National Transportation Safety Board accident investigator Al Yurman.
"Some parts have to be recovered and positively identified that they came from that Malaysia Airlines plane," Yurman says.
Once there is positive identification, investigators "have to backtrack" and find a debris field to determine whether the plane made a controlled or an uncontrolled descent into the ocean, he says.
A debris field "could be 20 miles or hundreds of miles" from where satellite images showed what is believed to be wreckage of the Malaysian jumbo jet.
Former National Transportation Safety Board chairman Jim Hall says there could be multiple debris fields. He says much depends on ocean currents that could have scattered wreckage.
"We don't know how many debris fields there are," Hall says.
Hall and Yurman say the depth of the Indian Ocean— which has an average depth of 12,990 feet — may make it difficult to recover wreckage, and they expect most or much of the wreckage will not be recovered.
It took nearly two years to recover the so-called black box containing the cockpit-voice and flight-data recorders after Air France Flight 447 crashed into a remote area of the Atlantic Ocean in 2009. All 228 passengers and crew aboard the plane heading from Rio de Janeiro to Paris were killed.
The U.S. Navy is moving a black-box locator into the area of the Indian Ocean where searchers are looking for wreckage of the Malaysian Airlines plane, the Department of Defense said Monday.
The move "is a precautionary measure in case a debris field is located," the department said.
If a debris field is confirmed, the Navy's Towed Pinger Locator 25 "will add a significant advantage" in locating the missing jet's black box, the department said.
Navy Commander Chris Budde said the locator has "highly sensitive listening capability" that "can hear the black box pinger down to a depth of about 20,000 feet."
The locator and an underwater surveillance vehicle were flown from New York's JFK airport Monday and will arrive in Perth, Australia, according to Rear Admiral John Kirby, the Pentagon's press secretary.
If a debris field is found, the locator will be brought to the scene and towed slowly by a ship, Pentagon and Navy officials said. Slow speed is needed for the locator to detect the ping emitted from the black box.
Neither Hall nor Yurman expect wreckage from the Malaysia Airlines plane to be reconstructed on land to give investigators clues to the cause of the crash, as was done by U.S. and Canadian aviation authorities after jetliners crashed into the Atlantic Ocean in two accidents two decades ago.
A TWA Boeing 747 jet broke apart and fell into the ocean after takeoff from JFK airport in July 1996, killing all 230 people aboard. It took more than four years before an accident report was released. The report stated a probable cause could not be found, but the most likely cause was a wiring short-circuit that ignited a center fuel tank.
In September 1998, Swissair Flight 111 bound from New York to Switzerland crashed near Nova Scotia, Canada, killing all 229 people aboard. Five years later, the Canadian accident investigators released a report saying that the most likely cause was short-circuited wiring.
Causes of airline accidents are not always found.
"The probable cause of the Malaysia Airlines accident could end up undetermined," Yurman says.
Yurman says that, until wreckage is recovered and more information is learned — particularly from the cockpit-voice and flight-data recorders — he could not speculate whether the plane crashed from mechanical problems or actions of anyone in the cockpit.
The search for wreckage is very costly.
The Defense Department estimates that $4 million "set aside" to assist in the search with other countries will last until the beginning of April.
On Friday, the department said the cost of its role in the search, including operating costs of ships and aircraft, had reached $2.5 million.
Hall says an international agreement to divide the cost of the search must immediately be reached between the countries involved. Hundreds of millions of dollars were spent in the search to recover the Air France wreckage, he says.
Contributing: Jim Michaels in Washington