JAKARTA, Indonesia: Determining what caused an Indonesian jetliner to plunge into the sea with 102 people is important for global aviation safety in case there are structural problems with the world's most popular aircraft, experts said Saturday.
Signals from the Boeing 737's flight recorders, also known as black boxes, have been traced to the ocean floor at a depth of about 1,700 meters (a mile), but the government says it does not have the sea salvage technology needed to recover them.
The Adam Air plane disappeared after running into 130 kilometer (80 mile) per hour winds off Sulawesi island on New Year's Day. The pilot did not issue a mayday or report technical problems before the jetliner fell off radars at 10,000 meters (35,000 feet).
Indonesia has asked for international help recovering the black boxes, but with their battery life of 30 days about to expire, "time is of the essence," said Jim Hall, a former chairman of the U.S. National Transportation Safety Board.
"If you lose the signal, you don't have anything to hone in on," he said. "At that depth there will likely be visibility problems, currents can move sediment over the box and pieces of wreckage ... you may not be able to recover it at all."
"The safety of citizens that fly not just in Indonesia but across the globe depends on finding that black box," Hall added.
Initially, search and rescue teams thought the plane crashed on land and, with no emergency beacon to guide them, deployed thousands of troops across Sulawesi's dense jungles and remote regions, losing valuable time.
A fisherman eventually found a section of the tail in Makassar Strait and more than 200 pieces of debris have since been plucked from the waters. But the main fuselage, engine, cockpit, wings and other parts key to the investigation have yet to be recovered.
"We just don't know," said Ken Johnson, the former executive of the Transportation Safety Board of Canada, noting that the crash could be tied to poor maintenance, pilot error, sabotage, weather, structural faults or "a million other reasons."
"It might be very, very simple, but conversely, it could be something extremely important," he said.
Johnson noted that it took a yearslong US$40 million investigation to determine that a 1998 Swissair crash off Canada's eastern coast was the result of an electrically-sparked fire fed by insulation between the jet's aluminum skin and its cabin.
That led to a major overhaul of the way the planes were manufactured and certification standards, he said, pointing to several other such examples.
"In the unlikely event the Adam Air crash was a problem with the aircraft, it's pretty important to find it and fix the worldwide fleet," Johnson said.
So far, more questions than answers remain.
An Indonesian transportation investigator said the pilot reported strong crosswinds from the left in his last radio transmission, but the control tower said the wind was coming from the right, pointing to possible navigational problems.
The plane, which twice had to change course because of the rough weather, also could have been turned around, Ruth Simpatupang said.
Boeing refused to comment, saying the accident investigation was ongoing. A representative from the Chicago-based company was in Indonesia to offer assistance.