Determining what caused an Indonesian jetliner to plunge into the sea with 102 people is important for global aviation safety in case there are any structural problems with the world's most popular aircraft, experts said yesterday.
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 1,700m, but the government says it does not have the sea salvage technology needed to recover them.
The Adam Air plane disappeared after running into 130km 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 10,000m.
Indonesia may seek international assistance to recover 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 US National Transportation Safety Board.
"This is the most widely used airplane in the world, so the safety of citizens that fly not just in Indonesia but across the globe depends on finding that black box," he told reporters by telephone.
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.
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 crucial parts have yet to be found.
"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 or structural faults.
"It might be very, very simple, but conversely, it could be something extremely important," he said.
Johnson noted that it took a US$40 million investigation into the 1998 crash of Swissair Flight 111 off Canada's coast to determine that an electrical spark in the insulation between the MD-11 jet's skin and cabin had triggered a fire.
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.