Two weeks after an Indonesian plane vanished with 102 passengers and crew, investigators admitted on Monday they still did not know exactly where or why the aircraft apparently came down.
All they have found in two frustrating weeks of searching is a fragment of tail-fin and a few pieces of cabin debris washed up on the shore.
With just tantalising fragments of the Adam Air Boeing 737-400 to work on, investigators hope the massive air, land and sea search of waters off the west coast of Sulawesi Island will provide the breakthrough they need to solve the riddle of Flight KI 574.
Speculation on the cause ranges from an explosion to the aircraft hitting an air pocket.
“We cannot yet come to a conclusion,” admitted Setio Raharjo, head of the National Committee for Transport Safety, before a parliamentary hearing.
Speaking to reporters, he added: “It is also too early to conclude that a scenario where the airplane exploded in mid-air took place; there are so many possibilities.”
The plane was carrying 96 passengers, including three Americans, and six crew when it went missing halfway through its routine flight from Surabaya on the central island of Java to Manado on Sulawesi on January 1.
The pilot did not send a distress call but he did report that the plane was being buffeted by cross-winds shortly before it disappeared from radar.
The only significant find so far, a 1m section of tail-fin, is just a tiny part of the missing plane, which measures 36,5m in length with a wingspan stretching nearly 29m.
A Singaporean reconnaissance plane helping the search spotted an oil spill in the waters off South Sulawesi, but it needed further analysis.
“It should really be ascertained whether the oil spill comes from aircraft Avtur [aviation turbine fuel],” Raharjo said, adding that samples had still to be taken from the sea.
Tata Lanang, who sits on the safety committee, said that if it was aviation fuel, it indicated the aircraft had hit the sea intact.
“Just use logic. If the aircraft had exploded in the air, the fuel would be spread over a wide area,” Lanang told Agence France-Presse. “If it is a single large oil slick then it is very likely that the fuel tank broke only after the aircraft hit the water.”
The head of the Indonesian Institute for Aviation Studies, Kamis Martono, has been widely quoted as speculating about an air pocket, a localised area of low pressure that can cause a sudden loss of altitude.
Flight-crew error is the leading cause of hull-loss accidents, according to a Boeing study of worldwide commercial jet accidents from 1996 through 2005.
Crew error was ruled the primary cause in 55% of accidents while the aircraft was blamed in 17% and the weather in 13%.
Singapore has deployed four sets of equipment staffed by six navy operators to detect the plane’s underwater beacon locator and track down its “black box” flight recorder, which should shed light on the mystery.
The Detikcom online news portal reported that the Singaporean team and its equipment was bound for Pare-Pare, a port near the area where debris has been found at sea.
Joseph Tumenggung, a member of the National Committee on Transport Safety, said the black box should be able to transmit an ultrasonic signal for 30 days unless severely damaged.
The search for the black box has focused on waters over 1Â 000m deep off the coast of West Sulawesi where sonar searches detected three large metal objects on the sea bed.
The United States Navy oceanographic survey ship USNS Mary Sears has confirmed one of the objects is “round-shaped metal,” but more readings are needed to determine whether they were part of the missing plane.
Meanwhile, searchers also combed the seas off Barru district where debris from the plane has been washed up on beaches.
Aircraft and ferry accidents are common in Indonesia, a vast archipelago nation stretching over 5Â 000km. — AFP