One week after an AirAsia jet crashed into the Java Sea, Indonesian divers equipped with cameras and sonar beacons plunged into the storm-tossed waters Sunday after officials said four large objects had been detected on the sea floor.
Indonesian news reports said that at least 21 navy divers were searching for the objects — ranging in length from 24 to 60 feet — that officials believed were parts of the body of the ill-fated Airbus A320-200. Search teams were mounting an effort to retrieve the bodies of passengers as well as the flight recorders, which could hold clues to why the plane crashed Dec. 28.
"I can confirm that these are parts of the plane we are looking for," Bambang Soelistyo, head of Indonesia's National Search and Rescue Agency, said Saturday.
Poor visibility and strong currents have prevented divers from getting close enough to confirm the location of the fuselage. Of the 162 passengers and crew members aboard, only 30 bodies have been recovered.
Teams had struggled again Saturday against high waves to lower a remotely operated underwater vehicle to capture clearer images of the objects about 100 feet below the surface.
An Indonesian Geological Survey vessel estimated the size of the objects and determined that they were close enough to one another — and within the area off Borneo where investigators believe the plane would have crashed — to be parts of the jet.
The littoral combat ship Fort Worth joined the destroyer Sampson, a fellow U.S. Navy vessel, in the search area Saturday, American officials said.
The combat ship, which had just begun a Singapore-based deployment, would be used to conduct visual and radar searches in the shallow Java Sea and was equipped with two rigid-hull inflatable boats that were expected to participate in surface search efforts, according to a statement from the U.S. Navy 7th Fleet, based in Japan.
Indonesia AirAsia Flight 8501 crashed after encountering a thunderstorm during a two-hour flight from Surabaya, Indonesia, to Singapore. The pilot asked to shift to a higher altitude to avoid the storm but the request was denied because of other air traffic. Minutes later, ground controllers lost contact with the jet.
The cause of the crash remains unknown, but Indonesian government researchers who examined meteorological conditions believe that bad weather was "the trigger factor."
"The most likely weather phenomenon was icing, which could cause damage to the aircraft's engine due to cooling," said a 14-page report published by Indonesia's Meteorology, Geophysics and Climatology Agency.
Indonesia has seen heavier-than-usual monsoon storms in what is normally the wettest time of the year in the Southeast Asian nation.
The researchers described icing — in which ice forms on the surface of the aircraft or inside the engine — as "just one of the possibilities." Experts agreed, noting that there was no record of a distress call from the cockpit, which would have been expected had one or both engines suffered damage.
"I'm not surprised those weather conditions were present, but we don't know if the airplane went into those clouds or not," said Gerry Soejatman, an aviation consultant in Jakarta. "It's still a mystery."
Indonesia's Antara news agency reported Saturday that the nation's civil aviation authority has suspended AirAsia's permit to fly the Surabaya-Singapore route because the airline violated an agreement.
The news agency quoted Transportation Ministry spokesman Julius Andravida Barata as saying that AirAsia had no permit to fly the route from Surabaya on Sundays. Under an agreement with the government, the airline could serve the route only on Mondays, Tuesdays, Thursdays and Saturdays.
The suspension will remain in place until the investigation of the crash is completed, Barata said.
Officials with the Malaysia-based low-cost airline — which flies mainly short-distance routes across Southeast Asia and had never experienced a fatal accident — said it would not comment on the suspension while the investigation was underway.
"AirAsia management will fully cooperate with the government in that evaluation process," Indonesia AirAsia Chief Executive Sunu Widyatmoko said during a news conference in Surabaya.
Also Saturday, the American Embassy in Jakarta, the Indonesian capital, issued a security alert warning of "a potential threat against U.S.-associated hotels and banks in Surabaya."
It was not immediately clear whether the warning had anything to do with the crash investigation. A U.S. official in Jakarta, who requested anonymity under diplomatic protocol, said only that U.S. embassies "routinely" issue warnings to keep citizens informed of security issues overseas.
Surabaya is Indonesia's second-largest city, with a population of about 3 million. Although Indonesian authorities have forcefully cracked down on domestic militant groups, Western embassies have periodically issued security alerts since the 2002 bombings in the beach hot spot of Bali, which killed more than 200 people.
Special correspondent Pathoni reported from Jakarta and Times staff writer Bengali from Mumbai, India.