The AirAsia aircraft that went missing after taking off from Indonesia with 162 people on board may be at the bottom of the sea, a top Indonesian official said on Monday, as the multinational search for the Airbus continued amid fading hopes of finding any survivors.
"Based on the coordinates given to us and evaluation that the estimated crash position is in the sea, the hypothesis is (that) the plane is at the bottom of the sea," National Search and Rescue Agency chief Bambang Soelistyo told reporters in Jakarta.
"That's the preliminary suspicion and it can develop based on the evaluation of the result of our search," he said.
If the plane is found on the ocean floor, there would be a challenge in getting the plane to the surface because they do not have the "submersible" equipment, Soelistyo said.
Searching for the Singapore-bound Flight QZ8501, an Indonesian helicopter saw two oily spots in the Java Sea while an Australian search plane spotted "suspicious" objects near Nangka island, more than 1000 km from the location where contact with the plane was lost.
However, Indonesian Vice President Jusuf Kalla said the objects spotted by the Australian aircraft were not from the missing plane. "It has been checked and no sufficient evidence was found to confirm what was reported," Kalla told reporters at Surabaya airport from where the plane took off.
Indonesia Air Force spokesman Rear Marshal Hadi Tjahnanto told MetroTV that an Indonesian helicopter spotted two oily spots in the Java Sea east of Belitung Island, but there was no confirmation that the finding had a connection with the missing plane. Tjahnanto said the search was now focussed on the oil spots.
The vice president stressed that there was no time frame for the search mission and anything found will be treated with utmost importance.
"Indonesia hopes there will be survivors but is prepared for the worst," Kalla said.
The Airbus A320-200 lost contact with air-traffic control less than an hour after takeoff on Sunday. Contact with the plane was lost shortly after a request was made by the pilots to climb to a higher altitude to avoid bad weather.
The last communication from the pilot to radar control was a request to increase altitude from 32,000 feet to 38,000 feet because of rough weather.
The request was not immediately granted as there was reportedly another plane in airspace at 34,000 feet, said Bambang Tjahjono, director of the state-owned company in charge of air traffic control.
AirAsia Flight QZ8501 was carrying 155 passengers -- one British, one Malaysian, one Singaporean, three South Koreans, 149 Indonesians -- and seven crew members -- six Indonesians and a French co-pilot.
Seventeen of the passengers were children. There were no Indian nationals on board.
The missing aircraft belongs to Indonesia AirAsia, which is 51 per cent owned by Fersindo Nusaperkasa with the remaining 49 per cent equity held by Malaysian company AirAsia Berhad.
The plane's emergency locator transmitter should function automatically and send warning signals, but no signal has been detected by control centers in Indonesia or in neighboring countries, Indonesia's national search and rescue agency chief Soelistyo said. He confirmed that Indonesia's national search and rescue agency is spearheading the search effort.
The search was focused on a radius of 270 nautical miles off Indonesia's Bangka Island -- a center of tin mining and pepper cultivation south of Singapore -- and could be widened, Sulistyo said.
The search area for the missing plane was later expanded, as vessels scoured the waters for it. The search area initially focused on four sectors, but it was expanded to seven sectors, the agency said.
The search area was devised from data received when the plane lost contact, as well as supplementary data such as weather conditions.
Twelve ships, tens of boats and two helicopters for the search have been deployed by the Indonesian agency for the massive search operation.
Malaysia and Singapore are each deploying three ships and one Hercules plane, the Indonesian air force is deploying two Hercules planes, one Boeing 737 and two "Puma" aircraft, and the Indonesian navy is deploying two warships, authorities said.
Additionally, the Australian defence force has deployed an AP-3C Orion maritime patrol Aircraft to assist in the search. The Indonesia military's search and rescue team at Manggar in East Belitung have also been briefing fishermen of the search area.
Five nations, including India, have offered help in the massive search and rescue operation for the missing plane.
The six-year-old Airbus A320-200 was flying over the Java Sea in Indonesian airspace when communication with air traffic control ceased about 42 minutes after take-off from Juanda Airport. The aircraft was to land at Singapore's Changi Airport at 8.30 am. The pilot had asked for a new route minutes before he went off the radio, air traffic control said.
The plane's last detected position was 100 nautical miles south-east of Tanjung Pandan on Belitung Island.