The AirAsia plane which went missing with 162 people on board en route for Singapore is likely at the bottom of the sea, Indonesia's National Search and Rescue Agency chief said Monday.
"Based on the coordinates given to us and evaluation that the estimated crash position is in the sea, the hypothesis is the plane is at the bottom of the sea," Bambang Soelistyo told a press conference.
"That's the preliminary suspicion and it can develop based on the evaluation of the result of our search."
Soelistyo said Indonesia did not have "the tools", such as submersible vehicles, required to retrieve the plane from the seabed, but that it is reaching out to other countries for help if necessary.
"Due to the lack of technology that we have, I have coordinated with our foreign minister so we will borrow from other countries which have offered. They are the UK, France and US," he said.
Watch: AirAsia flight QZ8501 goes missing, relatives anxiously await news at Singapore airport
More countries join search
Meanwhile, more than 24 hours after flight 8501 disappeared, the search has expanded with planes and ships from several countries taking part.
First Admiral Sigit Setiayana, the Naval Aviation Center commander at the Surabaya air force base, said that 12 navy ships, five planes, three helicopters and a number of warships were talking part, along with ships and planes from Singapore and Malaysia. The Australian Air Force also sent a search plane.
Setiayana said visibility was good. "God willing, we can find it soon," he told The Associated Press.
AirAsia Flight 8501 vanished in airspace thick with storm clouds on its way from Surabaya, Indonesia, to Singapore. Searchers had to fight against heavy rain on Sunday before work was suspended due to darkness.
The plane's disappearance and suspected crash caps an astonishingly tragic year for air travel in Southeast Asia. The Malaysia-based carrier's loss comes on top of the still-unexplained disappearance of Malaysia Airlines Flight 370 in March and the downing of Malaysia Airlines Flight 17 in July over Ukraine.
At the Surabaya airport, passengers' relatives pored over the plane's manifest, crying and embracing. Nias Adityas, a housewife from Surabaya, was overcome with grief when she found the name of her husband, Nanang Priowidodo, on the list.
The 43-year-old tour agent had been taking a family of four on a trip to Singapore, Malaysia and Indonesia's Lombok island, and had been happy to get the work.
"He just told me, 'Praise God, this new year brings a lot of good fortune,'" Adityas recalled, holding her grandson tight while weeping uncontrollably.
Nearly all the passengers and crew are Indonesians, who are frequent visitors to Singapore, particularly on holidays.
The Airbus A320 took off Sunday morning from Indonesia's second-largest city and was about halfway to Singapore when it vanished from radar. The jet had been airborne for about 42 minutes.
There was no distress signal from the twin-engine, single-aisle plane, said Djoko Murjatmodjo, Indonesia's acting director general of transportation.
The last communication between the cockpit and air traffic control was at 6:13 a.m. (23:13 GMT Saturday), when one of the pilots asked to increase altitude from 32,000 feet (9,754 meters) to 38,000 feet (11,582 meters), Murjatmodjo said. The jet was last seen on radar at 6:16 a.m. and was gone a minute later, he told reporters.
Indonesia, Singapore and Malaysia launched a search-and-rescue operation near Belitung island in the Java Sea, the area where the airliner lost contact with the ground.
AirAsia has good safety record
AirAsia group CEO Tony Fernandes flew to Surabaya and told a news conference that the focus for now should be on the search and the families rather than the cause of the incident.
"We have no idea at the moment what went wrong," said Fernandes, a Malaysian businessman who founded the low-cost carrier in 2001. "Let's not speculate at the moment."
Malaysia-based AirAsia has a good safety record and had never lost a plane.
But Malaysia itself has already endured a catastrophic year, with 239 people still missing from Flight 370 and all 298 people aboard Flight 17 killed when it was shot down over rebel-held territory in Ukraine.
AirAsia said Flight 8501 was on its submitted flight plan but had requested a change due to weather. Sunardi, a forecaster at Indonesia's Meteorology and Geophysics Agency, said dense storm clouds were detected up to 13,400 meters (44,000 feet) in the area at the time.
"There could have been turbulence, lightning and vertical as well as horizontal strong winds within such clouds," said Sunardi, who like many Indonesians uses only one name.
Airline pilots routinely fly around thunderstorms, said John Cox, a former accident investigator. Using on-board radar, flight crews can typically see a storm forming from more than 100 miles away.
In such cases, pilots have plenty of time to find a way around the storm cluster or look for gaps to fly through, he said.
"It's not like you have to make an instantaneous decision," Cox said. Storms can be hundreds of miles long, but "because a jet moves at 8 miles a minute, if you to go 100 miles out of your way, it's not a problem."
Authorities have not said whether they lost only the secondary radar target, which is created by the plane's transponder, or whether the primary radar target, which is created by energy reflected from the plane's body, was lost as well, Cox said.
The plane had an Indonesian captain, Iryanto, who uses one name, and a French co-pilot, five cabin crew members and 155 passengers, including 16 children and one infant, the airline said in a statement. Among the passengers were three South Koreans, a Malaysian, a British national and his 2-year-old Singaporean daughter. The rest were Indonesians.