Authorities have been careful to stress that scenario for the missing AirAsia plane is drastically different from that of Malaysia Airlines flight MH370, which went missing in March and has yet to be found.
Australian Prime Minister Tony Abbott said "it would be a big mistake to equate what has happened here with MH370," telling Sydney's Radio 2GB that MH370 was "one of the great mysteries of our time."
The area of the Java Sea where the AirAsia plane went missing is typically 40 to 50 meters (130 to 164 feet) deep — compared with the 4,000 meter-plus depths complicating the MH370 search, U.K.-based oceanographer Dr. Simon Boxall told NBC News.
"Until today, we have never lost a life"
"It's relatively shallow water and it's close to land so they can use helicopters, rather than spending hours just getting to the search area," said Boxhall, who is based at at the University of Southampton. "It's not going to be easy, but it is feasible within a relatively short amount of time."
The Airbus A320-200, which was travelling from Surabaya to Singapore, had 155 passengers as well as two pilots and five crew members on board. Most of the passengers are Indonesian. Three people on board are from South Korea, and one person each is from Singapore, Malaysia, Britain and France. Seventeen passengers are children, and one is an infant, the airline said.
Relatives of many of the passengers were flocking to the Singapore Changi Airport, where the missing plane was supposed to arrive, for updates.
AirAsia CEO Tony Fernandes has called the disappearance "a nightmare." He told reporters that his thoughts are with those who have loved ones on board.
"Until today, we have never lost a life," Fernandes told reporters in Jakarta airport, according to the AP. "But I think that any airline CEO who says he can guarantee that his airline is 100 percent safe, is not accurate."
The plane was supposed to arrive at Changi at 8:30 a.m. Singapore time (7:30 p.m. ET Saturday). The pilot had asked for permission to climb from 32,000 feet to 38,000 feet to avoid clouds, said Joko Muryo Atmodjo, air transportation director at Indonesia's transport ministry, according to Reuters. Permission was not granted.
— Cassandra Vinograd, The Associated Press and Reuters contributed to this report.
ELISHA FIELDSTADT
Elisha Fieldstadt is a staff writer for NBC News. She started this role in January of 2014.
Missing AirAsia Flight Likely on 'Bottom of the Sea,' Search Official Says - NBC News