The search for the missing AirAsia jet has resumed off Indonesia with officials believing the airliner may be at the bottom of the Java Sea.
But Indonesian search-and-rescue officials say they will expand their efforts to include land, hoping the plane may be on an island.
The United States is sending the Navy destroyer USS Sampson to help with the search efforts.
Several other nations have also offered help, including Australia, Malaysia, and Thailand.
Flight QZ 8501 with 162 passengers and crew was about halfway into its flight from the Indonesian city of Surabaya to Singapore when it disappeared Sunday morning.
The pilot asked air traffic controllers for permission to ascend about 1,800 meters to avoid stormy weather. An Indonesian Transport Ministry official said permission was denied because another plane was flying in the area. Air traffic controllers then lost contact with the jet
The passengers include 149 Indonesians, 3 South Koreans, and one each from Britain, Malaysia, and Singapore. The crew included 6 Indonesians and a French co-pilot.
Coming just nine months after the loss of a Malaysian jet that remains missing, the disappearance of AirAsia Flight 8501 is rattling many in a region where air travel and violent storms often intersect.
A day after the AirAsia jet disappeared during a storm, nervous passengers arrived in Singapore, having flown the same route from the Indonesian city of Surabaya.
"It's eerie," said passenger Nicole Go. "And the flight just now was really bumpy, and so, I don't know."
Weather often an issue for pilots in Southeast Asia
A pilot who has flown commercial airliners in the region told VOA weather -- including sudden storms -- has always been an issue for planes in Southeast Asia, and that pilots and controllers often have to rely solely on radio communications instead of newer and quicker technologies.
Before it disappeared from radar, the crew of the missing AirAsia plane asked to fly at a higher elevation to avoid some clouds.
“Some weather patterns, strong convective activity to aircraft of any size and so that’s why you see commercial pilots deviating around really strong cells of weather,” said Keith McGuire who is with the University of Southern California’s program for aviation safety and security.
But McGuire, a former regional director with the U.S. National Transportation Safety Board, said it's still way too early to blame weather for the loss of this plane.
“As new facts come in, it’s just human nature, there’s a tendency to look at it and say, ‘Oh, maybe this is it…,” he said. “But this early in the game, no, a professional investigator isn’t going to be jumping to any conclusions.”
For now, authorities are promising to look at every possibility.
Indonesia’s president told a news conference he ordered a review of all aviation procedures and processes.
Meanwhile, AirAsia Chief Executive Tony Fernandes and other company executives are doing their best to calm a jittery public.
“There’s a deep sense of depression here, but we’ll stay strong,” Fernandes said
He said AirAsia has carried 220 million people to this point and that “we are confident in our ability to fly.”
Indonesia is leading the search for the plane, which went down over the Java Sea about halfway through its flight. Malaysia, Singapore and Australia are taking part in the effort, and on Monday, Jakarta asked for United States for help. The State Department said it is determining how the U.S. can best aid the search.
Some information for this report came from AP, AFP and Reuters.