Indonesian rescuers saw bodies and luggage off the coast of Borneo island on Tuesday and officials said they were "95 percent sure" debris spotted in the sea was from a missing AirAsia plane with 162 people on board.
Indonesia AirAsia's Flight QZ8501, an Airbus A320-200, lost contact with air traffic control early on Sunday during bad weather on a flight from the Indonesian city of Surabaya to Singapore.
Pictures of floating bodies were broadcast on television and relatives of the missing gathered at the crisis centre in Surabaya were shown weeping, their heads in their hands.
Media quoted an air force official earlier as saying one suspected body, luggage and a life vest were among the debris in the Java Sea. "As we approached, the body seemed bloated," said First Lieutenant Tri Wibowo, who was on board a Hercules aircraft, was quoted by the Kompas.com website as saying.
Search and Rescue Agency chief Soelistyo told reporters he was "95 percent sure" the debris was from the missing plane. Djoko Murjatmodjo, acting director general of air transportation at the transportation ministry, told reporters some of the debris spotted was red and white, AirAsia's colours.
"It's probably from the aircraft," he said. About 30 ships and 21 aircraft from Indonesia, Australia, Malaysia, Singapore, South Korea and the United States were searching up to 10,000 square nautical miles on Tuesday.
The plane, which did not issue a distress signal, disappeared after its pilot failed to get permission to fly higher to avoid bad weather because of heavy air traffic, officials said.
Pilots and aviation experts said thunderstorms, and requests to gain altitude to avoid them, were not unusual in that area. The Indonesian pilot was experienced and the plane last underwent maintenance in mid-November, the airline said.
Online discussion among pilots has centred on unconfirmed secondary radar data from Malaysia that suggested the aircraft was climbing at a speed of 353 knots, about 100 knots too slow, and that it might have stalled.
The plane, whose engines were made by CFM International, co-owned by General Electric and Safran of France, lacked real-time engine diagnostics or monitoring, a GE spokesman said. Such systems are mainly used on long-haul flights and can provide clues to airlines and investigators when things go wrong.