One AirAsia victim was wearing a life jacket

Indonesian Search and Rescue crews lift the body of an AirAsia passenger onto a stretcher at the airport in Pangkalan Bun, central Kalimantan on Wednesday. [Photo/Agencies]

A body recovered on Wednesday from the crashed AirAsia plane was wearing a life jacket, an Indonesian search and rescue official said, raising new questions about how the disaster unfolded.

"This morning, we recovered a total of four bodies and one of them was wearing a life jacket," Tatang Zaenudin, an official with the search and rescue agency, told Reuters.

He declined to speculate on what the find might mean. But a pilot who works for a Gulf carrier said the life jacket indicated the cause of the crash was not "catastrophic failure". Instead, the plane could have stalled and then come down, possibly because its instruments iced up and gave the pilots inaccurate readings.

"There was time. It means the thing didn't just fall out of the sky," said the pilot, who declined to be identified.

He said it could take a minute for a plane to come down from 30,000 feet and the pilots could have been "too overloaded" to send a distress call. "The first train of thought when you get into a situation like that is to fly the aircraft."

After sonar detected a large, dark object in waters near where debris and bodies were found on the surface, rescuers now believe they have located the remains of the plane on the ocean floor off the island of Borneo.

The authorities in Surabaya have been making preparations to receive and identify bodies, including arranging 130 ambulances to take victims to a police hospital and collecting DNA from relatives.

Indonesian President Joko Widodo said the priority now is retrieving the bodies.

However, the massive search operation for the plane was hampered by heavy rain, wind and thick clouds, and although sonar images have shown what appear to be large parts of the plane strong currents are moving the wreckage and the weather prevented divers from going down on Wednesday.