NO SURVIVORS
No survivors have been found from the crash, which happened about 40 minutes after the plane took off from Indonesia's second largest city in an area known for intense tropical thunderstorms during the current monsoon season.
A report from Indonesia's weather bureau said it was likely the plane had flown into bad weather which would have been difficult to avoid, and that it was possible this had caused ice to form on its engines.
"Based on the available data on the last received location of the aircraft, the weather was a factor in causing the accident," the weather bureau said.
Indonesian authorities on Friday questioned whether the pilot had followed correct weather procedures, and later suspended Indonesia AirAsia's Surabaya to Singapore flights, saying the airline's operating licence only permitted flights on Mondays, Tuesdays, Thursdays and Saturdays.
Djoko Murdjatmodjo, Indonesia's acting Director General of Air Transportation, said on Saturday that the Transport Ministry would investigate other routes used by the carrier, which flies from at least 15 Indonesian destinations.
"We are going to investigate all AirAsia flight schedules. Hopefully we can start on next Monday," he said. "It is possible AirAsia's licence in Indonesia might be revoked," he added.
Sunu Widyatmoko, Indonesia AirAsia chief, told reporters the airline, which is 49-percent owned by Malaysia-based AirAsia , would cooperate with the inquiry.
"The government has suspended our flights from Surabaya to Singapore and back," he said. "They are doing the evaluation process. AirAsia will cooperate fully with the evaluation."
Much effort has focused on finding the mostly Indonesian victims of the crash. Thirty bodies have been recovered from the sea, although rescue official Supriyadi, who like many Indonesians uses just one name, said it was unlikely more would be found floating.
"Because we're already in the seventh day ... the chances are they have all sunk," he said. "There's a possibility they'll be found on beaches."
Small pieces of the aircraft and other debris have also been found, but there has been no sign of the crucial voice and flight data recorders - the so-called black boxes that investigators hope will unravel the sequence of events in the cockpit during the doomed jet's final minutes.