JAKARTA - Indonesian Vice-President Jusuf Kalla, speaking at a press conference in Surabaya, appealed to families of the passengers on missing AirAsia flight QZ8501 to remain patient. He said utmost efforts to search for the plane are being carried out, but no wreckage has been found yet.

The Indonesia AirAsia plane, an Airbus A320-200 carrying 162 people, disappeared after its pilot failed to get permission to fly higher to avoid bad weather during a flight from the Indonesian city of Surabaya to Singapore on Sunday.

Mr Kalla also pointed out that Sunday was not the optimal day for the search, because it was not done for a full day.

Monday will be a full-day search, Mr Kalla said, placing high hopes on the operation.

"This is our biggest search operations that we have ever done.

"Searching at sea is not as easy as that on land. But we have faced similar difficulty in the past, the Adam Air crash, which by God's help we finally found it," he said.

"Up to now, there is no sign of wreckage that has been spotted. No indication towards that yet."

Mr Kalla also confirmed that foreign aid is already in the search area, including foreign specialists. All are working hard, he added.

Flight QZ8501 did not issue a distress signal and disappeared over the Java Sea five minutes after requesting the change of course, which was refused because of heavy air traffic, officials said.