The plight of Indonesia AirAsia Flight QZ8501 that went missing over the Java Sea cannot be equated with Malaysia Airlines Flight MH370 which vanished without a trace in March, Australian Prime Minister Tony Abbott said Monday. 

Australia is leading the search for MH370 which was on a routine flight from Kuala Lumpur to Beijing when it disappeared off radars on March 8 with 239 people on board. 

"I think it would be a big mistake to equate what has happened here with MH370," Abbott told Sydney radio station 2GB after the budget airliner said a flight carrying 162 people was missing. 

"MH370, as things stand, is one of the great mysteries of our time. It doesn't appear that there's any particular mystery here. 

"It's an aircraft that was flying a regular route on a regular schedule, it struck what appears to have been horrific weather, and it's down. But this is not a mystery like the MH370 disappearance and it's not an atrocity like the MH17 shooting down." 

MH17, also a Malaysia Airlines flight, was shot down on July 17 over rebel-held territory in eastern Ukraine, killing all 298 people on board - among them 38 Australian residents. 

MH370 is believed to have crashed in the Indian Ocean far off Australia's west coast after diverting off course for an unknown reason and flying for several more hours over the remote waters. 

An intense air and sea search failed to find any wreckage from the aircraft, while an underwater search has been underway for weeks in the area considered the plane's most likely resting place with no result.

The disappearance of MH370 provoked a string of theories, including that it had been hijacked.
But aviation expert Neil Hansford said that such a scenario was unlikely for Indonesia AirAsia Flight QZ8501, an Airbus A320-200. 

"These are very different circumstances to MH370," Hansford told Sydney's Daily Telegraph.      
"This plane does not have the range to go very far for a major detour." 

Abbott said he was sure that aviation experts would convene to come up with more effective ways to track planes following the events of 2014, to ensure "that we don't just lose planes".

He said Australia would make itself "as available as we can be" to assist Indonesian authorities in the search for the Indonesia AirAsia plane which was heading to Singapore from Surabaya in Indonesia's east Java when it disappeared in bad weather on Sunday. 

An Australian air force AP-3C Orion joined the search early Monday.

An AirAsia plane carrying 162 people that went missing after its pilot failed to gain permission to alter course to avoid a storm is believed to have crashed into the sea, a senior Indonesian rescue agency official said on Monday.

Indonesia was searching the Java Sea on Monday for the AirAsia plane that went missing on Sunday during a flight from the Indonesian city of Surabaya to Singapore.

"Based on our coordinate estimation, initial estimation is in the water," Soelistyo, head of Indonesia's search and rescue agency, said of the missing plane's likely location.

"It can be expanded based on evaluation," he told reporters on Monday.