The passengers onboard the flight include 138 adults, 16 children and one infant. Also on board were two pilots, including a French co-pilot, and five cabin crew.

AirAsia said there were 149 Indonesian passengers onboard, three South Koreans, one Briton, one Singaporean, and one Malaysian.

Prime Minister Tony Abbott spoke with Indonesian President Joko Widodo to express his condolences and offer assistance.

Mr Abbott told the Indonesion President that Ausralia had a P3 Orion aircraft on standby ready to assist the search if it was required.

Foreign Affairs Minister Julie Bishop said she understood no Australians were on the plane.

"It's always deeply concerning when we hear news such as this and all we can do is ascertain as much as we can about the details of the flight and to determine whether there were any Australians on board," Ms Bishop said.

She also added that she had offered Australia's "support and assistance".

The missing plane departed at 5.35am Indonesian time (9.35am AEDST) and was scheduled to arrive at 8.30am Singaporean time (11.30am AEDST).

Transport Ministry official Hadi Mustofa said the aircraft lost contact with the Jakarta air traffic control tower early Sunday morning. AirAsia said this occured at 7.24am local time (11.24am AEDST).

Mr Mustafa said the last communication was from the pilot asking for permission to change the height from 32,000 to 34,000 feet in the Kumai Strait near Belitung due to bad weather.

J.A. Barata, a spokesman for the Ministry of Transportation, said the pilot had asked to go to 38,000 feet to avoid clouds to the left.

Just five minutes later, at 6.17am local time, the tower in Jakarta lost contact with the aircraft. At 6.18am it had vanished from the radar. At 7.55am the flight was officially declared missing. When it went missing, the plane still had enough fuel for four hours flying time.

As a press conference, Indonesia's Minister for Transport, Ignasius Jonan, said the flight went missing between Tanjung Pandan and Pontianak, and, on the last contact, it was not far from the shoreline.

The search would begin where it went missing and then get wider. Search and rescue agencies were on the move from Singapore and civilian shipping was asked to provide any information if they saw anything.

The Minister of Transport asked the media not to make any assumptions, but to be patient, and as soon as they had any information it would be released. They intended to give an hourly update at the airport.

Indonesian vice-president Jusuf Kalla announced late on Sunday there was a "high possibility that an accident has happened".

"The government is deploying all force: military, search and rescue, and is using all available personnel and equipment to locate the plane, whether it's on land or water," said the vice-president, who based himself on Sunday at the search and rescue headquarters in Jakarta.

However, FHB Soelistyo, the head of Indonesia's national search and rescue agency, Basarnas, drew attention to the relative weakness in Indonesia's technology, saying the sonar on their boats only reached to a depth of 200m.

Mr Soelistyo said a command centre would be set up by 6am Monday in Pangkal Pinang, on one side of the Karimata Strait, where the plane went missing.

Malaysian and Singapore flights would arrive and be operational from Monday.

Tatang Zaenudin, deputy of personnel from Basarnas, said seven ships to search in the sea near Belitung had been deployed however the rescue boats were not expected to arrive at the area until midnight local time (4am AEDST).

Local head of Basarnas Joni Superiyadi said that poor weather conditions and waves of one to two meters are believed to be hampering the passage of the boats.

Basarnas has also dispatched four helicopters, including one dispatched from Jakarta which was expected to make it to the site in three hours, arriving around 3pm local time.

Mr Tatang said two Hercules aircraft had also been cleared to fly from Singapore to the site, and preparations were underway to speed up the process to approve flights from Australia to assist. 

The local search and rescue chief from Pangkal Pinang, Joni Superiyadi, told Fairfax Media the closest rescue ship was 100 miles from the point where the plane went missing. It would take six to 10 hours at 10 to 15 knots for the boat - the fastest they have - to get there.

Any report of debris found at the scene was false: he had received no notification from any private vessel, he said.

A crisis centre has been set up at Surabaya airport and relatives have begun arriving to tearfully view a full list of names of those who were on the flight.

Passengers' relatives told airport officials in Surabaya they had been trying the mobile phones of their loved ones without success.

Indonesian vice-president Jusuf Kalla tweeted: "We pray together with hope that the AirAsia plane QZ8501 SBY-Sin, which lost contact, is soon found and all passengers and crew have survived."

AirAsia chief executive Tony Fernandes tweeted: "Thank you for all your thoughts and prays. We must stay strong," 

One woman at the crisis centre had seven family members including her mother and brother on board the flight.

In posts on Facebook and Twitter, AirAsia confirmed the plane had gone missing.

"AirAsia Indonesia regrets to confirm that flight QZ8501 from Surabaya to Singapore has lost contact with air traffic control at 07:24hrs this morning," the airline said.

"At the present time we unfortunately have no further information regarding the status of the passengers and crew members on board, but we will keep all parties informed as more information becomes available."

Shortly after the airline posted its first message, it changed its Twitter and Facebook profile pictures, removing its red and white logo and replacing it with a grey and white one.

"At this time, search and rescue operations are in progress and AirAsia is cooperating fully and assisting the rescue service," the airline said.

"AirAsia has established an Emergency Call Centre that is available for family or friends of those who may have been on board the aircraft. The number is: +622129850801.

"AirAsia will release further information as soon as it becomes available. Updated information will also be posted on the AirAsia website, www.airasia.com."

AirAsia said the captain in command had a total of 6100 flying hours and the first officer a total of 2275 flying hours.

The aircraft, an Airbus A320-200 with the registration number PK-AXC, had undergone its last scheduled maintenance on November 16.

The head of the rescue operation from the Indonesian search and rescue agency said there were three possibilities when a plane lost contact at the height it did: engine failure, that it had ditched over the sea, or was diverted to another airport.

The other airports in the region have been contacted, but have no record of a diversion, he said.

Airforce spokesman Marsma Hadi Tjahjanto confirmed the air force was using the last point of contact to conduct an air search. He said the air force radar recorded the weather at the time as cloudy.

Indonesian aviation expert Gerry Soejatman tweeted that the Indonesian Air Force had dispatched a 737-200MPA to search for the missing flight, and had cited the weather in the area as "challenging".

Mr Soejatman also tweeted an alleged leaked photograph from the Air Traffic Control screen which showed the plane was last spotted at 36,300 feet and climbing, but that its ground speed was a very slow 353 knots.

Eric Schultz, a White House spokesman, said that US President Barack Obama, who is vacationing in Hawaii, had been briefed on the search for the plane, and that "White House officials will continue to monitor the situation".

AirAsia was embroiled in controversy earlier this year after publishing an article in their in-flight magazine claiming their planes would "never get lost".

The airline was forced to withdraw the Travel 3Sixty magazine from circulation in April after the comment sparked outrage due to the disappearance of Malaysian Airlines flight MH370 in March.

The article told travellers "Pilot training in AirAsia is continuous and very thorough. Rest assured that your captain is well prepared to ensure your plane will never get lost".

However, AirAsia insisted the article was written and published well before the disappearance of flight MH370.

An apology was issued for the article by AirAsia executive chairman Kamarudin Meranun. "It truly saddens me that this article was released at such an inopportune moment," he said.

It has been a year to forget for Malaysian airline companies, given the disappearance of MH370 in March and MH17 in July.

The wreckage of Malaysia Airlines Flight 370 has not been found nine months on, as well as the 227 passengers on board. 

Meanwhile, Malaysia Airlines Flight 17 was expected to touch down in Kuala Lumpur from Amsterdam, but was shot down over area controlled by pro-Russian separatists. All 283 passengers and 15 crew on board were killed. 

smh.com,au, with Reuters, AP and staff