"It is believed the flight had circled over the sea near Belitung to avoid a storm before it experienced severe turbulence and crashed into the ocean."
AirAsia, a regional low-cost carrier founded in 2001 by Malaysian businessman Tony Fernandes, said in a statement that the missing Airbus A320-200 was on the submitted flight plan route.
Relatives of the passengers onboard AirAsia flight QZ8501, check the plane's manifest at a crisis center at Juanda International Airport. Photo / AP
However, it had requested deviation due to weather before communication with the aircraft was lost while it was still under the control of the Indonesian Air Traffic Control.
AirAsia, which has a presence in most of Southeast Asia and recently in India, has never lost a plane before and has a good safety track record.
"We don't dare to presume what has happened except that it has lost contact," Djoko Murjatmodjo, Indonesia's acting director general of transportation, told reporters.
He said the last communication between the pilot and air traffic control was at 6:13 a.m. when the pilot "asked to avoid clouds by turning left and going higher to 34,000 feet (10,360 meters)."
He said there was no distress signal from the cockpit.
The contact was lost about 42 minutes after the single-aisle, twin-engine jetliner took off from Surabaya airport, Hadi Mustofa, an official of the transportation ministry, told Indonesia's MetroTV.
It was about an hour before it was scheduled to land in Singapore.
Relatives of the passengers of AirAsia flight QZ8501 comfort each other at Juanda International Airport in Surabaya, East Java, Indonesia. Photo / AP
The plane had two pilots, five cabin crew and 155 passengers, including 16 children and one infant, AirAsia Indonesia said in a statement. Among the passengers were three South Koreans and one each from Singapore, Malaysia and France. The rest were Indonesians.
There are believed to be no New Zealanders on board but the New Zealand Embassy in Jakarta is following up with local authorities, says MFAT.
AirAsia said the captain in command had a total of 6,100 flying hours, a substantial number, and the first officer a total of 2,275 flying hours.
DO YOU KNOW ANYTHING ABOUT QZ8501?
At Surabaya airport, dozens of relatives sat in a room, many of them talking on mobile phones and crying. Some looked dazed.
As word spread, more and more family members were arriving at the crisis centre to await word.
An electronic sign board shows information for AirAsia flight QZ8501 bound for Singapore International Airport. Photo / AFP
Murjatmodjo, the Indonesian official, said the plane is believed to have gone missing somewhere over the Java Sea between Tanjung Pandan on Belitung island and Pontianak, on Indonesia's part of Borneo island.
Transport Minister Ignasius Jonan told reporters in Surabaya that the position was believed to be near the coast line. He said search and rescue efforts now involved the Indonesian army, the national Search and Rescue Agency as well as Singapore and Malaysia.
But that effort will focus on the area around Belitung island.
In a statement after the plane went missing, AirAsia Indonesia said it regretted to confirm that it had lost contact with the plane.
Air Force spokesman Hadi Tjahjanto said three aircraft, including a surveillance plane, had been dispatched to the area. The Singapore air force and the navy also were searching with two C-130 planes.
Flightradar24, a flight tracking website, said the plane was delivered in September 2008, which would make it six years old. It is not clear if it has any satellite tracking devices on board.
Malaysia-based AirAsia, which has dominated cheap travel in the region for years, flies short routes of just a few hours, connecting large cities of Southeast Asia. However, recently it has tried to expand into long-distance flying through its sister airline AirAsia X.
An official from Indonesia's national search and rescue agency in Medan, North Sumatra monitors computer screens during a search efforts for AirAsia flight QZ8501. Photo / AFP
AirAsia Malaysia owns 49 percent of its subsidiary, AirAsia Indonesia.
Fernandes, who is the face of AirAsia, as well as owner of English football club Queens Park Rangers and an active Twitter user, sent out a tweet saying: "Thank you for all your thoughts and prays. We must stay strong."
He tweeted later that he was heading to Surabaya.
Fernandes stirred controversy earlier this year after incorrectly tweeting that Malaysia Airlines flight 370, now synonymous with one of aviation's enduring mysteries, had landed safely. The wide-bodied Boeing 777 went missing soon after taking off from Kuala Lumpur for Beijing on March 8. It remains missing until this day with 239 people.
Another Malaysia Airlines flight, also a Boeing 777, was shot down over rebel-controlled eastern Ukraine while on a flight from Amsterdam to Kuala Lumpur on July 17. A total of 298 people on board were killed.
William Waldock, an expert on air crash search and rescue with Embry-Riddle Aeronautical University in Prescott, Arizona, cautioned against drawing comparisons to the disappearance of Malaysia flight 370.
"I think we have to let this play out," he said.
"Hopefully, the airplane will get found, and if that happens it will probably be in the next few hours. Until then, we have to reserve judgment."
The circumstances bode well for finding the plane since the intended flight time was less than two hours and there is a known position at which the plane disappeared, he said.
Malaysian Prime Minister Najib Razak, expressed solidarity with AirAsia. In a tweet he said: "Very sad to hear that AirAsia Indonesia QZ8501 is missing. My thoughts are with the families. Malaysia stands ready to help."
A sign board instructing relatives and next-of-kin of the passengers of AirAsia flight QZ8501 to gather at a holding area is placed at the Changi International Airport, Singapore.
President Barack Obama, who was vacationing in Hawaii, was briefed Sunday evening on the plane's disappearance, and White House officials were tracking the situation, the White House said.
The Airbus A320 is a workhorse of modern aviation. Similar to the Boeing 737, it is used to connect cities anywhere from one to five hours apart. There are currently 3,606 A320s in operation worldwide, according to Airbus.
The A320 family of jets, which includes A319 and A321, has a very good safety record, with just 0.14 fatal accidents per million takeoffs, according to a safety study published by Boeing in August.
Family members of passengers of missing Malaysian air carrier AirAsia flight QZ8501 gather at Juanda international airport in Surabaya. Photo / AFP
It's too early to say what might have caused a crash, but the safest part of a trip is when a plane is flying at its cruising elevation. Just 10 percent of fatal crashes from 2004 through 2013 occurred while a plane was in that stage of flight, according to the August Boeing safety report.
Passing through bad weather, such as severe thunderstorms, could have been a factor. Airbus jets are very sophisticated and are able to automatically adjust to wind sheers or other weather disruptions.
However, weather has played a role in past air disasters that occurred at cruise elevation, including the 2009 Air France Flight 447 crash over the Atlantic Ocean.
Another possibility is some type of catastrophic metal fatigue caused by the cycle of pressurization and depressurization associated with each takeoff and landing cycle - something that flight 8501 would have done a lot. Still, metal fatigue is unlikely because this plane is only six years old.
AirAsia has established an Emergency Call Centre at 0622129850801. It is also posting updated information on its website.
