AirAsia plane with 162 on board missing en route to Singapore
AirAsia Group Chief Executive Officer Tony Fernandes at a press conference in Kuala Lumpur on August 11, 2014 (AFP)

Rescuers scoured the Java Sea on Sunday for an AirAsia plane carrying 162 people which went missing in bad weather en route from Indonesia to Singapore, in the third crisis for a Malaysian carrier this year.

Around 11 hours after it disappeared, Indonesian military aircraft had yet to find any sign of the Airbus A320-200 as dusk set in.

The search halted at 5.30pm (1030 GMT) but would resume at 7am Monday, or even earlier if the weather was good, Indonesian transport ministry official Hadi Mustofa told AFP.

Air traffic controllers lost contact with the twin-engine aircraft around an hour after it left Juanda international airport at Surabaya in East Java at 5:20am (2220 GMT Saturday).

Shortly before disappearing, AirAsia said the plane had asked permission from Jakarta air traffic control to deviate from its flight plan and climb above bad weather in an area noted for severe thunderstorms.

The airline, giving a revised breakdown of nationalities, said 155 of those on board Flight QZ8501 were Indonesians, with three South Koreans and one person each from Singapore, Malaysia, Britain and France.

The Frenchman was the co-pilot.

Sixteen of those on board were children and one was an infant.

Two Indonesian air force planes and a helicopter searched the waters around the islands of Bangka and Belitung in the Java Sea, across from Kalimantan on Borneo island.

"We have focused all our strength, from the search and rescue agency, the military, police and help from the community as well as the fishermen," rescue agency chief F.H.B. Soelistyo told a press conference.

He said three ships and three planes from Malaysia would join the search Monday. Singapore had offered a C130 plane and Australia also offered help.

- Anxiety builds -

The aircraft was operated by AirAsia Indonesia, a unit of Malaysian-based AirAsia which dominates Southeast Asia's booming low-cost airline market.

AirAsia's flamboyant boss Tony Fernandes, a former record industry executive who acquired the then-failing airline in 2001, said he was on his way to Surabaya, where most of the passengers are from.

"My only thought(s) are with the passengers and my crew," he added on his Twitter page.

With hard details few and far between, panicked relatives gathered at Singapore's Changi airport.

Indonesian Louis Sidartha, 25, told reporters her fiance was on board the flight.

They had taken separate flights from Surabaya to Singapore, and she said she only found out about the missing aircraft upon arriving in Singapore on a later flight.

In Surabaya hundreds of Indonesians descended on the terminal, hoping for news.

A 45-year-old woman told AFP that she had six family members on the plane.

"They were going to Singapore for a holiday," she said.

"They have always flown with AirAsia and there was no problem. I am very worried that the plane might have crashed."

Indonesia's President Joko Widodo said his nation was "praying for the safety" of those onboard.

His country, a vast archipelago with poor land transport infrastructure, has seen an explosive growth in low-cost air travel over recent years.

But the air industry has been blighted by poor safety standards in an area that also experiences extreme weather.

AirAsia said the missing jet last underwent maintenance on November 16. The company has never suffered a fatal accident.

An official from Indonesia's transport ministry said the pilot asked to ascend by 6,000 feet to 38,000 feet to avoid heavy clouds.

"The plane is in good condition but the weather is not so good," Djoko Murjatmodjo told a press conference at Jakarta's airport, addressing reports of severe storms in the area where the jet went missing.

Climbing to dodge large rain clouds is a standard procedure for aircraft in these conditions.

"What happens after that is a question mark," according to Indonesian-based aviation analyst Dudi Sudibyo.

The plane's disappearance comes at the end of a disastrous year for Malaysian aviation.

Malaysia Airlines Flight MH370, carrying 239 people, vanished in March after inexplicably diverting from its Kuala Lumpur-Beijing course. No trace of it has been found.

Another Malaysia Airlines plane went down in July in rebellion-torn eastern Ukraine, killing all 298 aboard. It was believed to have been hit by a surface-to-air missile.

AirAsia has seen spectacular success and aggressive growth under Fernandes' low-cost, low-overheads model.

While its rival Malaysia Airlines faces potential collapse after the two disasters this year, AirAsia this month confirmed its order of 55 A330-900neo passenger planes at a list price of $15 billion.