Around 11 hours after it disappeared - approximately 5 pm local time on Sunday - Indonesian air force jets had yet to find any signs of the Airbus A320-200, with dusk fast approaching and fuel running low.
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 5:20 am (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 said 156 of those on board Flight QZ8501 were Indonesians, with three South Koreans and one person each from Singapore, Malaysia and France.
Britain later said one of its citizens was onboard the jet. It was not yet confirmed whether they had dual nationality.
There were 138 adult passengers, 16 children and an infant, in addition to five cabin crew and the pilot and co-pilot, who is believed to be French.
Two Indonesia air force planes and a helicopter were searching the waters around the islands of Bangka and Belitung in the Java Sea, near Kalimanten island.
"We have not been able to visually detect any signs," air force spokesman Hadi Cahyanto told AFP, adding search boats were still on their way to the area, around halfway along the missing aircraft's expected flight path.
"The weather is quite good. However, we only have a few hours more to go as our fuel will run out. By then it will also get dark... the planes will have to return to Jakarta."
A Singaporean C-130 military transport aircraft was also deployed, after Indonesia accepted help from its Southeast Asian neighbour, while Malaysia said it had committed "military assets" to the search.
The aircraft was operated by AirAsia Indonesia, a unit of Malaysian-based AirAsia which dominates Southeast Asia's booming low-cost airline market.