Search area expanded in hunt for AirAsia plane

A member of an Indonesian Hercules C130 aircrew watches through a window while monitoring the Belitung Timur sea during search operations for AirAsia flight QZ8501 near Belitung island, December 29, 2014 in this photo taken by Antara Foto.[Photo/Agencies]

Based on the plane's last known coordinates, the aircraft probably crashed into the water and "is at the bottom of the sea," Indonesia search-and-rescue chief Henry Bambang Soelistyo said. Still, searchers planned to expand their efforts onto land on Tuesday.

The last communication from the cockpit to air traffic control was a request by one of the pilots to climb from 32,000 feet (9,754 meters) to 38,000 feet (11,582 meters) because of the weather. The tower was not able to immediately comply because of the other planes, said Bambang Tjahjono, director of the state-owned company in charge of air traffic control.

The twin-engine plane was last seen on radar four minutes after the final communication.

A storm alone isn't going to bring down a modern plane designed to withstand severe weather. But weather paired with a pilot error or a mechanical failure could be disastrous.

Pilots rely on sophisticated weather-radar systems that include a dashboard display of storms and clouds, as well as reports from other crews, to steer around dangerous weather.

"A lot more information is available to pilots in the cockpit about weather than it ever was," said Deborah Hersman, former chairman of the US National Transportation Safety Board. But the technology has limits and sometimes information about storms "can be a little bit stale."

Jakarta's air force base commander, Rear Marshal Dwi Putranto, said an Australian Orion aircraft had detected "suspicious" objects near an island about 100 miles (160 kilometers) off central Kalimantan. That's about 700 miles (1,120 kilometers) from where the plane lost contact, but within Monday's greatly expanded search area.

"However, we cannot be sure whether it is part of the missing AirAsia plane," Putranto said.

Air Force spokesman Rear Marshal Hadi Tjahnanto told MetroTV that an Indonesian helicopter spotted two oil patches in the Java Sea east of Belitung island, much closer to where the plane lost contact. He said oil samples would be collected and analyzed.