Pilot behavior, weather among possible factors in airliner mystery

AirAsia Flights 8501 asked for permission to climb when the plan encountered bad weather over the Java Sea.

The request was made at 6:12 a.m. local time, while the plane was flying at 32,000 feet. The pilot wanted to go to 38,000 feet t0 "avoid the clouds." But an Indonesian transport official said that request was denied because of "traffic."

At about 6:18 a.m., radar contact was lost. Experts say weather may have played a role in the disappearance.

"Weather can be a serious factor in many aviation accidents, but it is never the single cause of what ultimately created the accident," said Mark Rosenker, former chairman of the National Transportation Safety Board. "Accidents are always a chain of events."

In addition to weather, investigators will also look at air speed -- if the plane was going too slow; mechanical failure; and how the pilots may have reacted to an emergency onboard.

AirAsia said the captain had more than 6,000 hours flying the Airbus A-320. The co-pilot had 2,200 hours of flying experience with the airline, and Air Asia itself has a good safety record.

The search for Air Asia 8501 comes nine months after Malaysia Air Flight 370 dropped off radar with 299 people on board. Investigators believe that plane was deliberately turned off course and ended up in the vast and deep southern Indian Ocean off the coast of Australia.

The search so far for the AirAsia flight has been focused on areas around the Java Sea where the waters aren't as deep, around 150 feet.

Aviation sources say the plane was equipped with the flight data tracking system known as ACARS. It can feed diagnostic information about the plane to the ground in real time. What is not clear is if flight 8501 was using that system at the time of its disappearance.