REPUBLIKA.CO.ID, SURABAYA -- The missing AirAsia flight QZ8501 unbelievably made steep climb before it crashed, according to a source close to the probe into what happened said radar data.
The maneuver probably pushed the airplane beyond its limit. The source, who declined to be identified, added that more information was needed to come to a firm conclusion.
"It appears to be beyond the performance envelope of the aircraft," he said.
The plane was traveling at 32,000 feet (9,753 meters) and had asked to fly at 38,000 feet to avoid bad weather. When air traffic controllers granted permission for a rise to 34,000 feet a few minutes later, they received no response.
Online discussion among pilots has centered on unconfirmed secondary radar data from Malaysia that suggested the aircraft was climbing at a speed of 353 knots, about 100 knots too slow, and that it might have stalled.
Some of the bodies recovered so far have been fully clothed, including a flight attendant in her uniform. That could indicate the Airbus was intact when it hit the water and also support the aerodynamic stall theory.
The Indonesian captain, a former air force fighter pilot, had 6,100 flying hours under his belt and the plane last underwent maintenance in mid-November, according to AirAsia Indonesia, which is 49-percent owned by Malaysia-based budget carrier AirAsia.
Three airline disasters involving Malaysian-affiliated carriers in less than a year have dented confidence in the country's aviation industry and spooked travelers. Malaysia Airlines Flight MH370 disappeared in March en route from Kuala Lumpur to Beijing with 239 passengers and crew and has not been found. On July 17, the same airline's Flight MH17 was shot down over Ukraine, killing all 298 people on board.
On board Flight QZ8501 were 155 Indonesians, three South Koreans, and one person each from Singapore, Malaysia and Britain. The co-pilot was French.
The AirAsia group, including affiliates in Thailand, the Philippines and India, had not suffered a crash since its Malaysian budget operations began in 2002.