Data received by air traffic control showed the aircraft climbing too fast before crashing into the Java Sea on December 28, Indonesia'sTransport Minister Ignasius Jonan told parliament Tuesday.
But the unusual readings might have been caused by a broken pitot tube, an instrument used to determine airspeed, said Wisnu Darjono,director of safety and standards at AirNav Indonesia, the state-owned air navigation agency.
"Maybe the aircraft did climb that fast but maybe it didn't," he told dpa.The pitot tube is part of several pressure-based sensors measuring airspeed and altitude.
That information is then radioed back to radar stations on the ground to assist air traffic control."Mr Jonan cited information from automatic dependent surveillance-broadcast," he said, referring to data packages received by air traffic control before the crash.
"It is true but we cannot know for sure until we read the content of the flight data recorder," Wisnu said. Flight QZ8501 was midway from Surabaya, Indonesia, to Singapore when it went down with 162 people on board.
Jonan said data indicated a climb rate of 6,000 feet per minute,compared with a normal rate of 1,000 or 2,000 feet per minute.Investigators said an initial analysis of cockpit voice recordings found no indications of foul play.
Experts have said weather was likely to be a factor.So far, 53 bodies have been recovered from the sea and attempts were being made to lift the aircraft fuselage to the surface.