A cockpit windscreen of a Sichuan Airlines jet was ripped out at 32,000ft on Monday. /CCTV Photo
The shattered cockpit windshield was an import and had no record of failure, maintenance or replacement, said the Civil Aviation Administration of China (CAAC) at a press conference on Tuesday afternoon about the preliminary investigation into the Sichuan Airlines incident.
Flight 3U8633, which took off from southwest China's Chongqing Municipality on Monday, was forced to make an emergency landing in Chengdu before it could arrive at its destination in Lhasa City in the Tibet Autonomous Region when the windshield broke mid-flight.
An investigation team was soon set up and started their work on Monday morning.
The initial investigation showed that the incident was caused by the shattered cockpit windshield which led to the decompression and sharp descent of the aircraft.
"According to the current investigation, the cockpit windshield at the front-right side had peeled off, and one third of the flight control unit at the right side also fell off," said Zeng Fan'ge, deputy director of the Aviation Safety Management Office of the CAAC Southwest Regional Administration.
The aircraft, with its number of A319/B-6419, was built by the European planemaker Airbus, and commissioned to the Sichuan Airlines on July 26, 2011.
Airbus has sent a technical team to provide support for the investigation.
The pilots and crew were praised by their heroics and professionalism. "The measures taken by the crew during the whole incident were quick and effective, ensuring a successful landing in Chengdu," said Zeng.
Potential causes for the shattered windshield
There are several potential reasons that may have led to the windshield breaking, said Zhang Qihuan, a researcher from the Institute of Air & Space Law of China's University of Political Science and Law.
The first might be the collision with an external object, like a bird. The second could be a malfunction with the windshield's anti-icing system. An inspection not comprehensive enough to detect any cracks in the glass could be the third cause. And the fourth may be the quality of the glass itself, Zhang said.
The investigation is still underway.