CAAC Releases Preliminary Report on China Eastern Airlines MU5735 Crash

The team investigating the crash of China Eastern Airlines Flight MU5735 has recovered its flight data recorder, pictured here. (Photo, courtesy of Xinhua News Agency)

The Civil Aviation Administration of China (CAAC) published its preliminary report regarding an ongoing investigation into what caused a Boeing 737-800—flight MU5735—operated by China Eastern Airlines to crash during a March 21 flight from Kunming to Guangzhou.

CAAC's preliminary report provides very few details about the crash, information downloaded from the flight data and cockpit voice recorders or any significant updates at all about the investigation beyond what has already been publicly released. As previously confirmed by the agency, the aircraft crashed in Guangxi new the Wuzhou City, Zhuang Autonomous Region, killing all 132 flight crew members and passengers onboard.

According to the report, when an air traffic controller tried to reach the flight crew once the aircraft started dangerously losing altitude, they received no reply. Flight tracking provider FlightRadar24’s replay of the flight shows that the aircraft reached an altitude of about 29,100 feet before taking a sharp nose dive into the ground.

"At 14:21:40, the last recorded aircraft information by the radar was: standard pressure altitude of 3,380 meters, ground speed of 1,010 km/h, and heading of 117 degrees. Subsequently, the radar signal disappeared," CAAC writes in the report.

CAAC's report also found no major defects within the airworthiness condition of the aircraft and no unique system or component issues from a review of its maintenance history. None of the recorded communications between the pilots and air traffic controllers that occurred prior to controllers losing contact were found to be abnormal either.

The National Transportation Safety Board (NTSB) started assisting CAAC in its investigation into the crash of MU5735 on April 1, and has not released any updates or statements on its involvement in the investigation since then.

"Under the provisions of the International Civil Aviation Organization Annex 13, the NTSB is participating in the CAAC’s investigation of the China Eastern B-737 accident.  Those provisions also stipulate that the authority in charge of the investigation, in this case the CAAC, release all investigative information," a representative for the NTSB told Avionics International in an emailed statement.

The ongoing investigation will continue to focus on several aspects of the crash "as wreck identification, classification and inspection, flight data analysis, and necessary experimental verification in accordance with relevant procedures, and scientifically and rigorously identify the cause of the accident," according to CAAC.

Receive the latest avionics news right to your inbox