All 132 people aboard China Eastern Airlines Flight 5735 were killed.
A preliminary report released on Wednesday found no abnormalities before the China Eastern Airlines plane crash last month that killed all 132 people on board, the Civil Aviation Administration of China said.
“There were no abnormalities in radio communication and control command between the crew and air traffic control prior to deviating from cruising altitude,” the report said, before the Boeing 737-800 suddenly plunges into the ground 30,000 feet in the air. .
During a briefing on the report on Wednesday, Chinese aviation officials said their investigation had not found a cause and the crash remained a mystery to investigators who will pursue a full investigation with the help of the US National Transportation Safety Board, US Federal Aviation Administration and other international groups.
The report stated that cabin crew and other maintenance personnel had met all requirements and that the aircraft had been certified airworthy and was up to date with inspections.
He also clarified that there were no dangerous weather forecasts in the area of the accident and that there were no declared dangerous goods on board the plane.
The “black boxes” – the flight data recorder and the cockpit voice recorder – which can tell exactly what was happening on board the plane were badly damaged in the accident, the authorities said. authorities, and investigators are still trying to recover their data to determine what happened.
According to the report, the plane took off at 1:16 p.m. local time and cruised at an altitude of nearly 29,000 feet until about 2:20 p.m. when regional radar found that the plane was beginning to “veer off” from that altitude. . Radar then registered the plane at around 11,000 feet traveling at 117 degrees.
Local air traffic control called the crew, but received no response. Shortly thereafter, the aircraft’s radar signal disappeared.
The crash site in a mountainous area in Teng County, Wuzhou, Guangxi left a crater nearly 500 square feet wide and 10 feet deep. The aircraft wreckage was searched and recovered by investigators.
ABC News’ Gio Benitez and Mark Osborne contributed to this report.