A Boeing 737-800 aircraft of the China Eastern Airlines' Yunnan branch.
No abnormality has been found pertaining to the crew, aircraft, cargo, flying route, equipment or weather on the ill-fated China Eastern flight MU5735 that crashed in south China last month, according to the initial investigation report released on Wednesday.
Data restoration and analysis are still ongoing on the two black box recorders, which were severely damaged during the crash, according to the Civil Aviation Administration of China.
"The technical investigation team will focus on wreckage recognition, classification and inspection, along with flying data analysis as well as necessary experiments and verification, for the cause of the accident," the CAAC announced.
According to the Chicago Convention on International Civil Aviation, investigators will submit a preliminary investigation report to the International Civil Aviation Organization, in both Chinese and English, within 30 days.
The initial report normally only has the facts of the accident, with no analysis or conclusions on the cause of the accident.
The flight was en route from Kunming in southwest China's Yunnan Province to Guangzhou in southern Guangdong Province when it crashed in Tengxian County of Wuzhou City in the Guangxi Zhuang Autonomous Region on March 21.
Flight MU5735 had 123 passengers onboard along with nine crew – three pilots, five flight attendants and a security guard. All 132 people onboard died.
Rescuers found the two black box recorders within a week after the accident and identified the DNA of all victims within eight days.
According to the CAAC report, the aircraft took off from Kunming Changshui International Airport at 1:16pm and ascended to the cruise altitude of 8,900 meters at 1:27pm.
At 2:17pm, it entered the jurisdiction of the Guangzhou air traffic controller, which received a warning of "altitude deviation" on radar at 2:20pm.
The ATC then called the pilots but received no answer.
The last record of the aircraft on the radar showed it was flying at an altitude of 3,380 meters with a speed of 1,010 kilometers per hour at 2:21pm, when its signal disappeared shortly afterward.
A 45-square-meter and 2.7-meter-deep pit was found in the valley of Molang Village in the county's Langnan Town, which was later confirmed as the main crash site. The forest and plants nearby were burnt.
The right winglet of the plane was found about 12 kilometers from the main crash site. Other key wreckage found near the site included the horizontal stabilizer, vertical stabilizer, left and right engines, left and right wings, fuselage parts, landing gear and cockpit.
The pilots, flight attendants and repairers were qualified, with the aircraft boasting an airworthiness certificate and latest maintenance.
No malfunction, dangerous cargo or inclement weather was reported. The navigation and monitoring system along the flying route also operated normally.
Before the aircraft deviated from its normal altitude, the air-ground communications were normal. The last communication was made at 2:16pm, according to the report.
Editor: Cai Wenjun