The cause of the crash of a Chinese airliner on the 21st of last month is still unknown.
Although both black boxes were recovered from the site, Chinese authorities revealed that the black boxes were severely damaged, raising the possibility that the accident itself could end in a labyrinth.
At the time of the accident, 123 passengers and 9 crew members were on the plane.
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"Accident airliner crashed at 1,010 km/h in the direction of 117"
The Civil Aviation Administration of China (Civil Aviation Administration), which is investigating the crash, released a preliminary investigation report on April 20, a month after the accident.
This is in accordance with the International Civil Aviation Convention, which requires that preliminary reports be submitted to the International Civil Aviation Organization within 30 days of the accident.
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Through this announcement, it was confirmed once again that the plane plunged down at the time of the accident.
According to the Civil Aviation Administration, the China Eastern Airlines MU5735 passenger plane that crashed took off from Kunming Airport in Yunnan Province at 1:16 pm and climbed to a cruising altitude of 8,900m 11 minutes later.
It was 1 hour and 4 minutes after takeoff that the plane deviated from altitude.
At 2:20 PM, an altitude departure warning sounded in the control tower.
The control tower called immediately, but there was no response from the airliner.
The last flight recorded on radar was 2:21:40, and the plane at that time had an altitude of 3,380 m, a speed of 1,010 km/h, and a direction of navigation of 117 degrees.
The airliner has since disappeared from radar.
In less than a minute, the altitude dropped 5,520m from 8,900m to 3,380m.
A puddle with a width of 45 m2 and a depth of 2.7 m was formed in the place where the passenger plane fell.
Earlier, CCTV of a company near the crash site captured a scene of a passenger plane falling almost vertically.
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Passenger plane wreckage found 12 kilometers from the crash site
One of the new findings is that the wreckage of the plane was found 12 kilometers from the crash site.
The wreckage found is a part of the right wing, and some Chinese netizens have raised suspicions about whether the airliner may have exploded in mid-air.
Experts have started to evolve the suspicion.
In an interview with Chinese media Pengpai, secretary-general of the Henan Aviation Association's expert committee, Qiao Sanxun, said, "This part is a device that increases the efficiency of the wing, and there is no need to over-interpret it."
"Since it was falling at a very high speed of 1010 km/h, it could be that the parts were overloaded and could not withstand the impact and fell off the body," he explained.
Furthermore, he added, "Due to the fact that the vertical tail wings, rudder, left and right engines, left and right wings, and parts inside the cockpit were found at the site, it cannot be ruled out that the aircraft body was disassembled in mid-air during the crash."
"Severe damage to the black box... The cause of the crash may not be found within 2 years"
Regarding the cause of the accident, the Civil Aviation Administration said that the pilot, crew and repair personnel of the aircraft all met the qualifications.
He said there were no abnormalities in aircraft malfunctions, navigation systems, or radar equipment before flight.
The weather conditions were also free from risk factors such as turbulence or lightning, and the last time the airliner communicated with the control tower before leaving the cruising altitude was 2:16 pm, and there was no problem in communication.
No cargo was declared as dangerous goods on board.
If so, why the accident happened, this is a topic that further amplifies the question of the cause of the accident.
This accident is considered a rare accident due to the fact that the airliner did not glide at an angle and fell almost vertically, and that the pilots did not respond to several calls from the control tower.
At that time, there was one captain and two pilots in the cockpit, and there were three people on board.
The idea is that the co-pilot may have taken extreme actions.
However, the Chinese authorities concluded that nothing was confirmed and that it was a rumor.
Chinese authorities are putting their hopes on the two black boxes recovered from the scene: a 'flight data recorder (FDR)' and a 'cockpit voice recorder (CVR)', but it is unknown whether the cause of the accident will be revealed.
The two black boxes were discovered 2 days and 6 days after the accident, respectively.
It's been almost a month, and the Chinese authorities are still repeating the word "data recovery and analysis is in progress".
In this preliminary report, the Civil Aviation Administration said, "
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"Usually, the preliminary report does not include an analysis of the cause and conclusion of the accident," said Secretary-General Qiao Shanxen.
He also said that "the Civil Aviation Bureau will come up with a reasonable view."
However, the opinion of the Minhangguk is different.
"Historically, aviation accident investigations have required a long process," said the head of the relevant department at the Civil Aviation Administration in an interview with the state-run Xinhua News Agency.
He explained that the final report of the 2009 Air France accident was not released until three years later, and the investigation into the Yichun airliner accident in China took almost two years.
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The Yichun airliner accident refers to an accident in August 2010 when a passenger plane departing from Harbin, Heilongjiang Province, attempted to land at its destination, Yichun, and crashed into the ground.
44 of the 96 people on board died, but Chinese authorities concluded that 'the control tower informed that the weather conditions were bad, but the pilot forced the landing to cause an accident'.
At that time, the fact that the weather conditions were bad, the communication history between the passenger plane and the control tower, and the black box records were immediately revealed, but it took nearly two years to write the final report.
It also means that we don't know when the final report of the incident will be released.