China reveals more details about the MU5735 air crash

An investigation team of The State Council, China’s cabinet, held a press conference on Monday evening to reveal more details about the China Eastern Airlines plane MU5735 air crash, including that the ground surveillance system failed to respond to multiple calls during the crash.

A Boeing 737-800 aircraft carrying 132 passengers and nine crew members crashed in Wuzhou County, South China’s Guangxi Zhuang Autonomous Region on March 21.

The costly crash ended 4,226 consecutive days of safe operation for China’s civil aviation since the Yichun air crash on Aug. 24, 2010, and is sure to have an even worse impact on China’s airlines, which have been recovering from the COVID-19 pandemic.

On March 22, airline stocks tumbled, with China Eastern airlines plunging more than 7% at one point.

As of now, the black box of flight data is still being searched, and the investigation surrounding this tragedy may take a long time, but some of the flight information made public may help us to get closer to the truth from all kinds of unserious, irresponsible rumors and even “conspiracy theories.”

According to professional interpretation of adS-B and Flightradar24 real-time flight data, the plane had been cruising at an altitude of about 8,869 meters before the crash. At 14:19 PM, the plane suddenly began to descend from its cruising altitude and its speed began to decrease from about 845km/h. Within two minutes, it lost signal and was filmed plummeting at high speed in a vertical dive in Teng county, Wuzhou, Guangxi province.

In the interim, the most critical information was that the flight resumed its climb at 7,400 feet (2,255.52 meters) before plummeting again at approximately 8,600 feet (2,621.28 meters) and vanished at 1,333.5 meters at 14:22 a.m.

Does this mean that the pilot acted in a remedial way during the crash, and that the breakup of the fuselage did not cause the plane to accelerate from nearly 9 kilometers to more than 2,000 meters — the plane did not break up at the beginning.

It seems that the images taken bear this out.

According to Baidu Encyclopedia, mid-air disintegration (commonly known as falling apart) refers to the rupture of the fuselage of an aircraft (or other aircraft) caused by structural damage due to various reasons, such as airflow, impact, explosion, missile shooting down, improper operation, and exceeding the maximum overload. Because the cabin is pressurized, the pressure inside can tear the plane apart, breaking it into pieces, much like a balloon bursting.

According to this explanation, we seem to be able to rule it out.

In fact, the causes of air crashes are nothing more than a few things: operational error, mechanical failure, extreme weather, missile attacks and accidental collisions.

For now, the suspicion of human error, including deliberate error, cannot be ruled out.

Mechanical failure, including the extreme loss of power of both engines at the same time, professionals believe that it is basically impossible to cause non-glide vertical fall, so the engine problem can be basically ruled out, but what about the mechanical properties of other parts?

Extreme weather, the meteorological department has denied, but the troposphere (at an average altitude of 10km) is so complex that undetected extreme weather cannot be completely ruled out.

Missile attack, flight over domestic route, clear air traffic, the possibility is basically ruled out.

Accidental collision. So far, no reports of other aircraft in the same airspace at the same time.

In short, the cause of the accident still needs more evidence, especially the “black box” data support.

About the Boeing 737 NG
Boeing’s 737 is the world’s best-selling airliner, with more than 10,000 made.

China Eastern Airlines Boeing 737-800 has 162 seats (up to 189) and uses CFM56 engines. It belongs to the third Generation of Boeing 737 NG New Generation aircraft.

China Eastern airlines currently has 108 Boeing 737-800s, the largest number of models in service after Airbus A320-200, mostly carrying domestic and short-haul international routes.

China Eastern airlines has grounded all of its flights because of the incident.

In fact, as early as late September 2019, while retrofitting a 737-800BCF used by a Chinese company, operators found structural cracks in the Fork “Pickle Fork,” which connects the fuselage to the wing. Although cracks occur frequently, But if long-term development leads to mid-air disintegration.

According to public reports, China Eastern airlines is the first Chinese MRO to obtain in-depth replacement and repair of the 737 NG fork technology, which has been approved by Boeing. According to the report, after more than 40 days of struggle, China Eastern Technologies successfully completed the deep repair of a Boeing B737NG aircraft at the Yunnan Hangar of China Eastern Airlines on December 23, 2019, becoming the first aviation MRO to complete the project in China.

The report also mentioned that the fork is the fuselage and wing connecting component, is an important force bearing component. Because the replacement of this part involves many important areas such as cabin, wheel well, wing and central fuel tank, it is extremely difficult to maintain.

In addition, like the 737 MAX, Boeing’s fourth-generation 737 banned by China, the entire 737 NG has been added with a neglected MCAS system. The stall and roll protection system is designed to prevent the aircraft from stalling or tumbling or flying backwards due to excessive nose elevation. However, when this system is inadvertently triggered, even if the autopilot is removed, the aircraft will fall for nearly 10 seconds, and the aircraft is difficult to control.

Questions persist about the 737’s design flaws, particularly the rudder, but it is too early to blame mechanical problems.

According to Boeing’s website, Boeing has delivered a total of 1,000 737 NG aircraft to Chinese customers covering almost all major Chinese airlines. Such as Air China, East China Sea Airlines, China Eastern Airlines, China Southern Airlines, Hainan Airlines, Hebei Airlines, Kunming Airlines, Ruili Airlines, Shandong Airlines, Shanghai Airlines, Shenzhen Airlines, Xiamen Airlines and Bank of China Aviation Leasing, Bank of Communications Leasing, Bank of China Aviation Financial leasing, ICBC Leasing and so on.

And if the CAAC decides to suspend all NG flights, it will have a huge impact on The Chinese aviation industry.

Search and rescue, may the miracle come!