PILOTS onboard a doomed Chinese passenger plane may have passed out as the aircraft began to plummet, before briefly regaining consciousness as they tried to save it, an expert has claimed.
Rescuers have found no sign of any survivors after horror video showed the passenger jet going into a nosedive just before the sickening crash.
More than 600 emergency responders are said to be at the crash scene in a remote location following Monday’s crash.
Flight MU5735 left the city of Kunming at 1.11pm local time (5.11am GMT) and was scheduled to arrive in Guangzhou at 3.05pm.
Just as the plane was due to begin its descent, it suddenly lost altitude rapidly, dropping thousands of feet in a couple of minutes.
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It briefly regained height for a few seconds at around 9,000 feet, before crashing to the ground at an estimated 350 miles an hour in a hilly wooded area not far from the city of Wuzhou.
Boeing 737-800s have an excellent safety record, as does China’s aviation industry.
The country’s last major plane accident came in August 2010 when a flight from Harbin crashed in northeast Yichun during foggy weather, killing 42 people.
China Eastern, one of the country’s big three airlines, has grounded all its Boeing 737-800s as a precaution and set up a hotline for people seeking any information about those on board.
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In a statement, it expressed “its deep condolences for the passengers and crew members who died”.
The Boeing 737-800 is not the same as the Boeing 737 MAX, which was involved in two fatal accidents in the space of a few months.
A fault with the plane’s Manouevering Characteristics Augmentation System (MCAS), an inbuilt flight stabilisation program, caused two crashes, Lion Air Flight 610 and Ethiopian Airlines Flight 302, killing a total of 346 people.
Speaking to The Sun Online, aviation expert Sally Gethin explained that the circumstances behind today’s shocking crash are very different to those surrounding the Boeing 737 MAX crashes.
“The 737-800 has a particularly good safety record,” she said. “There are thousands of them operating around the world, about 1,000 in China alone.
“But the fact that China Eastern Airlines is grounding all of those planes from the fleet as a precaution suggests they’re concerned about the safety of that aircraft.”
Although Ms Gethin maintained it is “too soon to speculate” about the exact cause of the crash, she said that the plane’s rapid descent from a cruising altitude of 29,000 feet could have been down to a malfunction with the jet’s tail.
She said: “If the tail sheared off before the nosedive, the plane would lose all aerodynamics – it can’t operate properly without the rudder in the tail. Nothing can be ruled out at this stage.”
The sheer speed of the plane’s descent, as shown on data put together by Flight Radar 24, suggests to Gethin that something sudden happened at 29,000 feet.
“This doesn’t sound like an escalating issue that the crew were battling with”.
Sources in China report that the plane had three pilots on its fateful last flight, two extremely experienced, and one trainee.
The pilot reportedly had around 7,000 hours of flight experience, while the co-pilot had 30,000.
Having a more experienced co-pilot than pilot already strikes Gethin as “unusual”, although no suggestion has been given as to why this may have been the case.
In the jumpseat was a trainee pilot with just a few hundred hours of flying experience.
Gethin says the nine crew and 123 passengers would have faced a horror two-minute plunge, as the g-force sent the blood rushing to their heads and knocked them out.
But the graph, which shows the plane’s altitude steady briefly, suggests to her that there was a “10 to 20-second spell where one or more of the pilots regained consciousness and tried to save the plane,” before it went into a sickening death plunge.
Video shared widely shows the plane in that final nosedive, which preliminary flight data suggests began at around 8 to 9,000 feet.
All of those on board “would have been unconscious” for this final plunge, Gethin suggests.
If the tail sheared off before the nosedive, the plane would lose all aerodynamics
Although she is quick to stress that there is no suggestion so far of “foul play” or any sort of deliberate crash, Gethin says pilots can experience what is known as the “startle effect”.
She explained: “Pilots get a huge amount of training, much of it in simulators. But in the real world, they can get overwhelmed or disorientated by sudden events.
“This is known as the startle effect, and it is every hard to train for that.
“Even experienced pilots can be caught off guard and that’s when they can make poor judgements. Now there are efforts to recognise that and offer additional training.”
The location where the plane’s descent began is the same point where flight MU5735 began its descent – also from 29100 feet – the day before the accident, suggesting something went wrong immediately after the plane came out of cruise.
Most plane crashes occur either during takeoff and landing, making the circumstances behind the incident in southern China even more mysterious.
Gethin adds planes coming down in a nosedive is almost unheard of, as they are far more aerodynamic than helicopters, and even if they lose power, they should still be possible to land.
She raises the example of US Airways Flight 1549 when a pilot safely landed his plane on New York’s Hudson River after birds flew into both engines.
Pillot Chesley Sullenberger was able to glide safely onto the water without power, saving the lives of all 155 on board.
But flight MU5735 came vertically down, showing a so-called “stalled flight” was unsuccessful, or not even attempted.
Gethin says any number of issues could have affected the plane, whether it was a “small fire on board,” or a wiring issue.
However, video shows the plane’s fuselage was intact when it went into a nosedive.
Weather is a final factor which must be considered, Gethin went on.
“The plane came down in mountainous terrain known for poor weather,” she said.
“It would be prone for a micro weather event. A freak incident known as a microburst – a localised downdraft within a thunderstorm – can cause serious disruption to the pilots.
“Also, if visibility was poor due to weather and then the instruments started to fail, that would be very difficult, as the pilots lose spatial orientation.”
China Eastern is responsible for the maintenance of the plane. It is part of Sky Team Airline Alliance, a group formed with many western airlines.
Although this isn’t damaging for Boeing “at face value,” Gethin adds that “it’s true Boeing doesn’t have a great track record on this in recent years.
“Boeing has seen a lot of changes at the top since the 737 MAX scandal. So has the Federal Aviation Authority, after accusations of collusion with Boeing.
“The company has to prove that it can be trusted with design and modifications, as it was found to be at fault over the MAX.
“There is no doubt that the Brand of Boeing was very damaged. If this was a design flaw with the 737-800, we would probably have seen evidence by now, as so many are in operation.
“Boeing needs to redeem itself.”
In a statement Monday evening, Boeing said: “Boeing is in contact with the U.S. National Transportation Safety Board and our technical experts are prepared to assist with the investigation led by the Civil Aviation Administration of China.
“Our thoughts are with the passengers and crew of China Eastern Airlines Flight MU 5735. We are working with our airline customers and are ready to support them.”
Rescue efforts have continued into the night in Guangxi at the crash site.
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A number of staff from Wuzhou People’s Hospital are on standby amid the frantic search for survivors.
China’s Vice Premier Liu He and Guangxi State Councilor Wang Yong are guiding the rescue and investigation following the crash, as reported by Chinese state media.