Pilots aboard a doomed Chinese passenger plane may have lost consciousness as the aircraft hurtled towards the ground before briefly waking up, an expert has said.
The China Eastern Airlines Boeing 737-800 came down in the country's southern province of Guangxi on Monday carrying 132 people.
Emergency personnel are continuing to scour the wreckage but rescuers have found no sign of any survivors.
A horror video shows the plane going into a nosedive prior to the crash.
Flight MU5735 had departed the city of Kunming at 1.11pm local time (5.11am GMT) and was due to arrive in Guangzhou at 3.05pm.
But as it prepared to descend, the aircraft lost altitude and dropped thousands of feet in seconds.
Despite momentarily regaining height at close to 9,000ft it hit the ground at an estimated 350mph in a hilly woodland area near the city of Wuzhou.
China Eastern has grounded all of its Boeing 737-800s as a precaution.
In a statement, the airline - one of the three biggest in China - expressed "its deep condolences for the passengers and crew members who died".
Aviation expert Sally Gethin said the circumstances behind Monday's crash are different to those leading up to the Boeing 737 MAX crashes of the Lion Air Flight 610 and Ethiopian Airlines Flight 302, which occurred just months apart.
A total of 346 people were killed after the planes' MCAS, an inbuilt flight stabilisation system, malfunctioned.
Ms Gethin told The Sun the 737-800 has a "particularly good safety record" but the grounding of the model - of which there are thousands - suggests the airline are "concerned".
She said while it is "too soon" to speculate about the cause of the crash, she suggested it could have been a malfunction of the jet's tail.
Ms Gethin went on to say 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 unconscious.
However, the flight graph shows the aircraft steadied briefly, suggesting there was a "10 to 20-second spell where one or more of the pilots regained consciousness and tried to save the plane".
She added that everyone on board would have been unconscious during the final plunge.
Ms Gethin said if a plane loses power it is usually possible for it to land and for an aircraft like that to nose dive is almost unheard of.
She suggested there is some possibility a freak weather occurrence in the mountainous terrain may have caused sudden disruption to the pilots.
