An unexplained 30 seconds from China Eastern's doomed MU5735 flight has left experts baffled.
The China Eastern Airlines Boeing 737-800 plummeted from the sky in the country's southern province of Guangxi on Monday carrying 132 people.
Emergency personnel are continuing to scour the wreckage but there are believed to be no survivors.
As mystery surrounds why the aircraft fell from the sky with such speed and so suddenly, aviation experts have said there appears to be 30 seconds unaccounted for - from the final 150 seconds recorded.
Data from the doomed journey appears to show the plane rapidly falling from an altitude of 29,100ft (8869m) to 9075ft (2766m) in two minutes and 15 seconds.
FlightRadar24 detected the plane then appeared to stabilise before losing altitude once again.
The period of stabilisation and then secondary fall has left experts stumped as to what may have occurred.
Aviation expert Neil Hansford told 9NEWS: "It is unlikely, unless it was absolutely catastrophic like the wings falling off, for it to have fallen from the sky in the way that it did.
"This has gone straight down. It’s likely when you go through the causes it has been hit in flight with military ordinance or there’s been a pilot intervention or a collision."
Hansford also claimed it was unlikely the sudden and rapid nosedive could be down to a technical fault - but was more likely due to 'human-induced activity'.
He added: "It is very unlikely the pilot passed out as the non-flying pilot would have been able to very safely take over the flying and land the aircraft.
"Likely scenarios include pilot suicide, aircraft mid-air collision with a military aircraft - that don't have transponders like civil aircrafts.
"My tipping is a human-induced event or brought down by rogue missile. Debris looks like MH117 over Ukraine and the Chinese are providing too much information this time which is uncharacteristic."
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".
