The actions and motivations of one man in the disappearance of flight MH370 have proven central in any attempt to solve the 10-year-old mystery.
That is the doomed plane’s captain, Zaharie Ahmad Shah.
The Malaysian Airlines Boeing 777 vanished in March, 2014, with veteran chief pilot Zaharie dying among the 238 passengers and crew, including six Australians, after it departed from Kuala Lumpur.
READ MORE: Malaysian government indicates potential new search for MH370
The final contact with the plane happened when it entered Vietnamese airspace in the early hours of March 8, 2014, after which the flight suddenly changed course.
The message “All right, good night” was received by Kuala Lumpur air traffic controllers just before the Boeing-777 disappeared from their radar and diverted from its scheduled flightpath to Beijing.
Investigators have maintained somebody must have been in charge of the aircraft when it made this departure from its intended course.
Since then Zaharie has been the subject of relentless scrutiny, with claims his behaviour while flying the plane was affected by extreme stress, deep financial problems or he was even involved in a plot to crash it and take his own life.
But his family and many friends have vigorously defended him against theories he deliberately caused the disappearance of MH370 and insist he has become a scapegoat for the tragedy.
Who was Zaharie Ahmad Shah?
Zaharie was the second-youngest of nine children from a humble family in a village. He won a scholarship to university but instead chose to pursue a career in aviation.
“He was a young boy, 14 or 15, when he fell in love with airplanes,” his sister Sakinab Shah told CNN in 2016.
Her brother completed his pilot’s licence in the Philippines and in 1981 joined Malaysian Air Systems (MAS), where he notched up more than 18,000 hours flying time.
Sakinab told the BBC in 2016 her brother had “no money problems, no mental health problems, no marriage problems, no drug or alcohol problems, no history of odd behaviour” at the time of MH370’s disappearance.
But some friends told other media outlets Zaharie was feeling depressed and lonely in the days leading up to the plane’s disappearance after his wife told him she was leaving their marriage.
READ MORE: Debunking the MH370 conspiracy theories
Home flight simulator
Theories that Zaharie was behind the plane’s disappearance gained fresh momentum in mid-2016 when deleted files on his home flight simulator were recovered by the FBI.
They reportedly revealed he had plotted a course into the deep southern Indian Ocean – a course that closely matched the final flight MH370 is thought to have taken.
Analysis by the Australian Transport Safety Bureau found MH370 likely reached an area over the Indian Ocean designated the “7th arc” when the plane probably ran out of fuel and began a descent into the sea.
Investigators said the simulator files had been created just weeks before the jet disappeared.
Australian and Malaysian officials later insisted the flight simulator data proved little and doesn’t reveal anything about what happened aboard MH370.
READ MORE: The two spots where experts believe MH370 can be found
The said in 2016 it only showed a “possibility” of planning and provided a “piece of information”.
But in 2021, a study by aerospace engineer Richard Godfrey based on radio signals that cover the Earth suggested Zaharie made numerous turns to avoid detection before the passenger jet took its final, fatal course.
The following year Godfrey and American MH370 wreckage hunter Blaine Gibson pointed to analysis of wreckage from the doomed jet that washed up off Madagascar that backed theories the aircraft was crashed deliberately.
They suggested the landing gear debris was likely penetrated from the inside by the aircraft’s engines breaking up on impact. This showed the landing gear probably being down when the plane crashed into the Indian Ocean 10 years ago, they said.
During emergency landings on water, pilots are trained to retract a plane’s landing gear and lower the flaps to ensure a low-speed and controlled ditching.
Rogue pilot theories
Writers, aviation experts and commentators about MH370 have put forward various theories about how Zaharie could have been responsible for the plane’s disappearance.
Some have speculated he hijacked his own plane by locking his co-pilot out of the cockpit early in the flight after leaving Kuala Lumpur.
He then turned off the tracking gear and depressurised the aircraft – killing the others on board through hypoxia – a condition where the brain does not get enough oxygen.
The theories say Zaharie then steered in a U-turn while he puts on his pilot’s oxygen mask with hours of supply, and sets a course for the southern Indian Ocean.
He ended his act of mass murder-suicide by ditching the plane in the sea to minimise damage and wreckage spill.
Others have speculated Zaharie may have made it out alive from the doomed aircraft by parachuting from the aircraft and rendezvoused with accomplices.
Malaysian investigators previously drew no conclusion about what happened aboard the flight, but did not rule out the possibility that the aircraft had been deliberately taken off course.
– With CNN
This story first appeared on Radio Today