British pilot and aviation commentator, David Learmount has stated in an interview for a British Channel 5 documentary that only a person with training and insight into the specifics of flying a Boeing 777 could have controlled the MH370 flight, taking it off route.
"It was a highly qualified human being, well-trained in the workings of the 777 who did this", Learmount.
While Learmount didn't elaborate, whether he suspects one of the pilots, earlier hypotheses from several aviation experts suggested that Zaharie Ahmad Shah, the chief pilot on the doomed flight, could have tricked the co-pilot into leaving the cabin, locked himself up in it, and diverted the plane into the India Ocean, where it crashed running off fuel. Some experts suggested he could have committed suicide this way.
This theory was supported by various reports of Shah having mental health issues, namely depression, in the light of family problems over his alleged love affairs. Another media report said that investigators found out that Shah had flown the flight course like the one MH370 took on a flight simulator days before the plane went missing. The flight simulation ended with the plane crashing into the Indian Ocean.
Numerous theories by former pilots and other experts suggested radically different versions, from the plane being hijacked by terrorists and hidden in a remote airfield, to the jet's controls being hacked from the ground.
The abundance of speculations, sometimes bordering on conspiracy theories, stem from the plane's fate remaining unknown to this day. Search, and rescue missions yielded no results, and the few pieces of debris were found on the shores of the Indian Ocean, giving little clues as to where the plane had crashed.
Malaysia Airlines Flight MH370 vanished from radars on 8 March 2014 between Malaysian and Vietnamese airspace, while flying to Beijing. After several years of fruitless attempts to find the plane's crash site, the Malaysian government ended its search in May 2018. Official investigators admitted not knowing what caused the plane's disappearance.