"We can conclude that MH370 had turned back, and the turn back was not because of anomalies in the mechanical system. The turn back was made not under autopilot but under manual control. Everyone participating in the investigation agreed that the autopilot was off at the time of the turn," investigator in charge of the Malaysian Safety Investigation Team for MH370, Kok Soo Chon, said Monday during a press conference in Putrajaya, Malaysia.
According to the report, the plane's turn toward the Indian Ocean was not caused by the technical condition of the aircraft or the malfunctioning of onboard systems, and thus external interference in piloting the aircraft cannot be ruled out.
The investigation team found several violations of the safety protocols, including a 20-minute delay in the first attempt to establish communication with the plane by the flight operation officers of Ho Chi Minh City airport, Kok added.
However, according to the official, concrete conclusions about MH370's disappearance cannot be made until the majority of the plane's wreckage is found.
On Tuesday, Malaysian Civil Aviation chief Azharuddin Abdul Rahman accepted the report's findings that air traffic control did not follow standard procedures.
"It is with regret and after much thought and contemplation that I have decided to resign as the chairman of Civil Aviation Authority of Malaysia effective 14 days from the date of the resignation notice which I have served today," Rahman said in a statement, the Bangkok Post reported Tuesday.
The Boeing 777 airliner vanished en route from Kuala Lumpur to Beijing in March 2014 with 239 people aboard.
So far, the only evidence of the airliner is debris collected from Indian Ocean islands and on the east coast of Africa, with at least three pieces confirmed as parts from the missing plane.