Those statements by senior Malaysian officials hardened suspicions of a hijacking and Malaysian police intensified their investigations into all 239 people on board and everyone who came into contact with the plane before it departed Kuala Lumpur, taking particular interest in the backgrounds of the pilots. However, the second review of the backgrounds of crew and passengers by Malaysian and Chinese investigators appears to have thrown up no new leads. "All right. Goodnight." Fariq Abdul Hamid, co-pilot of MH370, made the last contact with air traffic control at 1.19 am. So, when Malaysia Airlines chief executive Ahmad Jauhari Yahya contradicted the information about the timing of the system being disabled at a press briefing on Monday night, saying the final transmission by the co-pilot Fariq Abdul Hamid may have occurred before any of the plane’s communications systems were disabled, it again opened up the possibility of a mechanical failure or abrupt event. Mr Ahmad Jauhari said the ACARS system had worked normally at 1.07 am but then failed to send its next scheduled update at 1.37am. Mr Fariq spoke at 1.19am. Desmond Ross, an Australian commercial pilot and aviation security expert, said that while the focus has been on what Prime Minister Najib said appeared to be movements on board “consistent with deliberate action by someone on the plane” there are a number of possible explanations as to why the plane lost communication, turned back and flew on for more than seven hours.

He says one scenario is that the aircraft depressurised for some reason, possibly an explosion causing a hole in the fuselage. Did he try to turn the plane? Zaharie Ahmad Shah, pilot of Malaysia Airlines flight MH370, seen in a photo posted to his community Facebook pages. “The pilots quickly recognise the need to descend,” said Captain Ross, who conducted a security review of Kuala Lumpur’s international airport in 2005. “One of them starts to reprogram the flight management system and sets a low attitude and starts to reset the heading to turn back to Kuala Lumpur…however he passes out before completing the entries into the computer for the new heading,” Captain Ross says. “The aircraft climbs out of control due to the explosion on board and then stalls at somewhere between the cruising height and 45,000 feet,” he says. “It falls out of control to the height the pilot had set into the flight management system but does not complete the turn back to Kuala Lumpur because the pilot had only partly entered the numbers….it flies off on an unknown path.” Captain Ross stressed that he has no direct knowledge of the investigation into one of the world’s most baffling aviation mysteries but said the more details he sees about the turn back the more he believes the plane ended up not being guided by human hands.

“I have a strong feeling that the flight management system was keeping the plane stable and level but that the heading was knocked out and the aircraft was essentially flying on erratic headings,” he said. “The apparently large changes in altitude also lead me to think that it was essentially out of control at that point but that the flight management system managed, somehow, to bring it level and stable at some point.” Captain Ross said what many people do not know is that the aircraft has to operate within a very narrow airspeed band in the thin air of high altitude. Loading “Too fast and the plane will go into a supersonic stall, too slow and it will simply fall out of the sky,” he said.

“At these altitudes the airspeed band can be as narrow as 50 knots and has to be managed very carefully and normally by the automated systems. So, if it got up too high, stalled and fell back to the low altitude, it may have stabilised and flown erratically with without being brought properly under control.”