`` All right , good night . '' Those are the last words heard from the cockpit of Malaysia Airlines Flight 370. Who said them ? Was it the captain or his first mate ? Or someone else in the cockpit with them ? Officials in Washington suspect it was either of the pilots -- and that one or both was involved in MH370 's disappearance on March 8 . And according to the Malaysian Prime Minister 's account of events , by the time those words were spoken , someone had likely already taken steps to alter the flight 's path -- intentionally . Malaysian investigators are not ruling out a hijacking by other actors . But they have searched the homes of the pilot and co-pilot . Information from international and Malaysian officials indicate that the Boeing 777-200ER passenger jet may have flown for hours after that last voice contact with the pilots . The duty of all pilots is to aviate , navigate and communicate , in that order , an aviation expert has told CNN . Someone may have kept aviating , but either they could n't -- or would n't -- communicate . This is what we know about the 53-year-old pilot captain and his 27-year-old first mate . Capt . Zaharie Ahmad Shah . Police had been outside his Malaysia home every day since the plane vanished , a source told CNN . But had not gone inside until recently . When they did , they probably found a flight simulator there . In a YouTube video he apparently posted , Zaharie can be seen sitting in front of one . And in a German online forum for simulator enthusiasts , X-Sim.de , there is a post from November 2012 in his name that says he built it himself . `` About a month ago I finish assembly of FSX and FS9 with 6 monitors . '' The message was signed Capt . Zaharie Ahmad Shah BOEING 777 MALAYSIA AIRLINES . FSX and FS9 are over-the-counter flight simulator games made by Microsoft . On Friday , the CEO of Malaysia Airlines said that everyone is allowed to pursue their hobbies . Zaharie , a pilot with 18,365 flight hours under his belt , is reportedly also a flight instructor . On the same YouTube channel , Zaharie gives workman 's tips on tinkering with a refrigerator and an air conditioner . CNN can not verify the authenticity of the social media posts . 1st Officer Fariq Ab Hamid . CNN 's aviation correspondent Richard Quest once visited MH370 's 1st Officer Fariq Ab Hamid in a Malaysia Airlines cockpit , when he was training . Quest watched him land the plane under supervision of a senior pilot in February . The captain described Fariq 's landing as textbook perfect . Fariq joined Malaysia Airlines in 2007 . He has 2,763 flying hours behind him and was transitioning to the Boeing 777-200 after finishing training in a flight simulator . As with Zaharie , not much is known to the public about Fariq . But Quest was not the only guest who had joined him in the cockpit . Passenger Jonti Roos got an invitation to check out the cockpit during a flight from Thailand to Malaysia -- one that Fariq was flying with another pilot . She took photos and said Farid and his colleague smoked in the cockpit . After MH 370 's disappearance , she reported her experience to journalists . Malaysia Airlines was aghast . `` We are shocked by these allegations , '' the airline said . Such a practice would be illegal on U.S. carriers after the September 11 , 2001 , terror attacks , but not necessarily so on international ones , Quest said . Exploring the possibilities . Does Roos ' story open up the possibility that a third or fourth person could have joined Zaharie and Fariq in the cockpit ? Like the exact whereabouts of Flight 370 , that 's yet unknown . But investigators believe that somebody must have done something . Not long after the flight took off from Kuala Lumpur communications systems were disabled , the plane 's transponder was turned off , Malaysian Prime Minister Najib Razak said Saturday . That last device is situated between the pilots and can be shut off with a twist of the wrist . For a pilot to turn it off would seem reckless because the information it transmits gives the plane vital protection . It helps people on the ground locate the plane . Someone would have to know how to do it and also know the plane would lose that protection . Then someone in the cockpit said good night . And the apparent lack of visibility on radar ? `` Airline pilots are not trained for radar avoidance , '' said aviation expert Keith Wolzinger , a former 777 pilot . They like to stay on the radar , because -- again -- it protects their plane . Only military pilots , he said , are usually keen on avoiding radar . The father of a passenger on the missing plane is hoping for an outcome that would sound shocking under normal circumstances . `` I hope the plane was hijacked , because then , at least , there is hope , '' Li from Hebei Province said . He did not give his full name . Li is waiting at a Beijing hotel with dozens of other passengers ' family members awaiting word on the fate of their loved ones . `` But if the worst happened then I will have no meaning in my life . This is my only son , '' Li said . As he walked away , he bent his head and cried . MAPS : What happened to Malaysia Airlines Flight 370 ?
By the time of last voice contact , something was likely already awry . U.S. officials indicated the jet may have flown for hours after last contact with the pilots . Pilot 's duties : Aviate , navigate , communicate ; communication cut off . Was a third person with them in the cockpit ? One pilot has let visitors in before .