Nightly News | March 17, 2014
>>> is without a doubt the most baffling aviation mystery of our time and it seems like everyone by now has a theory, a guess or opinion about what happened to malaysia airlines flight 370. after ten days the best investigators have been able to determine that is the disappearance of the jet was a deliberate act. and that it flew off somewhere into the northern or southern hemisphere . but the question of who is behind it has tonight cast suspicion on the pilots. even as officials again today revised the timeline of this mystery. once again tonight tom costello leads off our expanded coverage. any signs of this search scaling back?
>> a little bit. the pentagon telling us it is preparing to reduce the u.s. part of the search. the " uss kidd " will soon end search operations leaving only p-8 and p-3 aircraft to search massive areas of water. and with no other country finding any sign this plane was ever on radar, the search zone is shifting to the south. just 500 feet above the indian ocean a u.s. anti-submarine hunter today searching for any sign of flight 370. also today, more contradictions from malaysian authorities. after first saying the plane's last automated data or acars transmission was turned off before the last cockpit radio call, suggesting pilot involvement, today authorities backtracked.
>> we don't know when the acars system was switched off. all we know is the last transmission. and we did not receive a next transmission.
>> reporter: here's the latest timeline. 12:41 a.m . saturday, march 8th , 370 left kuala lumpur bound for beijing. 1:07 a.m . it transmitted its last automatic data burst, called acars . the next acars transmission was scheduled for 30 minutes later. it never came. 1:19 a.m . the copilot radioed "all right, good night" as malaysian air traffic controllers handed the plane over to vietnamese controllers. just two minutes after the very standard conversation, 1:21 a.m ., someone in the cockpit turned off the transponders that send speed, location, altitude and heading information. soon after that the plane turned around. at 2:15 a.m ., the last radar contact in the strait of malaga, headed north. over the next six hours the plane transmitted one ping per hour to an orbiting satellite until 8:11 a.m . when the last ping was received. that puts it somewhere along these two arcs. as far north as kazakhstan. as far south as the deep indian ocean . australia is now taking over that search zone.
>> we will do our duty to the families of the 230 people on that aircraft who are still absolutely devastated.
>> reporter: experts say turning off acars and the transponders, then flying the 777 for hours, requires expertise which is why there's intense focus on the cockpit crew.
>> what is a potential motive, and what can be learned from looking deeply into the background of the pilot, the copilot, and anybody else on that plane that had the skill to fly it.
>> reporter: meanwhile, for the family of american philip wood, the wait is agony.
>> i don't believe that the plane has been crashed. i haven't ever believed the plane has been crashed. it just doesn't make sense to me. and i don't feel like that's the right answer.
>> reporter: investigators continue to look at the backgrounds of everyone on board, including an off-duty flight engineer. but his father tells nbc news he was not a pilot, he was only a mechanic. lester?