3 The search for the missing Malaysia Airlines flight now spans two hemispheres. It includes deep oceans and eleven countries.... The search continues as new questions are raised about what happened during a crucial 15-minute time period ... as Flight 370, crossed into Vietnamese airspace. Investigators know the last transmission from the cockpit happened early in the flight. They don't know when the two communications systems were shut down... And THAT begs the question - did any of the crew or passengers aboard the flight, have anything to do with the plane's disappearance? 3 New data also suggests two possible routes: north across more than a dozen countries... Or south into the indian ocean. That's where more than 26 nations, including the U-S, continue scouring the vast open sea... Crews from jacksonville are now helping in the search. Channel 4's Hailey Winslow... Spoke with aviation experts about what may have happened to flight 370 ... and how locals are getting involved, Hailey. 3 3 The Aviation expert I spoke with wants to make it clear that flying is very safe...He says no major US airline has had an accident in almost 13 years...and we've never seen anything like this... 3 30-3553-1:00200 tons of metal - reflective to radar, painted bright white, which would show up on satellites...missing ... It appears to be an intentional act, but the MOTIVE remains a mystery... Aviation Expert Ed Booth believes the drastic change in altitude from 23,000 feet to 45,000 feet suggests whoever hijacked the plane, was trying to kill the passengers...bec ause the cockpit has an unlimited supply of oxygen...but the rest of the aircraft does not... If the aircraft is not on the bottom of the ocean, Booth says investigators should be able to find it...If it crashed on the water into hundreds of pieces, debris would float......Booth puts his would float... Booth thinks it's very unlikely the pilot was trying to commit suicide...He says a 53 year old captain at the pinnacle of his career , with 18-thousand hours under his belt would have to go through a medcial exam every 6 months since he was a teenager...So it's improbable that he would have a sudden mental break, want to commit suicide and take 290 people down with him. 3 Hailey, with so many countries and search teams involved, is there ANY progress being made in the physical search for this plane? ANSWER: One of the areas search teams are focusing on -- is The southern Indian Ocean -- it's reportedly the world's third- deepest ocean... and one of the most remote stretches of water, with little radar coverage.