that appear to be human driven. you have a transponder being turned off. you have an acars system being turned off. you have the plane being turned not once but at least twice probably three times. >> and most perplexing, no distress call. >> there are so many ways to notify people that there's a distress. uhf, vhf radio, many, many, many ways. >> none of that happened. >> none of that for seven hours. >> could it have been deliberate? to answer that question investigators zero in on the last two men known to be in control of the plane. seen here passing through security on the night of the flight. first officer fariq hamid was only 27 years old. >> very young to be flying a 777 in the u.s., but had gone