But which direction did it turn. If it flew to the north, that would take it over land towards Kazakhstan. Sources view this scenario ass highly unlikely.
But to the south is open water, no radar over the Indian Ocean with depths of up to 15,000 feet. And beyond that, Australia.
A source close to the investigation tells ABC News, that's where the search will be concentrated.
UNIDENTIFIED MALE: We're going to have to have some luck to find this aircraft. The search area is so gigantic.
KERLEY: And what then? Did the plane run out of fuel before crashing into the ocean, or more farfetched but still possible, did the plane land somewhere under the cover of darkness.
UNIDENTIFIED MALE: It's all consistent with somebody who wanted to simply vanish from the face of the Earth and make sure that the ultimate crash site was never found.
KERLEY: So while the search will have a higher profile here west of Australia in the southern Indian Ocean, all those moves to shut off cockpit communication systems, the major changes of direction, all those things are bringing a new scrutiny to the two pilots -- George.
STEPHANOPOULOS: OK. Thanks. And we want to get more on that criminal investigation right now from our senior justice correspondent Pierre Thomas. He's in Washington as well. Good morning, Pierre.
PIERRE THOMAS, ABC NEWS CORRESPONDENT: Good morning, George.
Finding everything there is to know about the pilots is clearly a top priority.
THOMAS: More than a week after the plane's disappearance, authorities search the homes of the captain and co-pilot of the now infamous Malaysia airlines flight.
UNIDENTIFIED MALE: I was shocked that they waited so many days to do it.
THOMAS: Malaysian authorities confirm they are still investigating all passengers. Sources tell ABC News these two men are one of the primary focuses of this early international investigation. The reason, authorities say the plane did a series of maneuvers, and there may have been an attempt to avoid radar.
So far, U.S. intelligence have found no evidence any of the other passengers or crew had any flight training or skill.
UNIDENTIFIED MALE: I'd look at the pilots first, obviously, they're in the cockpit. I'd get their information. But given the lack of information we have, then I'd start looking at who else is on the airplane.
THOMAS: There is an urgent effort to see whether the pilots had any ties to extremists or any personal, financial or psychological issues that could have made them commandeer the plane.
UNIDENTIFIED MALE: You do sort of an initial assessment of their life -- religion, athletics, social events, social clubs. In other words, how do they spend their time?
THOMAS: But there are still many questions. The captain is described as a family man who worked for charity, someone who would never hurt passengers. And authorities have to resolve whether one of the passengers could have forced one of the pilots to hijack the plane or had flight training they have yet to uncover.
Pilots have been accused of intentionally downing planes before. U.S. investigators concluded a co-pilot of an Egypt Air flight intentionally rammed the plane into the Atlantic Ocean in 1999. In 1997, a pilot from Singapore was accused of crashing his plane into a river.