Reporter: Good morning, robin. Yeah, you know, this did now the fourth date of this search. Up to now they've been searching in the seas, Malaysia to the north and to the east and now they expanded... See More
Reporter: Good morning, robin. Yeah, you know, this did now the fourth date of this search. Up to now they've been searching in the seas, Malaysia to the north and to the east and now they expanded that search and now looking in the sea to the west of Malaysia and they also -- the Vietnamese told us today they'll probably start searching on the ground in the mountains and the jungles of Vietnam. This morning, the frantic search for the missing Boeing 777 is expanding. Reports that the search now includes the thick jungles of Vietnam, focusing on densely populated areas, forests and mountains. The search will be based on the projected flight path right up the ho chi Minh, Malaysian authorities also say military radar suggests the flight may have tried to turn back and are now expanding the search to include the area just west of Malaysia, as well. But why would the plane turn around? The aircraft underwent maintenance 12 days before its takeoff that Saturday morning. The weather conditions were ideal and the plane was flying at 35,000 feet, the safest part of the flight. Most of the problems occur when airplanes are on takeoff or landing but up at altitude away from everything up well above the weather, the autopilot is on, the airplane -- the computer is flying the airplane, that is a really, really safe place to be. Reporter: If the crew and passengers were incapacitated and the plane was flying on autopilot, it could have ended up anywhere. So the search continues in the south China sea. 4 helicopters, 40 ship, even submarines, desperately looking for clues. The plane was tracked by radar as it soared out into the ocean, but that commercial radar only reaches about 250 miles into the sea. The plane does have black boxes, which can beep a series of pings although the waters are shallow, 165 feet deep, submarines and special ships need to be within five to ten miles to hear it. And now a Colorado satellite imaging company is launching a website asking the public to search, as well, watching high resolution images pixel by pixel. Three Americans were on board and another American businessman Greg Candelaria was scheduled to be on board. The only reason for this being skipped this one time, very unusual for me, is simply because I've had back-to-back long haul trips. It turned out to be the best decision in my life. Reporter: Now, the family members are really getting frustrated in bank. Some we saw getting on a bus and heading over to the airport to head down to Malaysia and want some kind of change. There have been so many plane crashes in this world but never has a plane budget lost for so long without any clues. Robin? Okay, bob, thank you.
This transcript has been automatically generated and may not be 100% accurate.