Newly revealed information suggests a missing Malaysia Airlines jetliner made a turn up the Strait of Malacca subsequent to a previously reported turn to the west that occurred around the time air traffic controllers lost contact with the plane, a senior U.S. government official who has been briefed on the investigation told ABC News.
The turns are indicative of someone at the controls of the plane, the official suggested -- an assessment that other experts seemed to agree with.
"That indicates that somebody may be on the controls," said Tom Haueter, a former director of the National Transportation Safety Board's Office of Aviation safety. "Slight turns I can see, but if somebody is making a major heading change, that would appear to be an intentional input to the controls."
Added Stephan Ganyard, an ABC News aviation consultant, "We are seeing what we call heading changes, where the aircraft changes its nose position and moves around the sky. This would confirm that we are seeing an airplane that's being controlled by pilots or somebody in that aircraft."
The search for the missing jetliner is focusing on two widely separated quadrants, one in the Malacca Straits off the west coast of Malaysia and the other hundreds of miles away in the northern Bay of Bengal, a U.S. official said today.
The focus on those areas is based on sharing of data by Malaysia and the U.S. that has led to determinations that there is a higher probability that the jetliner took a path in either of those directions, the official said.
The first official added that the searches in those quadrants will begin taking place over the next 24 hours.
Those quadrants were settled on today after a satellite communications company said that the missing plane contacted its network on the day it disappeared in what could turn out to be a big break in the effort to locate the jetliner or determine where it went. It was the latest indication that the plane flew far from its designated flight path that was intended to take its 239 passengers to Beijing.
"The satellite is saying it's a north arc and a south arc -- those would be the directions it would have gone in based upon the data, based on the pings," according to a second U.S. source.
The pings evidently came from technology inside Boeing aircraft that transmits a signal to a satellite that even pilots may not know about, ABC News has learned. This system establishes what is described as an electronic "handshake" between the airplane and the satellite.
However, this signal is crude when it comes to location data, so investigators will still be faced with a significant search. The pings occur every hour and ABC News has been told there were four or five of the transmissions. Searchers will use the last transmission to project out in their search.
Inmarsat, a British company, said today, "Routine, automated signals were registered on the Inmarsat network from Malaysia Airlines flight MH370 during its flight from Kuala Lumpur."
It said the information was shared with SITA, a company that specializes in air transport communications. SITA shared with details with Malaysia Airlines, Inmarsat said.
Inmarsat on its website said its satellite system "facilitates the automatic reporting of an aircraft's real-time position, including altitude, speed and heading, via satellite to air traffic control centres, helping controllers know where an aircraft is at all times."
If those "pings" sent by the Malaysia Airlines jet to the satellite indicate location or flying direction, it could help solve the mystery that began a week ago when the jet disappeared from radar.
ABC News had previously reported that the missing plane continued to "ping" a satellite after two of its communications system, including its transponder, had shut down.
Inmarsat's statement came hours after investigators said they could not rule out hijacking and are looking at whether one of the plane's pilots or crew could have been involved.
Malaysia's Transport Minister Hishammuddin Hussein made clear that investigators do not know what happened to the jetliner despite a week of intense searching.
U.S. officials who have been briefed on the investigation have said two of the plane's communications systems were shut down separately and it appeared to have been done manually.
"There are four or five possibilities which we are exploring," Hishammuddin told a news conference today. "It could have been done intentionally. It could be done under duress. It could have been done because of an explosion. That's why I don't want to go into the realm of speculation. We are looking at the all the possibilities."
When asked whether investigators were looking at whether one of the plane's two pilots or cabin crew could have involved in whatever happened to the plane, he replied. "We are looking at that possibility."