With so many reports, unconfirmed reports, and conflicting reports, it may be difficult to follow what exactly is known about the disappearance of Malaysia Airlines flight MH370.
In the simplest terms, the flight disappeared from radar last Saturday. And, a week later, there are still no signs of its whereabouts.
The flight departed 12:21 a.m local time from Kuala Lumpur International Airport, due to land in Beijing at 6:30 a.m. On board the Boeing 777-200ER were 227 passengers and 12 crew members.
Listed among the passengers are the names of two men from Austria and Italy who are actually not on board. Those men say their passports were stolen. It was later learned that the two men with stolen passport were Iranians, aged 18 and 29, who had entered Malaysia using their real passports.
Malaysian police chief Khalid Abu Bakar said the younger man appeared to be an illegal immigrant and that his mother was waiting for him in Frankfurt. (Police do not think the pair are tied to any terrorist group.)
According to the flight tracking website flightaware.com, the plane flew northeast over Malaysia after takeoff and climbed to an altitude of 35,000 feet. The flight vanished from the website's tracking records a minute later.
Malaysia's defence minister said the engine manufacturers said the last engine data was received at 1:07 a.m. local time, around 15 minutes before the plane lost contact.
As the plane reached the boundary between Malaysian and Vietnamese airspace, the Malaysian air traffic control announced it was handing over to Ho Chi Minh City Control.
The cockpit replied, "All right, good night." That was the last known radio transmission from the plane.
About three minutes later, Vietnam's control centre noticed the airplane had disappeared from the radar.
This means the last sighting of the aircraft on civilian radar screens came shortly before 1:30 a.m. on Saturday, less than an hour after take-off.
Although the plane's last confirmed sighting on radar was around 1:30 am, Malaysia's air force chief has said that an aircraft that could have been the missing plane was plotted on military radar at 2:15 a.m., 320 kilometres northwest of Penang Island off Malaysia's west coast.
On Thursday, two sources close to the investigation told Reuters that satellites had picked up faint electronic pulses from the aircraft after it went missing, but added the signals gave no immediate information about where the jet was heading and little else about its fate.
Meanwhile, Reuters reported that its sources said an unidentified aircraft that investigators suspect was missing Flight MH370 appeared to be following a commonly used navigational route.
That course — headed into the Andaman Sea and toward the Bay of Bengal in the Indian Ocean — could only have been set deliberately, either by flying the Boeing 777-200ER jet manually or by programming the auto-pilot.
As well, a March 13 media report quoted U.S. investigators as saying they suspected the plane remained in the air for about four hours after its last confirmed contact, citing data from the plane's engines.
HUMAN INTERVENTION: A U.S. official said in Washington that investigators are examining the possibility of "human intervention" and that the disappearance may have been "an act of piracy." The key evidence behind the theory is the fact that contact with the Boeing 777's transponder stopped several minutes before a messaging system on the jet stopped working. Some experts are leaning toward the theory that pilots or someone else with aviation experience deliberately veered the plane off course. They find it hard to believe that a modern jetliner like the 777 would experience a total electronic failure that left the plane unable to communicate, yet able to keep flying.
TERRORISM: Early speculation leaned toward terrorism after two men, later identified as Iranians, boarded the plane with stolen passports. Authorities later determined they were migrants seeking to travel to Europe illegally. No group has claimed responsibility for the lost plane, and experts have questioned why, if the jet was hijacked, those responsible didn't target a city or military installation.
MECHANICAL FAILURE: Experts now see this theory as unlikely following word that the plane was emitting signals for hours after it disappeared, and given the fact that no debris has been recovered from close to the plane's last known position. The plane's flight data recorder and cockpit voice recorder can transmit signals for up to 30 days, but none have been detected.
DECOMPRESSION: Experts say it's possible the plane continued to fly while a decompression left everyone on board unconscious and unable to respond, similar to what happened in the 1999 crash that killed golfer Payne Stewart and five others. A Malaysian investigator said on Friday that based on the plane's course, it appeared a skilled person was flying in the cockpit.