Mystery
shrouds the fate of Malaysia Airlines flight MH370, which has disappeared with
239 passengers and crew en route to Beijing.
There have been reports that debris was found off the Vietnamese
island of Tho Chu but these have not been confirmed.
Who was on board?
There
were 227 passengers, including 153 Chinese and 38 Malaysians, according to the manifest. Two were children. All 12
crew members were Malaysian.
Among
the Chinese nationals were a delegation of 19 artists who had attended an
exhibition in Kuala Lumpur.
Two
male passengers were travelling on passports stolen from an Austrian and an
Italian in Thailand in 2012 and 2013 respectively, Interpol said in a statement. The two
passengers were en route to Europe via Beijing.
When was the last contact made?
Flight MH370 departed from Kuala Lumpur International Airport at 00:41
on Saturday (16:41 GMT Friday), and was due to arrive in Beijing at 06:30. Air
traffic controllers lost contact at 01:30.
At a time as yet undisclosed, a relative reportedly managed to call one
of the passengers, who was carrying a Singapore phone. Malaysia Airlines has
repeatedly tried to call the same number but no ringtone has been heard.
Where did the jet disappear?
It was flying over the South China Sea, south of Vietnam's Ca Mau
peninsula. The normal route would have taken it over Cambodia and Vietnam
before entering Chinese airspace.
No distress signal or message was sent but it is believed the plane
attempted to turn back from its scheduled path, perhaps towards Kuala Lumpur
Airport.
Have any traces of the plane been found?
Both
waters to the east of Malaysia, in the South China Sea, and in the Straits of
Malacca, along Malaysia's west coast, are being searched.
No wreckage has been confirmed despite an earlier indication
that potential debris from an aircraft had been seen about 50 miles [80km] to
the south-west of Tho Chu Island.
Azharuddin
Abdul Rahman, head of Malaysia's Department of Civil Aviation, said on Monday:
"Unfortunately, ladies and gentleman, we have not found anything that
appears to be objects from the aircraft, let alone the aircraft itself."
What are the theories for
a crash?
Common
factors in plane crashes are poor weather, pilot error and airworthiness. Weather conditions on this flight are said to have been good and
the pilot, 53, who had more than 18,000 flying hours behind him, had been
employed by the airline since 1981.
Malaysia
Airlines has a good safety record and the jet, a Boeing 777-200ER, is said to
be one of the safest because of its modern technology. One of the plane's
wingtips was clipped in an incident while taxiing in 2012 but it was repaired
and certified as safe.
David
Learmount, Flight Global's operations and safety editor, told BBC News:
"Today's aeroplanes are incredibly reliable and you do not get some sudden
structural failure in flight. It just doesn't happen. It just won't
happen."
Could it have been a
terrorist attack?
The
airline says it is not ruling out any theory while officials in the US, which
is sending FBI investigators, say there is no evidence of such an attack yet.
The
presence of two passengers with stolen passports is a breach of security, but
could relate to illegal migration. "Quite a few people that do fly,
especially in that part of the world, with improper identification or false
identification," former head of the US air security agency John Magaw told
the BBC.
Claims
have emerged from Malaysia that the two men were in fact Iranians who were
heading to Europe to seek asylum.
When an
Air India plane crashed in Mangalore in 2010 en route from Dubai, with the loss
of 158 lives, as many as 10 fraudulent passports were recovered.
Can a modern jet just vanish without trace?
An Air
France jet flying from Brazil to France vanished into the Atlantic Ocean on 1
June 2009, with the loss of all 228 people on board.
Flight
recorders, or "black boxes" as they are often known, emit ultrasonic
signals that can be detected under water. Under good conditions, the signals
can be detected from several hundred miles away.