The investigation into the crash of a South Korea passenger jet is gathering pace as bereaved families prepare for funerals after authorities finished formally identifying the 179 victims of the country's worst air disaster.
The transport ministry said on Wednesday South Korean investigators had extracted data from the plane's cockpit voice recorder and would convert it into an audio file - critical information to try to explain the few minutes that led up to the crash.
The plane's flight data recorder - which is missing a key connector - would be sent to the US for analysis, the ministry said.
All 175 passengers and four of the six crew members were killed on Sunday when the Jeju Air jet belly-landed at Muan International Airport in the country's southwest and slammed into a sand and concrete embankment at the end of the runway, where it burst into flames.
Two crew members, located near the tail of the Boeing 737-800, survived the disaster.
The government declared a national mourning period until Saturday and the country scaled back new year's celebrations.
The transport ministry said two more US officials arrived late on Tuesday to join a team of about two dozen investigators including from the US National Transportation Safety Board (NTSB), Federal Aviation Administration, and aircraft maker Boeing.
"They're also planning to start a visual investigation into the wreckage," deputy minister for civil aviation Joo Jong-wan told reporters.
Officials have said investigators were expected to examine whether a bird strike, a failure of the landing gear to drop or problems with any other control systems played a role in the disaster.
They will also investigate the pilot's apparent rush to attempt a landing right after he had declared an emergency, officials have said.
Air safety experts have also questioned if the airport embankment designed to prop up navigation equipment was built too close to the end of the runway.
South Korea's acting President Choi Sang-mok on Wednesday called for a fair and objective investigation and said funeral procedures had begun after all the victims were formally identified.
"The most urgent matter at present is to return the victims to their families," Choi told an intra-agency meeting.
Airport authorities set up an altar late on Tuesday and on Wednesday buses carried relatives of victims to the crash site so they could pay their respects, just metres from the crashed plane's charred and broken tail - the only relatively intact part of the aircraft following the accident.
The Muan airport was brimming with mourners seeking to pay their tributes at the altar, leading to a queue of several hundred metres.
County officials sent an alert to urge visitors to go instead to a larger memorial set up in a sports complex about 9km from the crash site.
It could still take several days until all bereaved relatives can secure the release of the bodies of their loved ones.
