The Ministry of Transport is investigating the cause of the data loss after the worst plane crash in the country's history.
The black boxes with flight data and cockpit voice recorders of Jeju Air's Boeing 737-800 jetty they stopped recording about four minutes before the plane crash in South Korea in December, the country's transport ministry has said.
Jeju Air's Flight 7C2216 was flying from Thailand to Muan International Airport in South Korea on December 29, when it landed, it crashed into a concrete barrier and exploded, killing 179 of the 181 passengers and crew.
This was the worst plane crash ever on South Korean soil.
“The analysis showed that both CVR and FDR data were not recorded in the four minutes before the aircraft collided with the grounder,” South Korea's transport ministry said on Saturday, referring to the two recording devices.
The localiser is a barrier at the end of the runway that helps aircraft land and has been blamed for the severity of the accident.
The voice recording was first analyzed in South Korea, and, when data was found missing, it was sent to the laboratory of the National Transportation Safety Board of the United States, the ministry said.
But it appears that data was lost in the boxes containing information about the last moments of the flight, leaving authorities trying to find out what happened.
“Plans are in place to investigate the cause of the data loss during the ongoing accident investigation,” the ministry said.
Sim Jai-dong, a former transport ministry accident investigator, told Reuters news agency that he was surprised the missing data had been found and suggested that all power, the including backup, cut in flight, which is rare.
Investigators said the boxes were vital to their investigation but said they would not give up trying to find out why the accident happened.
Investigators have pointed to bird strike, faulty landing gear and runway obstruction as possible issues.
The pilot had also warned of a bird strike before pulling out of the first landing and taking off.
But instead of going all the way, the Boeing 737-800 jet we took a sharp turn and approached the airport's single runway from the opposite end, landing without landing gear.
This week, chief inspector Lee Seung-yeol told reporters that “feathers were found” in one of the recovered engines, but warned that a bird strike would not lead to immediate engine failure.
Authorities have raided offices at Muan airport where the accident happened, a regional aviation office in the southwest of the city, and a Jeju Air office in the capital, Seoul.
They are too Jeju's top official banned from leaving the country.
As the investigation continues, transport minister Park Sang-woo offered to resign earlier this week, saying he feels “a heavy sense of responsibility over this tragedy” .
