The flight recorder on the Jeju Air jetliner that crashed last month, killing 179 people, stopped recording for its final four minutes, South Korean officials said Saturday, a significant setback for the investigators.
Data extracted from the so-called black box, consisting of the cockpit voice recorder and the flight data recorder, is usually crucial in aviation accident investigations. South Korean officials, who worked with the U.S. National Transportation Safety Board, said flight data from the plane’s last four minutes would be particularly important in the crash.
But on Saturday, South Korea’s Ministry of Land, Infrastructure and Transport said that for reasons not yet determined, the Boeing 737-800’s black box then stopped recording.
“We plan to investigate why the data was not recorded,” the ministry said in a statement. He also said further data and analysis would be used to try to understand what happened in last month’s disaster.
Jeju Air Flight 7C2216, arriving from Bangkok with 181 people on board, was preparing to land at Muan International Airport in southwest South Korea at 8:59 a.m. on Dec. 29 when its pilot signaled, “Mayday, mayday, mayday.” and “Bird strike, bird strike,” according to officials. The pilot also told the air traffic control tower that he was “circling,” meaning he would abandon his first landing attempt and circle in the air to prepare for a second.
But he apparently didn’t have time to complete the loop. Instead, the plane approached the runway from the opposite direction and landed on its belly, without its landing gear deployed. Seeming unable to control his speed, he overshot the track. Four minutes after Mayday’s emergency report, the plane struck a concrete structure at the south end of the runway and exploded in flames.
A key question was: what happened in those four minutes?
“The black box data is crucial in the investigation,” said Hwang Ho-won, president of the Korea Aviation Safety Association. “If the investigators don’t have it, it will create a serious problem for them.”
The missing data adds mystery to the crash, which was the worst air disaster on South Korean soil and the world’s deadliest since that of Lion Air Flight 610 in 2018, when all 189 people on board died.
Mr Hwang said the black boxes could be damaged by impact, fire or prolonged exposure to deep water. But it is difficult to explain why Jeju Air’s black box failed to record in its last four minutes, he said.
He said investigators may be able to piece together some of the conversation inside the cockpit based on interviews with control tower officials. Radar and other data suggest the plane tried but failed to gain altitude after reporting a bird strike and rushed to land, Mr. Hwang said.
Investigators said they were looking at various possibilities, including that the plane lost use of one or both of its engines during its final minutes.
Most of the 179 people who died were South Koreans returning home from the Christmas holiday in Thailand. The two survivors were both crew members found injured at the tail of the plane.
The disaster sparked a national outpouring of grief, with memorials erected across South Korea, and came as the country also grappled with a political crisis triggered by the president’s short-lived imposition of martial law Yoon Suk Yeol and his impeachment by Parliament.
