The black boxes of a Boeing jet that crashed in South Korea last month stopped recording data about four minutes before the crash, South Korean officials said Saturday, a move that could complicate investigations into the causes of the crash that killed 179 people.
After analyzing the devices, the U.S. National Transportation Safety Board (NTSB) found that both the flight data recorders and cockpit voice recorders stopped working about four minutes before the crash, the South Korean Ministry of Transportation said.
A Boeing 737-800 operated by Jeju Air skidded off the runway in the South Korean city of Muan on December 29 after the landing gear failed to deploy, struck a concrete structure and burst into flames, killing all but two of the 181 people on board.
After an initial analysis of the black boxes, South Korean officials sent the devices to the NTSB for closer examination after discovering some data was missing. The transport ministry said it was not immediately clear why the devices did not record data in the last four minutes.
“Data from the CVR (cockpit voice recorder) and FDR (flight data recorder) is crucial to accident investigations, but such investigations are conducted by examining and analyzing various sources of information, and we plan to do everything we can to determine the cause accident,” the ministry said in a statement.
An investigation is underway to determine what happened after a Jeju Air Boeing 737-800 crashed off a runway in South Korea on Sunday. One of the main issues in the investigation is why the plane did not extend its landing gear during the emergency landing, according to former chief accident analyst Eugen Abramovici.
South Korean investigators said air traffic controllers warned the pilot of a possible bird strike two minutes before the plane issued a distress signal confirming a bird strike had occurred, after which the pilot attempted an emergency landing.
South Korean officials also pledged to improve airport security after experts linked the high death toll to the Muan airport locator system, the structure the plane hit when it crashed.
The locator, a set of antennas designed to guide aircraft during landings, was placed in a concrete structure covered with earth on a raised embankment. This raised questions about whether the structure should have been built with lighter materials that would break more easily on impact.
South Korea's acting president Choi Sang-mok has ordered emergency safety inspections of all Boeing 737-800 aircraft operated by the country's airliners following the Jeju Air crash that killed almost all passengers on board.