Korean investigators’ efforts to understand the Jeju Air Boeing 737-800 crash at Muan have suffered a setback after both flight recorders failed to capture the final 4min of the accident sequence.
The aircraft overran at high speed, striking the mounted localiser, while attempting a gear-up and apparently flapless landing on Muan’s runway 19 – having aborted its original approach to the opposite-direction runway 01.
Only two of the 181 occupants survived the 29 December accident.
Korea’s ministry of transport says that the cockpit-voice recorder had been retrieved in an “apparently intact” state but the flight-data recorder was found to have a damaged connector between the power supply and the data-storage unit.
While the cockpit-voice recorder information was extracted at Gimpo airport, the inquiry found that the storage “stopped” about 4min before the aircraft’s collision with the localiser.
“The cause is currently unknown,” says the ministry.
It sought assistance from the US National Transportation Safety Board to verify the information from the cockpit-voice recorder and to extract data from the flight-data recorder, a task which could not be conducted domestically.
The NTSB’s facilities in Washington obtained the data and analysed it over the course of 7-11 January in the presence of investigators.
But the ministry says that the analysis shows both the cockpit-voice and flight-data recorders “stopped storing” for the 4min period before the localiser impact.
“The cause of the data not being stored is planned to be identified during the accident investigation process,” it states.
While it stresses that flight recorders contain important information for investigations, inquiries analyse accidents by using various data sources.
“We plan to do our best to accurately determine the cause of the accident,” says the ministry.