"Found Damaged Parts"... Two Black Boxes from Crashed Passenger Plane Fully Recovered

Whether Data Download Is Possible Is Key
Decoding Plan by Analysis Office of Gimpo Airport Aero-Rail Accident Investigation Committee

Firefighters are searching for fuel items at the site of the Jeju Air passenger plane collision and explosion accident that occurred 30 days ago at Muan International Airport in Jeonnam. Photo by Kang Jin-hyeong

Two black boxes, the key to determining the cause of the Jeju Air passenger plane disaster that occurred at 9:03 a.m. on the 29th, have been fully recovered. The black boxes of the accident aircraft consist of two devices: the Cockpit Voice Recorder (CVR) and the Flight Data Recorder (FDR). Immediately after the accident, the CVR was found intact 100%, but the FDR was recovered with some external damage. Overnight, the detached FDR was also found, securing the external parts of both black boxes from the accident aircraft. However, the extent of damage to the black boxes is severe, and whether data can be properly downloaded is crucial.

On the morning of the 30th, Gwak Young-pil, a section chief of the Central Accident Response Headquarters, said, "We have secured all the black boxes that were lost overnight and plan to move them to the Gimpo factory," adding, "The most important thing going forward is to decode the black boxes at the Aviation and Railway Accident Investigation Board’s analysis room at Gimpo Airport, but first, we need to check whether data download is possible."

The investigation into the cause of the accident requires analyzing and comparing the records of both devices. The decoding work of the FDR and CVR determines the overall direction and duration of the investigation. If both devices are intact and data can be downloaded, the decoding process is known to be possible within a week.

Firefighters are searching for fuel items at the site of the Jeju Air passenger plane collision and explosion accident that occurred 30 days ago at Muan International Airport in Jeonnam. Photo by Kang Jin-hyeong

The FDR records and preserves the aircraft’s flight path and the operational status of each unit in digital, magnetic, and numerical signals. It records the last 25 hours of flight data. The CVR records conversations between crew members inside the cockpit, communications between air traffic control and the crew, and various warning sounds within the cockpit. It records the last two hours until the engine stops.

Although both black boxes have been found, if data download proves difficult due to damage, the investigation may need to be entrusted to the U.S. National Transportation Safety Board (NTSB). In such a case, the decoding process could take several months.

The FDR and CVR are mostly installed in the tail section of the aircraft. In this accident, although the passenger plane’s body was burned to the point where its shape was unrecognizable, the tail section retained some form. Both devices can withstand temperatures up to 1100℃ for more than an hour and impacts up to 3400G (gravitational acceleration). In the past, they were called black boxes because of their black exterior, but currently, they are orange-colored boxes.