It’s the deadliest plane crash on South Korean soil, but unravelling the mystery behind the disaster has become much harder, after authorities revealed the black boxes failed to record the aircraft’s final four minutes.
The Jeju Air flight crashed at Muan International Airport on December 29, killing 179 people, after the pilot issued a mayday distress call.
The plane landed seemingly without its landing gear deployed and skidded along the runway, before smashing into a wall and exploding.
Authorities confirmed the plane suffered a bird strike, with the pilot issuing a distress call.
Just two minutes prior, air traffic control warned the aircraft about bird activity.
But soon after the distress call, both the aircraft’s black boxes stopped recording, meaning vital information from inside the cockpit is now lost.
"The analysis revealed that both the CVR and FDR data were not recorded during the four minutes leading up to the aircraft’s collision," South Korea’s transport ministry said on Saturday.
The ministry added it was not clear what caused the flight recorders to stop working, but stated other data was available to help with the investigation.
Pilot mentioned 'bird strike'
There are many questions about the disaster that have perplexed aviation experts.
Ordinarily, a bird strike is a manageable event, but the pilot made a hurried landing, with the aircraft landing in the opposite direction of the runway it was initially intended to land.
This meant there was not enough runway to allow the plane to stop.
The landing gears appeared not to have been deployed, with malfunction cited as a possible explanation.
Prior to the emergency landing, the pilot made a mayday distress call and used the terms "bird strike" and "go around".
But what happened next is unclear, with the final four minutes of cockpit recordings seemingly lost.
The passenger jet skidded along the tarmac before colliding with a wall and exploding.
Only two crew members at the very tail of the aircraft survived.
Black box failure linked to power cut
Black boxes can be damaged by impact or fire, but this didn’t clearly explain why only the final four minutes of recordings was lost.
Experts say a catastrophic power failure is one explanation for the black boxes failing to record.
"If the aircraft’s electrical system fails, the black boxes may lose power and stop recording," wrote Helwig Villamizer, editor of Airways Mag.
Sim Jai-dong, a former transport ministry accident investigator, told Reuters news agency the loss of recordings suggested all power, including backup, was cut, which was rare.
Investigators are also looking into the possibility both jet engines lost power because of the bird strike.
The crash prompted the South Korean government to order emergency inspections of all Boeing 737-800.
Photos of the black box show it was manufactured by the company Honeywell.
One of the black boxes was sent to the United States for processing after suffering damage in the crash.
The investigation into the crash is expected to take months.
The concrete wall at the end of the runway has attracted a lot of attention, with international airport runways meant to be clear of any such structures.
South Korean police have raided Jeju’s Seoul office and the operator of Muan International Airport as part of the investigation.
ABC/wires
