South Korean authorities are grappling with unanswered questions after discovering that the black boxes on the Jeju Air Boeing 737-800, which crashed on December 29, stopped recording data just minutes before the disaster.
The crash at Muan International Airport claimed 179 lives, making it the worst aviation disaster on South Korean soil.
Black Box Failures and Ongoing Analysis
The transport ministry revealed that both the cockpit voice recorder (CVR) and flight data recorder (FDR) ceased recording about four minutes before the plane belly-landed, overshot the runway, and exploded into flames.
The recorders are critical for understanding the sequence of events leading to the crash.
Initial analyses in South Korea revealed the missing data, prompting authorities to send the damaged devices to the United States National Transportation Safety Board (NTSB) for further examination. Investigators are working to determine why the recorders failed, with experts suggesting a rare total power failure as a possible cause.
Possible Causes of Black Box Failures
Black boxes—comprising the CVR and the FDR—are engineered to endure extreme conditions, such as high-impact forces, intense heat, and prolonged submersion in water. Their failure in the Jeju Air crash is an extraordinary anomaly, leaving a critical gap in understanding the sequence of events leading to the disaster.
Below are potential explanations for the premature cessation of black box recordings, which are unlikely to be linked to the reported bird strike:
Total Power Failure
- Explanation: Black boxes rely on the aircraft’s power systems, with backup power designed to continue recording during emergencies. A complete failure of both main and backup power is exceptionally rare.
- Possible Causes: Severe electrical malfunctions, catastrophic damage to power systems, or accidental or deliberate severing of power connections.
- Likelihood: High —requires further investigation into the aircraft's electrical systems.
2. Software or Hardware Malfunction
- Explanation: A glitch or failure in the internal systems of the black boxes, such as data storage modules, or a short circuit or power surge in other aircraft systems, could lead to recording cessation.
- Implications: Raises significant concerns if systemic flaws are identified, particularly if the malfunction extends to black boxes in other Boeing 737-800 aircraft.
- Likelihood: Medium — This plausible scenario awaits further analysis of the devices’ internal components, currently under review.
3. Manufacturing Defect
- Explanation: Faulty components or substandard materials could result in premature failure of the black boxes. Such defects would raise concerns about the manufacturing and certification process.
- Implications: Could affect the reliability of black boxes in other aircraft of the same model.
- Likelihood: Medium—further analysis needed to determine if the failure was specific to this unit or systemic.
4. Physical Damage to Recorders
- Explanation: The black boxes could have been physically damaged due to structural failure or impact before the final moments of the crash.
- Key Consideration: Black boxes are located in the tail section, which remained intact in this incident. This scenario is unlikely given the aircraft’s condition upon initial impact.
- Likelihood: Low—physical damage is inconsistent with the crash’s dynamics.
5. Heat or Fire Damage
- Explanation: Black boxes may fail if exposed to extreme heat or fire, which can corrupt or destroy stored data.
- Key Consideration: The rear of the aircraft, where the black boxes are housed, did not burn in this crash.
- Likelihood: Low—fire damage does not align with observed conditions.
6. Sabotage or External Interference
- Explanation: Deliberate tampering or interference—either externally or by the crew—with the black boxes or related systems could have caused the devices to stop recording. In most modern aircraft, including the Boeing 737-800, black boxes are connected to the aircraft's electrical systems and are automatically activated during flight. There is no simple on/off switch for the crew to deactivate them.
However, the circuit breakers controlling the power supply to the recorders can be manually pulled, though this may not necessarily shut down the FDR which often has additional safeguards.
Attempting to disable black boxes during an emergency is highly unusual and unlikely. The only plausible reasons for a crew to try to deactivate black boxes could include:
- Deliberate Concealment: A rare and extreme scenario involving an attempt to hide information or actions.
- Accidental Disconnection: Mistakenly pulling circuit breakers while troubleshooting a power failure or other onboard issues.
- Misguided Troubleshooting: The possibility that the black boxes themselves were suspected of causing a short circuit or other power-related failure, leading to their disconnection.
- Key Consideration: While highly speculative, the possibility of sabotage cannot be entirely dismissed without further investigation. Generally, it would be difficult if not impossible to disable the FDR.
- Likelihood: Low—requires more supporting evidence.
Implications for Boeing
The failure of the black boxes is particularly concerning for Boeing, as these devices are integral to ensuring accountability and improving safety. If the root cause is linked to aircraft design or system architecture, it would reflect poorly on Boeing’s adherence to safety standards.
Boeing has faced scrutiny in recent years for safety-related issues, including those surrounding its 737 MAX series. Although the 737-800 is a different model with a strong safety record, the black box failure in this instance could raise broader concerns about the company’s manufacturing and quality assurance practices.
Sequence of Events
Jeju Air Flight 7C2216 departed from Bangkok, Thailand, bound for Muan in southwestern South Korea.
- Bird Strike Warning: Air traffic controllers warned the pilots about bird activity near the runway two minutes before the crash.
- Emergency Declared: The pilots declared a bird strike emergency and abandoned their initial landing attempt, initiating a go-around.
- Unusual Maneuver: Instead of performing a full go-around, the aircraft made a sharp turn and approached the runway from the opposite direction.
- Crash-Landing: The plane belly-landed without deploying its landing gear, struck a rigid embankment at the runway’s end, and exploded.
Footage of the crash and evidence from the site suggest significant structural damage before impact, exacerbated by the embankment’s design and placement.
Investigation Focus
Authorities are exploring several factors contributing to the crash, including:
- Landing Gear Failure: Investigators suspect a possible malfunction prevented the deployment of the landing gear.
- Rigid Embankment: The embankment supporting the localizer system is under scrutiny for its rigid construction and proximity to the runway, which may have intensified the crash’s severity.
- Bird Strike: Feathers found in one engine suggest a bird strike occurred, but experts caution that this alone rarely causes catastrophic engine failure.
Family Demands and Public Outcry
Victims’ families are calling for an independent investigation, expressing distrust in the transport ministry’s ability to lead a transparent probe. They are advocating for the inclusion of international experts to ensure impartiality.
The transport ministry has promised transparency and committed to sharing findings with the affected families.
Transport Minister Park Sang-woo offered his resignation earlier this week, citing a “heavy sense of responsibility” for the tragedy. Police have also raided Jeju Air’s offices in Seoul, the airport operator, and the local aviation authority to seize maintenance and operational documents.
The crash has sparked wider debates about aviation safety standards in South Korea, particularly regarding the design and maintenance of airport infrastructure. Aviation experts have highlighted the rigid embankment as a potential hazard, calling for an overhaul of safety protocols at regional airports.
As investigators work to piece together the final moments of Flight 7C2216, the missing black box data remains a significant hurdle.
The probe’s findings will likely take months, but families and the public are urging authorities to ensure accountability and prevent future tragedies.
