What happened
On 3 February 2013, a Jeju Air B737-800, registration HL7780, experienced a runway excursion during its landing roll at Gimpo International Airport. The aircraft, operating a scheduled domestic flight from Jeju International Airport, touched down on runway 14R amidst heavy snow and low visibility.
During the landing roll, the aircraft failed to decelerate sufficiently to vacate the runway via taxiway B1. Instead, the plane continued straight, eventually veering into the green zone approximately 40 meters beyond the end of the paved runway. There were no injuries and no damage to the aircraft resulting from the incident.
The investigation
The ARAIB investigation examined the flight crew's actions, the aircraft's mechanical state, and the airport's snow removal operations. The investigation reviewed flight data, cockpit voice recordings, and meteorological reports.
Investigators found that while the aircraft's maintenance records showed no defects in the braking or deceleration systems, the runway surface was subject to recent snow removal. Although friction tests had been conducted, the last third of the runway—which had seen minimal traffic—was covered in more snow than the preceding sections. The investigation also noted that the flight crew had received multiple reports of poor braking action from other aircraft prior to their arrival, but did not adjust their landing strategy accordingly.
Findings
- The pilot flying (PF) disengaged the deceleration system prematurely, switching from auto brakes to manual brakes while the aircraft was still at a high speed.
- The flight crew failed to conduct a proper landing briefing, which resulted in a lack of shared information between the pilot flying and the pilot monitoring regarding landing distance and deceleration plans.
- The PF failed to respond to the increasingly slippery conditions in the final section of the runway, operating under the mistaken belief that there was sufficient remaining distance to stop.
- The crew did not adequately consider the specific runway surface conditions or the potential for increased slipperiness in the unused portion of the runway.
- The airport did not provide specific information regarding the increased snow accumulation in the final third of the runway following snow removal operations.
Safety action
To Jeju Air:
- Implement measures to prevent pilots from skipping landing briefings.
- Update flight procedures and training to ensure better coordination of deceleration plans during adverse weather.
- Enhance training regarding the interpretation of runway friction tests and the unpredictable nature of runway surfaces during continuous snowfall.
- Incorporate additional speed callouts into standard procedures to ensure safe deceleration.
To Korea Airport Corporation:
- Update airport operation regulations to include regular assessments of the runway surface condition, specifically for the sections of the runway that receive the least traffic, and ensure these results are communicated to the control tower.