What happened
On 15 September 2020, an Airbus A330, registration PK-LEG, was performing a scheduled passenger flight from Jakarta to Medan. During the approach to Kualanamu International Airport, the flight crew encountered significant weather challenges, including the presence of large cumulonimbus clouds. After initially being assigned runway 05, the crew requested a change to runway 23 due to the visible thunderstorm activity.
As the aircraft descended, the autopilot disengaged at approximately 500 feet. During the landing roll, the aircraft drifted toward the left edge of the runway. While the pilot managed to realign the aircraft to the centerline using right rudder, the left main landing gear traveled off the runway surface near taxiway D before returning to the centerline near taxiway E. The aircraft eventually vacated the runway via taxiway G. There were no injuries among the 307 passengers and 11 crew members, though the incident resulted in damage to two runway lights and deep cuts to the aircraft's number 5 and 6 wheels.
The investigation
The KNKT investigation focused on the aircraft's flight path, the cockpit crew's actions, and the condition of the aerodrome. Investigators found that the left main wheel had accumulated grass, and inspection of the runway strip revealed that grass height had reached approximately 50 centimeters. This overgrowth was noted because the scheduled mowing for that sector was not due until late September.
Additionally, the investigation examined the flight crew's recent experience. It was noted that both the pilot in command and the second in command had significant gaps in recent flight experience, partly due to reduced operations during the COVID-19 pandemic and regulatory exemptions in place at the time.
Findings
- The aircraft drifted toward the left edge of the runway following the disengagement of the autopilot at 500 feet.
- High grass levels (50 cm) on the runway strip near the touchdown zone were present, which could contribute to water ponding and increased hydroplaning risks.
- The flight crew lacked recent operational experience on the aircraft type, with the second in command having not flown the type since February 2020.
- The airline lacked specific internal guidance on managing pilot proficiency during the period of regulatory exemptions issued during the pandemic.
Safety action
- The KNKT recommended that the Directorate General of Civil Aviation (DGCA) develop specific guidance for operators to manage pilot proficiency and recent experience during periods of regulatory alleviation.
- The KNKT recommended that the airport operator, PT. Angkasa Pura II, ensure more rigorous monitoring and maintenance of grass levels on the runway strip to prevent hazards related to runway slipperiness.