Ground Collision, Garuda Indonesia (Boeing 737-800 PK-GMP) Bandar Udara Internasional Kualanamu, Medan, KNKT.24.10.22.04

On 16 October 2024, a Boeing 737-800 aircraft registered PK-GMP was operated on a scheduled passenger flight from Soekarno-Hatta International Airport (WIII), Jakarta, to Kualanamu International Airport (WIMM), Medan. On board the aircraft were two pilots, five flight attendants, and 102 passengers.

At 1210 UTC (1910 LT), during nighttime, the aircraft departed Jakarta, and the flight was uneventful until landing at Kualanamu. At 2113 LT, the aircraft landed on Runway 23 and taxied to Parking Stand W29 via Taxiways G, A, A2, and U.

At 2126 LT, the aircraft was taxiing on Apron W and turned right to Parking Stand W29, following the lead-in line. At this time, the Flight Data Recorder (FDR) recorded that the aircraft's ground speed was approximately 5 knots, and engine N1 was about 21%.

At 2126 LT, the airport CCTV recorded that when the aircraft was in line with the parking stand, a Lavatory Service Truck (LST) which was parked in the Equipment Staging Area (ESA) began moving unaided. When the aircraft reached the parking position and stopped, the LST impacted the tail section of the aircraft. No persons were injured as a result of this occurrence; however, the aircraft and the LST were damaged.

The investigation did not find any record or report of any aircraft system malfunction and determined that the aircraft's serviceability was not an issue in this occurrence. Therefore, the analysis discusses the relevant issues of unintentional movement of the LST, awareness of the Ground Service Equipment (GSE) operator, and serviceability of the LST.

The KNKT concluded the contributing factors as follows:

• The assumption that an the unserviceable parking brake could be replaced with a wheel chock resulted in the LST with an unserviceable parking brake being assessed as a serviceable vehicle during periodic inspection and daily checks.
• The combination of late-evening work and developing fatigue might have influenced the improper placement of the wheel chock.
• The vibration from the LST engine running and the aircraft movement toward the parking stand, combined with the suction effect generated by the aircraft engine, might have triggered the movement of the LST.
• The existing triggering conditions to move the LST, combined with the downslope of the parking surface, the unserviceable parking brake, and improper placement of the wheel chock, resulted in the unintentional movement of the LST.

At the time of issuing this investigation report, the KNKT had been informed of the safety action taken by the ground handling service provider resulting from this occurrence and considered that the safety action was relevant to improving safety. However, there were still safety issues that needed to be considered, and the KNKT issued several safety recommendations to the ground handling service provider, airport operator, aircraft operator, and civil aviation authority.