What happened
On 29 April 2018, a Boeing 737-800, registration PK-LOO, operated by PT. Lion Mentari Airlines, was performing a scheduled passenger flight from Makassar to Gorontalo. During the instrument approach to runway 27, the flight crew received a warning from a preceding ATR aircraft pilot regarding heavy rain on the final approach area.
Upon touchdown at 1040 UTC, the aircraft encountered sudden, intense rainfall that severely restricted visibility, leaving the crew only able to see runway lights on the left side of the strip. As the pilot deployed the thrust reversers, the aircraft veered off the runway, coming to a stop on the left shoulder approximately 1,200 meters from the start of the runway. The impact caused the nose landing gear to collapse backward into the forward lower fuselage. Following the stop, the aircraft's communication and passenger address systems failed, necessitating a manual evacuation command to the flight attendants.
The investigation
The KNKT investigation focused on the environmental conditions and the operational response. Investigators found that the airport's Automatic Weather Observation System (AWOS) had been unserviceable for five days prior to the accident, meaning the tower controller had to rely on manual updates from meteorology observers.
During the evacuation, it was noted that while the forward cabin crew initiated the exit, the crew members in the center and aft cabins were unaware that the evacuation had begun. Additionally, the investigation revealed that the airport's crash bell was not connected to the new location of the Airport Rescue and Fire Fighting (ARFF) station, forcing the controller to notify emergency services via handheld radio.
Findings
- The nose landing gear collapse was the primary cause of the structural damage to the fuselage.
- The aircraft encountered heavy rain that significantly reduced visibility during the landing phase.
- The airport's automated weather monitoring system was non-functional at the time of the accident.
- There was a lack of coordination during the evacuation, as some cabin crew members did not realize the evacuation was in progress.
- The airport's emergency notification system (crash bell) was not integrated with the ARFF station's new location.
Safety action
Following the incident, the airline implemented corrective simulator training for pilots and flight attendants, specifically focusing on emergency procedures and situational awareness. The regulatory authority issued several safety recommendations, including the revision of operating manuals to explicitly prohibit landings during heavy rain or on contaminated runways, and the implementation of secondary communication methods, such as megaphones, for use when the passenger address system fails.