What happened
On 2 June 2015, a Boeing 737-800, registration PK-GFA, operated by PT. Garuda Indonesia, was performing a scheduled passenger flight from Jakarta to Makassar. During the descent, air traffic controllers changed the active runway from 03 to 13 due to heavy cloud formations and rain affecting the original approach path.
As the aircraft approached runway 13, the crew noted rain and wet pavement on the far end of the runway. While the pilot monitoring noted a 10-knot tailwind and 10-knot crosswind at 100 feet, the aircraft experienced a significant float during the landing flare. Flight data revealed that the aircraft floated for approximately 13 seconds after passing 20 feet, traveling roughly 1,075 meters before touchdown. This late touchdown occurred well past taxiway Charlie, deep into the runway.
Fearing the mountainous terrain at the takeoff end of runway 13, the flight crew did not initiate a go-around. The aircraft subsequently struggled to decelerate on the wet surface. The pilot attempted manual braking and a slight left turn to avoid the runway end, but the nose and left main landing gear eventually became stuck in the mud at the edge of the stopway. There were no injuries among the 145 passengers and 8 crew members.
The investigation
The KNKT examined flight data recorder (FDR) and cockpit voice recorder (CVR) data, alongside airport CCTV footage. The investigation focused on the aerodynamic behavior of the aircraft during the transition from a tailwind to a headwind. Investigators also reviewed the meteorological conditions, specifically the presence of a mature-stage cumulonimbus cloud near the airport, which was known to produce downdrafts.
Findings
- The aircraft was airworthy and the crew held valid licenses.
- A significant wind direction shift occurred during the final moments of the approach, transitioning from a 9-knot tailwind to a 2-knot headwind.
- This shift, caused by downdrafts from a nearby thunderstorm, resulted in the aircraft floating for 13 seconds, leading to a touchdown point that required more runway than was available.
- The flight crew elected not to perform a go-around due to concerns regarding the mountainous terrain at the runway's departure end.
- Air traffic controllers had observed heavy cloud formations but lacked specific training in identifying windshear or the specific stages of cumulonimbus development.
Safety action
Following the incident, the DGCA monitored updates to Garuda Indonesia's simulator training, which was revised to include windshear avoidance and recovery techniques. The KNKT also issued recommendations for Garuda Indonesia to enhance meteorological training regarding cumulonimbus effects and for AirNav Indonesia to provide controllers with specialized training in windshear recognition.