What happened
On 15 February, a scheduled domestic service traveling from Jakarta toward Manado via Surabaya and Makassar experienced several technical and weather-related challenges. During the initial leg of the journey, the crew noted that the number four engine failed to synchronize while en route to Surabaya. Upon landing in Surabaya, technicians identified an oil leak on the number one propeller. After repairs were performed, the flight departed Surabaya but encountered severe weather when approaching Makassar. Following two unsuccessful landing attempts due to the conditions, the pilot elected to divert back to Surabaya-Juanda for an overnight stay.
The following morning, the aircraft departed Surabaya and landed in Makassar without further incident. The final leg of the journey toward Manado began with a planned arrival time of 0512 hours GMT. As the Lockheed L-188 Electra approached Manado, weather reports indicated a cloud base of 900 feet and visibility of 2 km. While flying at 1,500 feet, the pilot performed a 360-degree turn over the bay before descending to 900 feet to begin an approach to runway 18.
During the descent, the aircraft passed between two hills while the crew prepared for landing by lowering the undercarriage. The pilot noted that the aircraft was positioned left of the centerline and was too high on the approach. In an attempt to correct the glide path, the nose was lowered, but as the airspeed dropped below 125 knots, the aircraft maintained a right bank. The Lockheed L-188 Electra struck the ground approximately 156 feet short of the runway threshold. The impact caused the undercarriage to collapse, leading the aircraft to skid and catch fire. The accident resulted in 22 fatalities.
Findings
Investigation into the crash identified that an improper approach technique led to an excessive sink rate during touchdown. Several contributing factors were noted, including the narrow appearance of the 98-foot runway and uneven pavement which complicates landing precision. Additionally, marginal weather conditions necessitated a tight landing circuit. The investigation also highlighted a lack of understanding regarding the relationship between the aircraft's rate of sink and negative thrust at low speeds.