What happened
On a non-scheduled cargo mission from Wamena Airport to Kenyam Aerodrome, a Cessna 208B Grand Caravan crashed into terrain in the Yahukimani District of Indonesia. The flight was operating under visual flight rules, with the pilot initially notifying air traffic control of a planned altitude of 9,500 feet. The aircraft was transporting a manifest of groceries and diesel drums, along with an unmanifested load of 25 bags of rice weighing approximately 827 lb.
During the flight, the aircraft's airspeed began to decrease as it approached high terrain. Flight data indicates that the crew likely attempted to adjust their climb angle by decelerating toward the best angle of climb speed. Following this, the aircraft entered a descending right turn, followed by a left roll that reached a bank angle of 46 degrees. During this maneuver, the aircraft descended rapidly from 9,728 feet to 9,045 feet while airspeed increased. Despite the activation of three EGPWS alerts, the aircraft impacted the ground at an elevation of 9,100 feet, resulting in two fatalities.
Findings
Investigation of the accident revealed that the aircraft's takeoff weight was approximately 619 lb above the certified maximum takeoff weight due to the additional rice load. Furthermore, the aircraft's center of gravity was located outside of the certified envelope. These overloading conditions caused a reduced rate of climb, leaving the aircraft flying 1,500 feet lower than the altitude recommended in the operator's route guide for the area.