What happened
On 16 March 2012, a Eurocopter AS350B3 helicopter, registration PK-ODA, was performing an unscheduled charter flight for the Freeport Indonesia Company in Papua, Indonesia. The aircraft, operated by PT. Airfast Indonesia, was conducting a series of shuttle flights between various helipads, including Timika, Utikinagon, and Wanagon, while transporting passengers and food supplies.
During the mission, the pilot attempted to land at West Gully but was forced to abort due to deteriorating visibility. As the flight continued toward MP 66, the weather worsened significantly, preventing a landing at the intended destination. The pilot subsequently decided to divert to Landville (MP 73), a location at a lower elevation that typically offers better ground visibility. The pilot's last radio communication occurred at 23:10, stating the intention to divert. Shortly after, an emergency locator transmitter (ELT) signal was detected by search and rescue authorities.
Following a search operation, the wreckage was located the next day at an elevation of 8,000 feet. The impact was severe, and all occupants were fatally injured.
The investigation
The investigation conducted by the NTSC focused on the wreckage, engine components, and flight history. Examination of the aircraft's main structure and blades indicated that the helicopter was in level flight with significant forward speed at the moment of impact. Technical analysis of the engine revealed that the engine was operating and delivering power at the time of the crash, as evidenced by misalignment marks on the drive gear shaft caused by a sudden increase in resistance when the rotor hit trees and the ground.
Investigators found no evidence of mechanical failure, system malfunctions, or pre-impact engine issues. The aircraft was confirmed to be airworthy, and the pilot was properly licensed and qualified for the operation. The investigation also noted that the aircraft was within approved weight and balance limits.
Findings
- The primary cause of the accident was a controlled flight into terrain (CFIT).
- Rapidly changing weather conditions led to extremely low visibility during the flight.
- The aircraft struck trees and the ground while in level flight at a high longitudinal speed.
- There were no mechanical or system failures contributing to the crash.
Safety action
Following the findings, the NTSC issued recommendations to the Directorate General of Civil Aviation and PT. Airfast Indonesia. These recommendations urge a review of training and checking requirements for pilots operating in remote, mountainous regions like Papua. Specifically, the focus should be on training for visual flight operations in unpredictable weather where advanced aids like TAWS, GPS, or radio altimeters may be unavailable or ineffective.