What happened
On 3 August 2011, a Bell 412 helicopter, registration PK-FUG, was operating a scheduled charter flight for PT Nusa Halmahera Mineral. The flight was traveling from Sam Ratulangi Airport in Manado to Gosowong. The aircraft departed Manado at 14:26 local time with a crew of two and eight passengers.
Shortly after takeoff, the aircraft proceeded via a direct track toward Gosowong, passing the north side of Mount Klabat. The last communication with Manado Air Traffic Control occurred at 06:29 UTC, where the pilot reported a position on the 105 radial from the MNO VOR. Following this, the aircraft disappeared from radar. Search and rescue teams later discovered the wreckage in the tropical rainforest of Dua Saudara National Park at an elevation of 2,283 feet. All 10 persons on board were fatally injured.
The investigation
The investigation focused on the wreckage, flight path, and meteorological conditions. Analysis of the impact site revealed clean cuts on treetops and the collapse of several large trees, which indicated the aircraft was traveling at high speed and that the engines were providing power at the moment of impact. Examination of the tail rotor shaft showed twisting, confirming that the rotors were rotating during the collision. The investigation established that the aircraft's engines and flight controls were functioning properly prior to the crash.
Investigators also reviewed the flight route and weather. While the Manado airport authority had published specific guidance for VFR routes within the controlled airspace, the pilot had chosen a direct track to shorten flight time, bypassing the published guidance. Furthermore, weather at the accident site was characterized by clouds and drizzle, which provided visibility below the legal requirements for Visual Flight Rules (VFR) operations.
Findings
- The aircraft was airworthy and all mechanical systems, including the engines and rotors, were operational at the time of impact.
- The pilot was operating the aircraft under VFR while the weather conditions were below VFR minima.
- The flight path deviated from published VFR guidance in favor of a direct route to reduce transit time.
- The crew held valid licenses and medical certificates.