Investigation Summary
The flight was the second sector of the day for the crew, departing Sentani at 10:15 local time. Approximately 25 minutes into the flight, the crew contacted an Indonesian Air Force C-130 Hercules. The Hercules pilot warned Flight 9760D that the cloud base over Oksibil was low and suggested a detour via Kiriwok to avoid the weather. However, CVR recordings revealed that 15 minutes before impact, the Captain decided to fly 'direct Oksibil,' noting that the sky appeared blue ahead with a cloud layer at 10,000 feet. As the flight progressed, the weather conditions worsened. Two minutes before impact, the First Officer expressed concern about haze and visibility. Fifty seconds before impact, the Captain initiated a climb and a left turn to avoid terrain, but the aircraft was already deep within a mountainous gap. The aircraft was banking left and engines were at high power when it struck the mountain at 9,300 feet. The NTSC noted that Merpati Nusantara Airlines did not fully cooperate with the investigation, failing to provide complete details regarding the crew's training and line checks.
Final Conclusions
The National Transportation Safety Committee (NTSC) concluded that the accident was a Controlled Flight Into Terrain (CFIT). The primary cause was the pilots' failure to maintain visual flight procedures while flying below the lowest safe altitude. The crew attempted to continue the flight under VFR into instrument meteorological conditions (IMC) without sufficient terrain clearance, leading to an impact with a mountain slope during an evasive maneuver.
Photographic Evidence (1)
Video Analysis
The Crash of Merpati Nusantara Airlines Flight 9760D — A detailed look at the 2009 DHC-6 Twin Otter crash in Papua, Indonesia, exploring the challenges of VFR flight in mountainous terrain and the decisions leading to the CFIT accident.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
First Officer
Systems & Failure Modes
Cockpit Voice Recorder (CVR)
A Fairchild A100 recorder that captured the final 30 minutes of cockpit audio, revealing the crew's decision to bypass weather detours.
Visual Flight Rules (VFR)
The set of regulations under which the pilot operates an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going.
Interesting Facts
- 01The aircraft was not equipped with a Flight Data Recorder (FDR), which was not required by Indonesian regulations for this aircraft type.
- 02The Cockpit Voice Recorder (CVR) was recovered and provided critical data regarding the crew's decision-making process.
- 03The impact occurred at 9,300 feet, while the crew had discussed climbing to 10,000 feet to clear terrain.
- 04Technical records listed the airframe at 27,336 hours, though the NTSC final report noted it had accumulated over 30,000 flying hours in total.
Safety Actions & Advisories
NTSC Cooperation Recommendation
The investigation highlighted the need for operators to fully cooperate with the NTSC by providing complete crew training and line check records.