Flight History
On 3 February 2016, a Bell 206L-4 helicopter, registered PK-UAG, was operated by PT. Amur Aviation Indonesia on a charter flight. The planned route consisted of four sectors from Moses Kilangin International Airport (WAYY) in Timika to Enarotali Airstrip (WAYE), then to Bayabiru, Spot 99, and returning to Enarotali for overnight. The helicopter departed Timika at 0730 LT (2230 UTC) with one pilot and five passengers.
At 2317 UTC, the helicopter arrived at Enarotali. The pilot coordinated with the customer to conduct a survey flight to the Spot 99 helipad via Bayabiru. At 0015 UTC, the helicopter departed Enarotali with the same pilot and passengers, arriving at Bayabiru at 0030 UTC to disembark two passengers. At 0033 UTC, the helicopter departed Bayabiru for Spot 99. Weather between Enarotali and Spot 99 was clear.
At 0040 UTC, the helicopter arrived at the Spot 99 area at an altitude of approximately 150 feet. The approach was made on an inbound heading of 066 degrees, followed by a right turn for a final approach from the north of the helipad. At about 30 feet above ground level (AGL) and a speed of approximately 10 to 15 knots, the helicopter entered a spin to the right. The pilot pushed the cyclic stick to gain speed and applied left rudder pedal in an attempt to recover. The spin did not stop, and the pilot reduced the power lever to idle. The helicopter impacted the roof of a local house near the helipad at coordinates 3° 36' 2.60" S, 136° 18' 15.61" E.
Injuries and Damage
The pilot was seriously injured; three passengers were not injured. Two local houses were severely damaged. The helicopter sustained substantial damage from the impact forces.
Investigation
The Komite Nasional Keselamatan Transportasi (KNKT) investigated the accident. The helicopter was not equipped with a flight data recorder or cockpit voice recorder; thus, the investigation relied primarily on witness statements and Global Positioning System (GPS) data. The KNKT concluded that the helicopter experienced a loss of tail rotor effectiveness (LTE) at a height too low above terrain to allow a successful recovery.
Safety Recommendations
The KNKT issued safety recommendations to PT. Amur Aviation Indonesia. As of the report's publication, the operator had not informed the KNKT of any safety actions taken in response to the occurrence.