What happened
On 5 May 2016, a Eurocopter AS350 B3e with registration RP-C6828 was conducting a charter flight in Sarawak, Malaysia. After several intermediate stops, the aircraft departed Betong at 1612 LT, heading toward Kuching with five passengers and the pilot on board. Shortly after takeoff, the pilot transmitted an estimated position, but subsequent radio contact was lost.
During this period, other aircraft in the vicinity reported heavy rain and thunderstorms along the flight path. A search and rescue operation was initiated later that evening. Over the following days, the bodies of all six occupants were recovered from the Batang Lupar river, along with various aircraft components. The main wreckage of the helicopter was not located.
The investigation
AAIB Malaysia investigators examined the aircraft's maintenance history, the pilot's experience, and meteorological data. The investigation focused on the weather conditions near the accident site, which satellite imagery confirmed contained mature cumulonimbus clouds and moderate rainfall.
Investigators also reviewed the pilot's decision-making process and the response of the Kuching Air Traffic Control Centre. The analysis looked at the potential for spatial disorientation due to the low-altitude flight over water, the lack of visual references, and the impact of heavy rain on windscreen visibility.