Unknown Or Undetermined, Eastindo Service (Airbus Helicopter MBB BK-117 D3 PK-RGH) About 35 NM North West of Gusti Sjamsir Alam Airport (Waok) KNKT.25.09.03.04

On 1 September 2025, a helicopter registered PK-RGH operated by PT. Eastindo Services was scheduled to conduct an unscheduled passenger flight from Gusti Sjamsir Alam Airport (WAOK), Kotabaru, to Tjilik Riwut Airport (WAGG), Palangka Raya, under Visual Flight Rules (VFR). On board were one pilot, one engineer, and six passengers.

Prior to departure, the engine fire bottle indicator illuminated in the cockpit. The pilot shut down the engine, and all occupants disembarked. Following inspection by the engineer, no evidence of fire or extinguisher discharge was found. The electrical connector of the fire detection system was cleaned, and after an engine restart, the warning light extinguished.

The helicopter then departed at 0045 UTC (0845 LT) for Palangka Raya. The pilot reported to Sjamsir AFIS that the estimated time of arrival was 1010 LT. The ACO instructed the pilot to report “10 minutes out.” At 0854 LT, the pilot reported accordingly, and was advised to establish contact with Banjarmasin APP. At 0858 LT, the pilot informed Sjamsir Alam Info that communication with Banjarmasin APP could not be established. The ACO then instructed the pilot to report when 30 NM from Kotabaru, which the pilot acknowledged. This was the last recorded communication from PK-RGH.

After losing contact, the ACO notified Banjarmasin APP, which then escalated the situation to BASARNAS. The uncertainty phase (INCERFA) was declared at 1109 LT and the distress phase (DETRESFA) at 1242 UTC. The SAR operation commenced at 1320 LT.

The last ADS-B data, recorded at 0903 LT, showed the helicopter at an altitude of 2,725 ft with a groundspeed of 118 knots on a heading of 295°, at coordinates 03°05′14.10″ S, 115°37′56.40″ E.

On 3 September 2025, the wreckage of PK-RGH was found on a ridgeline approximately 600 meters from the last ADS-B position, at an elevation of 2,200 ft, at coordinates 03°05′06.00″ S, 115°37′39.70″ E. The main fuselage was destroyed by post-impact fire, and the tail section was located separately uphill at coordinates 03°05′06.71″ S, 115°37′42.62″ E at an elevation of 2,400 ft. All eight occupants sustained fatal injuries.

The KNKT acknowledged the safety action taken by the aircraft operator was relevant in improving safety; however, in this preliminary investigation, there still remain safety issues that need to be considered. Therefore, the KNKT issues the following safety recommendations addressed to the aircraft operator and ATS provider.

The investigation is continuing. Should any further relevant safety issues emerge during the course of the investigation, KNKT will immediately bring the issues to the attention of the relevant parties and publish as required.