Pilot’s Abrupt Maneuver in Low Approach Causes Fatal Terrain Impact, Investigation Reveals

…𝒓𝒆𝒑𝒐𝒓𝒕 𝒉𝒊𝒈𝒉𝒍𝒊𝒈𝒉𝒕𝒔 𝒑𝒊𝒍𝒐𝒕 𝒇𝒂𝒕𝒊𝒈𝒖𝒆 𝒂𝒏𝒅 𝒐𝒓𝒈𝒂𝒏𝒊𝒛𝒂𝒕𝒊𝒐𝒏𝒂𝒍 𝒐𝒗𝒆𝒓𝒔𝒊𝒈𝒉𝒕 𝒂𝒔 𝒄𝒐𝒏𝒕𝒓𝒊𝒃𝒖𝒕𝒊𝒏𝒈 𝒇𝒂𝒄𝒕𝒐𝒓𝒔 𝒊𝒏 𝒕𝒓𝒂𝒈𝒊𝒄 𝒊𝒏𝒄𝒊𝒅𝒆𝒏𝒕

Sonam Deki

The final accident investigation report on the EC130 T2/H130 (MSN:8160) helicopter, registered as A5-BHT and operated by Drukair Helicopter Services, has been released by the Air Accident Investigation Unit of the Ministry of Infrastructure and Transport. The incident, which occurred at Wachey-Lunana in Gasa, Bhutan, has been attributed to terrain impact resulting from the pilot’s abrupt change in flight maneuver during a low approach, leading to a potential loss of obstacle clearance.

On March 3, 2023, the A5-BHT helicopter of Drukair Helicopter Services was operating local chartered commercial flights between Khuruthang (Punakha) and Lunana (Gasa). The first trip on March 3, 2023, was operated between Khuruthang and Thango and thereafter, four trips to Wachey. Departing from Paro helipad at approximately 09:30 local time (03:30 Coordinated Universal Time-UTC), the helicopter landed at Khuruthang around 09:47 local time (03:47 UTC). Subsequently, at about 10:17 local time (04:17 UTC), it took off from Khuruthang for its first trip to Thango. The accident occurred during its fourth flight towards Wachey from Khuruthang with the pilot and four passengers onboard. During its final flight, the helicopter took off from Khuruthang at 14:08 LT (08:08 UTC) and had a flight duration of 16 minutes 35 seconds before it crashed at 14:25 LT (08:25 UTC) about 200 meters northeast of the intended landing site. The flight adhered to the Visual Flight Rules (VFR) under Visual Meteorological Conditions (VMC).

The investigation identified several contributing factors to the accident. It was noted that the company failed to adhere to the pilot roster on the day of the accident, as another senior pilot was on active duty but the involved pilot operated the flights. The report highlighted that the pilot involved had been on active duty for six consecutive days, including the day of the accident. Emotional distress was also a significant factor, with the pilot experiencing issues due to the bad attitude and reluctance of a senior pilot to listen to his concerns. The report points out that the pilot was acting as an officiating supervisor in the absence of the regular supervisor. Furthermore, the pilot’s lack of assertiveness in reporting workplace issues to the supervisor and management contributed to the incident. The investigation also found that there was inadequate supervision of working relationships among pilots and the overall working environment by the supervisor and management. The history of the pilot performing aggressive maneuvers at low approaches was also noted.

In response to these findings, the report issued several safety recommendations. First, Drukair Helicopter Services is encouraged to ensure pilots and crews adhere to the roster and avoid unnecessary changes to flight duty without valid reasons. Second, the organization should encourage voluntary reporting of any safety issues related to the organization and working environment. Third, the service should strictly monitor passenger and baggage weights before each departure, adhering to weight limits, with the BCAA taking necessary action in cases of non-compliance. Fourth, awareness should be raised among ground staff and pilots about the importance of mitigating unhealthy practices related to unweighed and unmanifested extra passenger weights. Fifth, in line with the Operations Manual Chapter 9.4, Drukair Helicopter Services should ensure that pilots and ground staff use the correct payload onboard to develop the weight and balance manifest. Lastly, the service should assess and comment on pilots’ overall flying style during the 6-monthly Operators Proficiency Check (OPC) and take preemptive action against unconventional and unsafe maneuvering by pilots at any time.