Recommends pilots and crews to adhere to roster and refrain from unnecessary changes

Sherab Lhamo

Aggressive manoeuvres performed by the pilot at lower approach and excess luggage could have caused the A5-BHT helicopter to crash on March 3 at Wachey-Lunana, last year,  according to the final accident investigation report published recently.

The report states the pilot did not strictly follow the flight roster and presence of poor working relationship between the pilots and lack of proper supervision from the supervisor. The pilot was acting as an officiating supervisor, while the supervisor was on leave and the replacement was done without valid reason.

The report that came after 10 months, stated that  there were differences in the statement of the pilot and the survivor in their accounts of the final approach and moments before the impact. The report states that the probable cause could be terrain impact due to the pilot attempting an abrupt change of its flight manoeuvre in a low approach which has resulted in loss of obstacle clearance.

The report also states that the pilot had a history of performing aggressive manoeuvres at lower approach. The pilot also experienced emotional distress due to the bad attitude and reluctance of the senior pilot to listen to him, as the pilot involved in the accident was acting as an officiating supervisor.

The pilot involved in the accident was not assertive enough to report the issues of the working environment to the supervisor and the management, the report stated.

The pilot’s involved in the accident, did not adhere to the pilot roster where another senior pilot was designated for active duty on February 26, March 1 and March 3. The pilot involved in the accident flew continuously from February 26, 2023 to March 3, 2023. The pilot  had covered  six consecutive days before the accident, indicating lack of proper communication and coordination among the pilots and improper supervision by the head of division.

The report also stated that there was no proper supervision of the working relation among the pilots and the working environment by the supervisor and the management.

According to the report, the survivors and pilot gave different statements on the abrupt change of its flight manoeuvre, where the pilot said that during the final approach towards landing site after a successful turn, it encountered sudden and violent change in wind direction, resulting in loss of airspeed and lift. 

According to the survivor, the helicopter failed to recover from a sharp left turn and was still banking left when it lost lift, ultimately crashing among the trees. An eye witness verified, according to the report, stating the helicopter was banking left as it descended into the trees. During the time of the accident, the witness stated the weather was fine with no clouds and no strong winds. 

Meanwhile, the air accident investigation unit, ministry of infrastructure and transport, recommended Drukair helicopter Services to encourage the pilots and crews to adhere to roster and refrain from unnecessary change of flight duty without valid reasons, reporting safety issues concerning the organisation and working environment and strictly monitoring passenger and baggage weights prior to departure.

The unit also recommended creating awareness among ground staff or pilots on the importance of mitigating unhealthy practice of passenger loading of extra weights that are not weighed or manifested. “The Drukair Helicopter Service shall ensure that the pilot along with ground staff use correct payload onboard to develop the weight and balance manifest,” the report stated.