What happened
On January 15, 2023, an ATR 72-212A (registration 9N-ANC) was operating a scheduled shuttle flight from Tribhuvan International Airport to Pokhara International Airport. The aircraft was carrying 68 passengers and 4 crew members.
During the final approach to runway 12 at the new Pokhara International Airport, the aircraft experienced a sudden loss of control. The aircraft impacted the ground in the area between the old Pokhara Domestic airport and the new international facility, near the banks of the Seti River. The impact resulted in 72 fatalities, as all persons on board were killed.
The investigation
The investigation, conducted by the Aircraft Accident Investigation Commission of Nepal with international support from the BEA, NTSB, TSB, and TSIB, focused on the flight crew's actions and the operational environment of the new airport. Investigators examined the flight data recorder, cockpit voice recorder, and the physical wreckage, including the propeller assemblies and control pedestal. The inquiry also reviewed the airline's training programs, the regulator's certification of the new airport's visual approach procedures, and the crew's compliance with standard operating procedures (SOPs).
Findings
The investigation established that the inadvertent movement of both condition levers to the feathered position was the primary cause of the accident. This action caused both propellers to feather, leading to a significant loss of thrust, an aerodynamic stall, and the subsequent collision with terrain.
Several contributing factors were identified:
- High pilot workload and stress due to operating into a new airport with challenging surrounding terrain.
- The use of a tight visual approach circuit for runway 12 that did not meet stabilized approach criteria.
- A lack of appropriate technical and simulator-based training for the crew regarding the specific requirements of the new airport.
- Failure to follow standard operating procedures, including a lack of sterile cockpit discipline and ineffective crew resource management (CRM).
- The crew failed to notice the engine and flight deck indications that signaled the propellers had been feathered.
- The visual approach circuit was utilized without a formal evaluation or validation of the specific threats posed by the local terrain.