Investigation Summary
The flight was a short domestic hop from Kathmandu to the newly opened Pokhara International Airport. The crew consisted of an instructor pilot in the right seat and a captain undergoing aerodrome familiarization in the left seat. During the final approach to runway 12, a demanding procedure that had not been formally briefed or approved by the regulator, the pilot flying (PF) requested 'Flaps 30'. The instructor pilot (PM), likely due to high workload and the physical proximity of the controls, inadvertently moved the condition levers to the feathered position instead of the flap lever. This immediately eliminated thrust and caused the propeller rotation speed (Np) to drop below 25%. Despite a Master Caution chime and multiple amber alerts on the Crew Alert Panel (CAP) indicating hydraulic and electrical failures (due to the loss of AC Wild generators driven by the propellers), the crew did not perform a go-around. The PF noted a lack of torque and power, but the crew did not cross-check the engine instruments or the position of the condition levers. As the aircraft turned onto the final approach path, the airspeed decayed until the stick shaker activated. The aircraft banked steeply to the left and impacted the ground just 2 km from the runway threshold.
Final Conclusions
The Nepal Aircraft Accident Investigation Commission (AAIC) released its final report on 28 December 2023. The primary cause was the inadvertent movement of both condition levers to the feathered position, resulting in a loss of thrust and a subsequent aerodynamic stall. Contributing factors included high pilot workload associated with operating into a new airport, ineffective crew resource management (CRM), non-compliance with standard operating procedures (SOPs), and the lack of a sterile cockpit. The report also highlighted that the visual approach circuit for runway 12 had not been properly evaluated or approved by the operator or the regulator before being put into use.
Photographic Evidence (1)
Video Analysis
Yeti Airlines Flight 691: Last Moments Revealed - Cockpit Conversation & Crash Analysis! — An analysis of the cockpit voice recorder transcript and flight data from Yeti Airlines 691, explaining how the condition levers were mistakenly feathered during the approach to Pokhara.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain (Instructor)
Occupying the right seat as Pilot Monitoring (PM). Identified as Captain Kamal KC.
Captain (Trainee)
Occupying the left seat as Pilot Flying (PF) for aerodrome familiarization. Identified as Captain Anju Khatiwada.
Systems & Failure Modes
Condition Levers
Controls fuel shut-off and propeller feathering. On the ATR 72, these levers are located on the center pedestal next to the flap lever.
AC Wild Generators
Generators driven by the propeller gearbox. When the propellers feathered and slowed, these generators stopped providing power, triggering electrical and hydraulic alerts.
Stick Shaker
A mechanical device that rapidly vibrates the control yoke to warn the crew of an impending aerodynamic stall.
Interesting Facts
- 01The accident was the deadliest aviation disaster in Nepal since 1992 and the deadliest involving an ATR 72.
- 02The crash occurred only two weeks after the opening of Pokhara International Airport.
- 03A passenger on board live-streamed the final moments of the flight on Facebook.
- 04The instructor pilot had previously landed at the new airport only twice.
- 05The aircraft involved, 9N-ANC, was manufactured in 2007.
- 06The 72 fatalities included 57 Nepalese (53 passengers and 4 crew) and 15 foreign nationals from India, Russia, South Korea, Argentina, Australia, France, and the United Kingdom.
- 07The pilot flying, Captain Anju Khatiwada, had lost her husband, Dipak Pokhrel, in the 2006 Yeti Airlines Twin Otter crash.
Safety Actions & Advisories
Visual Approach Standardization
The investigation recommended that all visual approach procedures for new airports be formally evaluated, validated, and published in aeronautical charts before use.
CRM and Technical Training
Yeti Airlines was advised to enhance Crew Resource Management training and provide specific simulator training for engine failure and feathering scenarios during critical phases of flight.
Location
ACCIDENT SITE · Coordinates taken from the official investigation report.