Nepalese authorities say an instructor pilot on the Yeti Airlines ATR72 that crashed in Pokhara in January may have inadvertently feathered both props while trying to lower the flaps. The plane crashed while on final for the new airport in the Nepalese resort town and was a familiarization flight for the other pilot. A translation of the Nepalese Aircraft Accident Investigation Commission preliminary report says data from the cockpit voice and flight data recorder suggests that as the crew set up for landing, the instructor pilot pulled the wrong lever. The flap and prop levers are next to each other in the ATR72.
“At 10:56:27, the PF (Pilot Flying) disengaged the Autopilot System (AP) at an altitude of 721 feet Above Ground Level (AGL). The PF then called for ‘FLAPS 30’ at 10:56:32, and the PM (Pilot Monitoring) replied, ‘Flaps 30 and descending,’” the report said. “The flight data recorder (FDR) data did not record any flap surface movement at that time. Instead, the propeller rotation speed (Np) of both engines decreased simultaneously to less than 25% and the torque (Tq) started decreasing to 0%, which is consistent with both propellers going into the feathered condition. When propellers are in feather, they are not producing thrust.”
Video shows the aircraft slowing and then falling off to the left. It crashed on the edge of a gorge and all 71 people onboard were killed. Weather was benign at the time. The airport had been open for less than two weeks and Yeti was one of the first carriers to use it. Both pilots were captains and the pilot flying was doing a checkride into the new facility. The new airport has an 8200×150 runway.