A plane crash in Nepal that claimed the lives of 72 people, including two infants, is believed to have resulted from the pilots mistakenly cutting the power, according to a report by government-appointed investigators.
This action led to a loss of thrust, resulting in an “aerodynamic stall.”
The Yeti Airlines flight was en route from the capital Kathmandu to the tourist town of Pokhara on 15 January.
It marks the country’s deadliest plane crash in 30 years.
The flight on 15 January, involving an ATR 72, was the crew’s third sector of the day, shuttling between Kathmandu and Pokhara.
The privately owned plane crashed in the Seti river gorge just 1.5km (0.9 miles) from the airport, triggering a rescue operation that involved hundreds of Nepalese soldiers.
“Due to its momentum, the aircraft flew for up to 49 seconds before hitting the ground,” said aeronautical engineer Dipak Prasad Bastola, a member of the investigating panel.
The pilots likely placed the condition levers, which control power, in the feathering position instead of selecting the flap lever, causing the engine to “run idle and not produce thrust,” Mr. Bastola explained.
“Following the unintentional feathering of both engine propellers, the flight crew failed to identify the problem and take corrective actions despite the Crew Alerting Panel cautions,” the report noted.
The report also cited a lack of appropriate technical and skill-based training, high workload and stress, and non-compliance with standard operating procedures as contributing factors to the accident.
It added that the aircraft had been properly maintained, had no known defects, and that the cockpit crew had been qualified according to the rules and regulations of the Civil Aviation Authority of Nepal.
More than a dozen investigators from the US, Canada, France, and Singapore were involved in the investigation.
“By the time I was there, the crash site was already crowded. There was huge smoke coming from the flames of the plane. And then helicopters came over in no time,” said a witness.
For the past decade, the European Union has banned Nepalese airlines from its airspace over safety concerns.
Aviation accidents are not uncommon in Nepal, often due to its remote runways and sudden weather changes that can create hazardous conditions. Last May, Tara Air Flight 197, owned by Yeti Airlines, crashed into a mountainside, claiming the lives of 22 passengers and crew.