An aircraft that crashed in Nepal last month, killing 71 people on board, had no thrust motion in its engines in the final leg of its descent, a government-appointed panel investigating the accident says.

The plane crashed just before landing in the tourist city of Pokhra on January 15 in one of Nepal’s worst airplane accidents in 30 years.

There were 72 passengers on the twin-engine ATR 72 aircraft operated by Nepal’s Yeti Airlines, including two infants, four crew members and 10 foreign citizens.

Rescuers recovered 71 bodies, with one unaccounted person presumed to be dead.

Analysis of the cockpit voice recorder and flight data recorder showed the propellers of both engines went into “feather in the base leg of descending,” the panel said in a statement.

Aviation expert KB Limbu said propellers going into feather meant there was “no thrust” in the engine, or that it did not produce any power.