Pakistan International Airlines (PIA) says the flight crew of the crashed ATR 42-500 had made a mayday call and reported the failure of an engine before the turboprop lost contact with air traffic control.
The airline tells FlightGlobal that the aircraft's flight data recorder has since been recovered and handed to the Pakistan Civil Aviation Authority.
The search is still on for the voice recorder, it adds.
The Pratt & Whitney PW127E-powered aircraft - identified by ATR as MSN 663, with registration AP-BHO - was operating flight PK661 on 7 December when the incident happened. This was a domestic service between Chitral and Islamabad, and the aircraft crashed into the mountains near Havelian at around 16:40 local time.
All 42 passengers and five crew members on board perished.
"An inquiry has been ordered into the incident," says PIA in its statement.