Flight PK-661 went down on its way from Chitral to Islamabad.
All on board, including the famous pop singer turned Islamic preacher, Junaid Jamshed, died when the plane crashed in the Havelian area, about 70km (43 miles) north of Islamabad.
The national carrier has been accused of safety failures in the past.
But Pakistan International Airlines chairman Azam Sehgal, who confirmed there were no survivors at a press conference late on Wednesday, said the strict regime of checks carried out on the aircraft left "no room for any technical error".
"It is a tragic accident and we are not trying to absolve ourselves of responsibility," he said. "We accept that it was our aircraft, and these were our passengers, and what happened is very sad."
Mr Sehgal said the company would be carrying out an investigation but the "focus at the moment is to retrieve dead bodies from the wreckage, transport them to Islamabad and hand them over to their families".