Preliminary inquiries into the fatal Airblue Airbus A321 accident outside Islamabad last month suggest the aircraft suffered no technical problems before the crash.
Flight ED202 had been attempting to land at the Pakistani capital on 28 July but struck terrain north of the airport.
Both the cockpit-voice and flight-data recorders have been successfully read by the French investigation agency Bureau d'Enquetes et d'Analyses.
This information has enabled investigators to "determine a preliminary analysis", says a source familiar with the inquiry.
"It is fair to say that the [investigators] should have everything they need to understand what happened," the source states, adding that there is "no indication of any technical malfunction".
"The cause of this accident seems to be on the operational side."
Airbus has informed operators of A320-family aircraft that it has "no specific recommendation to raise", effectively a statement that nothing points to a need for carriers to make technical checks or modify their operations.