Russian Prime Minister Dmitry Medvedev ordered officials on Monday to examine whether Russia's flight safety rules need to be tightened up after a passenger jet crashed in southern Russia killing all 62 people on board.
Investigators were trying to repair the damaged voice recorder recovered from the plane, so they could recreate the conversations of the pilots in the moments before their Boeing 737-800 slammed into the ground.
The plane, operated by Dubai-based budget carrier Flydubai, crashed in the early hours of Saturday at Rostov-on-Don airport in southern Russia in strong, gusting winds on its second attempt to land.
Medvedev told the government to analyze the reasons behind the crash.
"If there are some technological issues, then they should be analyzed and, at the conclusion of that analysis, proposals should be made to the government so that some amendments can be made to technical equipment, if that's needed, or to the rules that exist in our country's aviation," he said, without elaborating.
The stricken plane's flight data recorder survived largely intact, but the cockpit voice recorder - which should shed light on the pilots' final conversations before the crash - was badly damaged and needs to be restored.
That process could take weeks, officials have said.
There is so far no suggestion of terrorism.
Russian media say the two main theories under consideration by investigators are possible pilot error or a technical failure.
Flydubai's CEO Ghaith al-Ghaith said on Saturday it was too early to determine why the plane, which was just over five years old, crashed.
One of the big unanswered questions is why the plane attempted to land in what were reported to be fiercely strong winds and did not divert to a nearby airport. An Aeroflot plane had earlier made several aborted landing attempts and been diverted.
Investigators are likely to focus, among other issues, on how the decision to land was reached, why the plane circled above the airport in a holding pattern for over two hours, and on the precise thinking of the pilots and the airport's landing tower.