The memory card in the flight recorder of a Russian fighter plane downed by Turkey on the Syrian border last month is damaged, Russian investigators say.<br />The "black box" of the Su-24 jet was officially opened in Moscow on Friday in front of journalists and diplomats.<br />Nikolai Primak, head of the Russian investigation, said flight information appeared to be missing.<br />Data from the box could help resolve the dispute over the jet's location when it was hit.<br />An analysis is expected to be released next week.<br />The downing of the jet plunged relations between Russia and Turkey into crisis, with Moscow imposing sanctions in response.
