Downed warplane's damaged black box 'not yet' readable

Further attempts to read the flight recorder would take 'quite a long time'

Russian military officials said on Monday they would call on more specialists to help decipher the damaged black box of a warplane shot down by Turkey after a first attempt to read the device failed.

"Reading the memory cards is not yet possible due to internal damage," said Sergei Bainetov, the deputy head of flight safety in the Russian armed forces, RIA Novosti reported.