Russian plane had abnormal device function

“There was no explosion on board, I can say that for certain,” said Sergei Bainetov, head of flight safety for the Russian airforce. “But an act of terror is not necessarily an explosion, so we are not discarding this version.” 

Maxim Sokolov said the probe has established that the plane was not working normally but will not issue any conclusions before Jan, cautioning journalists not to jump on any theories. “It is obvious that the equipment was functioning abnormally, but why that happened is up to experts,” he said