The plane with Spanish soldiers on board crashed in the north east of Turkey.
As has been reported by Spanish television, there were 74 people on board the supposedly Ukrainian plane - 62 of them were Spanish servicemen who were returning from Afghanistan to Madrid.
The plane was to land in Turkey for refuelling.
The accident took place in the area of the city of Trabzon, some 30 kilometres off the Black Sea shore.
The causes of the crash has not yet been established.
The aircraft to command and control troops in the event of a nuclear war is being built on the basis of the new wide-body Ilyushin Il-96-400M