The first analysis of the Polish presidential plane's black boxes led to the conclusion that there has been a piloting error, a source close to the Russian investigation team informs, quoted by AFP. On Saturday, April 10, Polish President's aircraft, carrying 96 people on board, crashed in Smolensk, Russia, after several failed landing attempts. Everyone on board died.

"One analysis of the proofs, including the first results from decoding the black boxes, indicates that a piloting error has led to the disaster", the quoted source said.

Russian official have already announced that they excluded the possibility for the tragedy to have been triggered by a fire or an explosion.

The accident killed the Polish President, his wife, the Polish bank Governor, the Foreign Affairs vice-minister and several tens of Polish elite.