The plane carrying the Polish delegation was on its way to Russia for a ceremony to mark the 70th anniversary of the Katyn massacre.
This was the killing of thousands of Poles by Soviet forces during the Second World War.
There were no survivors when the plane, carrying 96 passengers and crew, crashed into trees in heavy fog.
Media reports in Russia at the time said the pilots ignored advice from local air traffic controllers to change course and land at a different airport.
The crash left Poland in a state of shock, with the president and his wife and many other senior officials killed: the army chief, the head of the central bank, numerous politicians, senior civil servants and academics.
Controversy surrounded the different investigations into the tragedy, with tensions emerging between the two countries over access to evidence and how the inquiries were being handled.