Russian investigators on Thursday blamed pilot error for the plane crash that killed 96 poeple in Russia last Saturday, including Polish President Lech Kaczynski.

Initial findings indicated that the pilot attempted to land the plane in heavy fog near Smolensk on his own initiative, despite warnings from air traffic controllers.

Pilot error

A source close to the investigation told Russia's Interfax news agency that the pilot was apparently not fully familiar with the particularities of the TU-154 jet, which dropped at a rate the pilot couldn't control during landing.

If the TU-154's "speed of descent is more that six meters per second, when the plane equalizes and goes into a horizontal flight it loses altitude," the source said..

Accounts have also surfaced, based on black box recordings, that the crew knew of their impending doom.

"The crew was aware of the inevitability of the coming catastrophe, if only due to the plane shaking after the wings hit the trees, which we are certain happened," Poland's chief prosecutor Andrzej Seremet told TOK FM radio

Since the crash, there has been speculation over whether President Kaczynski placed pressure on the pilot to land in the fog. The speculation is based on reports that Kaczynski had sharply criticized his crew in 2008 when the pilot refused out of safety concerns to make a landing in Georgia, where the president wanted to show his solidarity with the country during its brief war with Russia.

Protests over burial site

Mourning in Poland has been disrupted by a public dispute over the president's burial location.

The state ceremony for the presidential couple is set to take place Sunday in the cathedral at Wawel Castle in Krakow, where Polish kings, national heroes and a saint are buried - an honor many do not want given to the nationalistic president and his wife.

On Wednesday, 2,000 people gathered in Warsaw to protest, and more than 42,000 people have joined a Facebook group against the plans.

This dispute has not deterred thousands from visiting the remains of the president and first lady, which will lie in state at the presidential palace through Saturday.

More clouds on the horizon

As of now it remains unclear whether the Sunday funeral plans will go through as planned, due to the ash cloud that has filled European airspace and caused airport shutdowns across the continent since the eruption of an Icelandic volcano on Wednesday.

More than 80 foreign flights carrying foreign dignitaries, including German Chancellor Angela Merkel, as well as Russian, French and US presidents, are slated to land in Krakow Sunday morning before the funeral. The remains of the couple themselves are also set to be flown into Krakow from Warsaw.

Poland closed most of its airspace Friday morning and shut all of its airports, including the airport in Krakow. Only one airport in the southern town of Rzeszow remains open.

While there had been some talk of postponing the funeral, presidential chanceller spokesman Jacek Sasin has told reporters that the family does not want to change the date "under any circumstances."

"We hope that all circumstances will be in place for the (foreign) delegations to attend," Sasin added.

dl/dpa/AFP/Reuters

Editor: Martin Kuebler