Poland's new defense minister, Tomasz Siemoniak has fired three air force generals and 10 other top officers following an investigation into the plane crash last year that killed president Lech Kaczynski.

The defense minister also said Thursday that the air force unit responsible for transporting top officials will be disbanded.

Siemioniak's predecessor, Bogdan Klich, quit Friday after a Polish inquiry commission found that the military crew of Mr. Kaczynski's plane was poorly trained and ill-prepared. The commission report said the pilots made a series of errors and violated procedures before the crash.

President Kaczynski, his wife and 94 other passengers and crew died on April 10, 2010, when the presidential jet crashed near Smolensk in western Russia.

Most of Poland's military leaders were aboard the plane, which was bound for Smolensk for a memorial ceremony commemorating the Katyn forest massacre in 1940 of about 22,000 Polish military officers. At the time, the Soviet Union blamed Nazi Germans for the mass killings; only in recent years did Russian leaders admit that Soviet forces carried out the massacre.

Poland's investigation of the plane crash in Russia was released last Friday, more than 15 months after the tragedy.

A Polish government commission blamed the crash on a combination of factors, including heavy fog and errors the pilots made in handling the Russian-made (Tupolev 154) airplane. The report also cited the Polish crew's hasty, haphazard training for the flight, poor information about weather conditions and problems in their dealings with Smolensk airport.

Russian investigators have said their separate analysis showed the direct cause of the flight was the Polish crew's failure to turn away from fog-shrouded Smolensk and head for a different airport.