Findings of the Polish Parliamentary Committee for the Investigation of the Smolensk Crash
According to the IAC Final Report, “the aircraft collided with the birch with a trunk diameter of 30–40 cm, which led to the left outer wing portion of about 6.5 m ripped off and intensive left bank. In 5–6 more seconds, inverted, the aircraft collided with the ground and was destroyed.”71 Accordingly, the encounter with the birch that resulted in the loss of a part of the wing caused the plane to invert and crash. This scenario was illustrated by an animation demonstrating IAC's interpretation of the last moments of the airplane before the crash. This animation was not supported by any scientific or forensic analysis of the crash scene, but rather represented a work of art contrary to basic law of physics.
On September 8, 2011, Dr. Wieslaw Binienda, an expert on high-energy impacts on materials and structures testifying before the Polish Parliamentary Committee, proved beyond a reasonable doubt that the collision with the birch could not have ripped the outer portion of the wing from the aircraft. While applying all parameters presented in the IAC Final Report in a rigorous finite element analysis, he demonstrated through a virtual experiment that the high-energy impact causes the wing to act like an ax, cutting the birch with only a small amount of damage to the edge of the wing but without any damage to the lifting area of the wing.72 These findings directly challenged the scenario presented by the IAC.
70 Ścios, Zbrodnia Smoleńska, p. 73.
71 Findings No. 3.1.69 and 3.1.70, IAC Final Report, English translation, p. 180.
72 Wieslaw Binienda, „Czy brzoza w Smoleńsku mogła złamać skrzydło Tu-154M 10 kwietnia 2010 roku?” as posted on November 7, 2011 at
PREZENTACJA EKSPERTÓW PRZED ZESPO?EM PARLAMENTARNYM, 08.09.2011 - Marek D?browski: ""Merde!" Cambronne, 1815" - Salon24.
Smolensk Status Report November 2011
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However, even if the scenario presented by the IAC is assumed whereby the birch rips off 1/3 of the length of the wing at the height of 6.5 meters from the ground, the ripped-off portion of the wing could not have fallen as far as 111 meters from the birch where it was found. The aerodynamic simulation shows that the ripped off part would crash to the ground no further than 12 meters from the birch at velocity of 100 km/h. The inspection of the crash scene showed that the ripped off portion of the left wing was found leaning against the trees 111 meters from the birch and on the right side of the path of the airplane. The observed damage to the trees and to the ripped off segment of the wing excludes the possibility of a velocity of 100 km/h at the point of impact.