"

 rework begun 

I suggest to rework the ""Initial theories"" section along these line:

First
First I suggest to delete the Technical failure section and move the relevant information (that the plane was fine) to the Investigation section under a new title and with the following text:

 The Plane 

The aircraft, a Tupolev Tu-154M, construction number 90A837, was manufactured at Kuibyshev aviation plant (No. 18) on 29 June 1990 for the Polish Air Force.
It was one of two Tupolev Tu-154s that served as official government jets; this aircraft—with a tail number of 101—was for presidential use, while another—marked 102—is used by the prime minister. The aircraft had undergone a major overhaul in December 2009 and Aleksey Gusev, the head of the maintenance plant that carried out the work, told Polish TV that it should not have had technical problems. The airplane had received a 5-year/7500-flight-hour warranty after the overhaul yet the crash happened after just 138 flight hours.

Second
As second part of the rework I suggest to edit half of the VIP passenger syndrome section away and put the remaining paragraph last in the section Investigation:

There has been some speculation in the press, that the planes pilot was under pressure to land in Smolensk in spite of the averse weather conditions. These speculations were linked to an earlier event in August 2008, when another pilot of the 36th Special Aviation Regiment was pressured by president Kaczyński to land in Tbilisi during the South Ossetian war between Georgia and Russia. During that incident, Pietruczuk was asked by the president's staff to change the flight plan and land in Tbilisi. After consulting with the commander of his unit, Pietruczuk refused, justifying his decision by safety concerns. He was then visited in the cockpit by Kaczyński himself, who tried to convince him to change his mind. Kaczyński later told journalists: ""If someone decides to become an officer, they should not be cowardly"". Nevertheless, Pietruczuk held his ground and the plane landed in Azerbaijan as planned. A few weeks after this incident Pietruczuk was decorated by the defense minister for following correct procedures in this case and keeping the safety of his passengers utmost in his mind. Pietruczuk continued to fly the president's plane after the incident, even after Kaczyński expressed unhappiness with his performance during the flight to Tbilisi.

Third
Thridly I would shorten the Instrument landing system incompatibility section, rename it and definitely delete the ""may be using"" part and put the resulting section directly under the the section ""The