Smolensk air disaster


The Smolensk air disaster occurred on 10 April 2010, when a Tupolev Tu-154 aircraft of the Polish Air Force crashed near the Russian city of Smolensk, killing all 96 people on board. Among the victims were the President of Poland Lech Kaczyński and his wife Maria, the former President of Poland in exile Ryszard Kaczorowski, the chief of the Polish General Staff and other senior Polish military officers, the president of the National Bank of Poland, Polish Government officials, 18 members of the Polish Parliament, senior members of the Polish clergy and relatives of victims of the Katyn massacre. The group was arriving from Warsaw to attend an event commemorating the 70th anniversary of the massacre, which took place not far from Smolensk.
The pilots were attempting to land at Smolensk North Airport—a former military airbase—in thick fog, with visibility reduced to about. The aircraft descended far below the normal approach path until it struck trees, rolled inverted and crashed into the ground, coming to rest in a wooded area a short distance from the runway.
Both the Russian and Polish official investigations found no technical faults with the aircraft, and concluded that the crew failed to conduct the approach in a safe manner in the given weather conditions. The Polish authorities found serious deficiencies in the organization and training of the Air Force unit involved, which was subsequently disbanded. Several high-ranking members of the Polish military resigned, under pressure from politicians and the media.
Various conspiracy theories about the crash have since been in circulation, and are promoted by Law and Justice's leaders Jarosław Kaczyński and his deputy, Antoni Macierewicz, who claim the crash was a political assassination. Polish and international investigations did not find any evidence supporting this claim.

Background

Purpose of the flight

The flight's purpose was taking many high-ranking Polish officials to ceremonies marking the 70th anniversary of the Katyn massacre, a mass murder of Polish intellectuals, politicians, and military officers by the Soviets during World War II. The site of the massacre is approximately west of Smolensk. The area is fairly remote; Smolensk is the only city nearby and has the only two airports in the area: Smolensk North Airport, where the accident occurred, and Smolensk South Airport.

Destination airport

is a former military airbase, presently in mixed military-civilian use. At the time of the crash, the airport was not equipped with an ICAO-compliant instrument landing system, the standard system used in most developed countries. The airport used to have a Russian-made landing system installed, which was decommissioned after civilian operations started. The Polish Tu-154 was modified to use western-style ILS. A non-directional beacon was installed at the airport, but such a device is essentially a navigational aid, and can be used only for non-precision approaches, where it can guide the pilot to align with the runway, but offers no vertical guidance on how to descend towards the runway. The airport was equipped also with both a surveillance and landing radar. The lowest approved visibility conditions to land were cloud base and visibility.
The ground visual navigation aids on 10 April 2010 were not effective. According to the Polish report, the radar was unstable and swung within ±10%. From the photographic documentation of the Polish committee, it appears that the origin of components of the Smolensk North lighting system was unknown. This was not the Luch-2MU system as the Russians stated. The report from the inspection flight performed on 15 April 2010 stated that the approach lamps, depending on their location and on the altitude of an inbound aircraft, can be shaded by surrounding trees and shrubs when an aircraft is at a distance of 400, 700, and 800 metres from Runway 26. The lamps of the first group had their light filters shattered and, of three bulbs installed, only one was serviceable.

Aircraft

The aircraft was a Tupolev Tu-154M of the 36th Special Aviation Regiment of the Polish Air Force, tail number 101. Built in 1990 at the Kuybyshev Aviation Plant as msn 90A837, it first flew on 29 June 1990. At the time of the accident, the airframe had accumulated more than 5,150 hours in 4,000 cycles. The service life of the Tu-154M is more than 25 years or 30,000 hours or 15,000 cycles. All three Soloviev D-30KU-154 engines were within the service limits of 24,000 hours or 11,100 cycles.
"101" was one of two Tupolev Tu-154s that served as official government jets; the other with a tail number of 102 was a year younger and at the time of the accident it was being overhauled in the Aviakor aviation plant in Samara, Russia. The "101" aircraft had undergone a major overhaul in December 2009, and Alexey Gusev, the head of the maintenance plant that carried out the work, told Polish TV that it should not have had technical problems. The crash happened 138 flight hours after the most recent overhaul.
The aircraft used the callsign PLF 101. PLF is the ICAO three-letter designator for the Polish Air Force used to identify the operator of an aircraft by air traffic control.

Crew

The cockpit crew consisted of pilot Captain Arkadiusz Protasiuk, co-pilot Major Robert Grzywna, navigator Lieutenant Artur Ziętek and flight engineer WO2 Andrzej Michalak. Protasiuk had landed at Smolensk three days earlier on 7 April in the same Tu-154; he served as first officer on that flight. Protasiuk had 3,531 flight hours, including 2,906 hours on the Tu-154. Co-pilot Grzywna had 1,909 hours, with 475 of them on the Tu-154. Ziętek had 1,050 hours, only 58 of them on the Tu-154. Michalak had only 329 hours, all on the Tu-154.

Flight sequence

Take-off and cruise

PLF 101 took off from Warsaw at 9:27 Smolensk time after a delay of 27 minutes.
As the aircraft left Warsaw, weather conditions were rapidly deteriorating at Smolensk. A temperature inversion had developed, trapping moisture low in the atmosphere and causing a dense fog to develop. At 9:15 Smolensk time, about an hour and a half before the crash, a Yakovlev Yak-40 jet also belonging to the Polish government and carrying Polish journalists from the President's press pool landed at the airbase without incident, though conditions were rapidly worsening at the time. Shortly thereafter, between 9:20 and 9:39 MSD, a Russian Ilyushin Il-76 made two attempts to land, but because of low visibility, it diverted to Vnukovo Airport near Moscow. Upon PLF 101's approach to the base, atmospheric conditions continued to worsen, and the fog continued to thicken, further reducing visibility to. The ground control personnel stated to PLF 101 that there were no conditions for landing. The Captain then requested and was given permission to conduct a "trial" approach. The controllers instructed the captain as to the landing minimum of, to which the captain replied, "Yes, sir!"

Stress and workload factors

Meanwhile, the situation in the cockpit was one of very high stress. As the weather continued to worsen, the crew became increasingly aware of the extreme difficulty they would encounter in landing at Smolensk. The crew may have feared a negative reaction from their passengers should they have to divert to an alternative airfield. The protocol director was present in the cockpit from time to time, and the Commander-in-Chief of the Polish Air Force was present in the cockpit for the final approach phase of the flight, including the crash itself. At one point, the navigator is heard on the CVR saying "He'll go crazy", a possible reference to the President of Poland, had the crew chosen to divert. There may also have been some friction between the Air Force Commander and the captain, caused by an absence of the latter from condition training.
The captain and first officer's decision making may have also been affected by knowledge of a 2008 flight when the President of Poland ordered a change in destination right before departure and again while airborne. The captain and first officer had been the first officer and navigator, respectively, on that flight. Lacking charts or a flight plan for the new destination, the captain of that flight had decided he could not bring the aircraft to the new destination safely. Disobeying the President and a high-ranking Polish Air Force commander on board, the captain flew on to the originally planned destination. The Polish prosecutor's office would later clear that captain of any wrongdoing in relation to that flight, and he was even awarded a silver medal of merit for national defense. However, in the final report issued by MAK – a supervising body overseeing the use and management of civil aviation in the Commonwealth of Independent States, it was stated he had not been assigned to fly the President since, though Polish sources note he flew the President to New York in September 2008, despite objections from the President. The captain involved in the 2008 incident flew the Polish Prime Minister to Smolensk on 7 April without the President on board, but he was removed from the crew of the 10 April flight which carried the President. Knowledge of the 2008 incident and its repercussions may have weighed on the crew of PLF 101, potentially placing additional pressure on them to complete their flight to the original destination.
Complicating the situation was the increased workload on the captain. Normally, one pilot flies the airplane while another crew member handles radio communications. On PLF 101, the responsibility for communication usually rests with the navigator. At Smolensk however the situation was different. As the airport is not usually open for international flights and is not ICAO certified, the air traffic controllers were not required to be fluent in English, the ICAO standard language for ATC communication. As such, all communication between Smolensk ATC and PLF 101 was carried out in Russian. Russian law requires international flights landing at military airports to have a Russian "Leaderman" on board the flight, who is then responsible for all ATC communication, which is done in Russian. In the middle of March, as part of their request for permission to conduct the flight, Poland asked for "Leaderman" services and the latest airport data for Smolensk. At the end of March, after apparently receiving no reply to their first request, Poland tendered a second request for permission to fly, but did not request "Leaderman" services. As a spokesperson for the Air Force Command said: "The Russian side has not confirmed readiness to secure the flight leader". According to the Final Report, Russia did offer "Leaderman" services, but Poland refused, stating their crew had satisfactory knowledge of Russian and could conduct the flight without the Leaderman. In reality, the captain was the only member of the crew who could speak adequate Russian. Therefore, upon being handed off to Smolensk ATC, the captain took over communication duties from the navigator. In a normal situation, this would dictate that the first officer be the pilot actually flying the airplane, but as the weather was bad the captain, as the most experienced member of the crew, elected to fly the airplane as well. Therefore, the captain was performing two tasks simultaneously which are usually split up, increasing his workload and requiring him to divide his attention.

Approach

Under these stresses, the crew continued their approach pattern and readied the aircraft for final descent. Radios were tuned to the two Non-Directional Beacons present at the field, and the autopilot was set up to use waypoints from the Flight Management System units for navigation. The crew used their second radio to contact the Yak-40 which had landed earlier, inquiring as to the weather conditions. The Yak-40 crew replied, "Well, generally it's absolute shit here," and that, " were lucky to land at the last moment." The Yak-40 crew estimated visibility was, but told PLF 101, "you might try...." The crew of PLF 101 acknowledged this information and continued their approach. As the aircraft approached the outer marker, the crew issued pitch commands to the autopilot. This is not recommended for the Tu-154, as the autopilot cannot maintain vertical speed accurately enough for the approach phase of flight; manual flight mode is instead recommended. Although the crew had not requested it, the radar controller began issuing reports to PLF 101 concerning their distance from the runway and whether or not they were on the glidepath. The Polish report noted that on multiple occasions the radar controller stated the airplane was on the glidepath when it was not.
The Terrain Awareness Warning System fired its first audible warning "terrain ahead!" at 10:40:06. This was because the Smolensk airport, as a former military airfield not open to international flights, was not in the system's database and therefore the system did not recognize that the airplane was approaching an airport. Six seconds later, someone pressed a button on the captain's FMS panel commanding standard barometric pressure be set on the captain's main electronic altimeter. This had the effect of increasing the altimeter's reading by ; as the TAWS takes readings from this particular altimeter, this had the additional effect of silencing the warning. The captain's secondary and the copilot's main electronic pressure altimeters continued to read correctly. As the descent continued, the crew realized they had started descent too late. To compensate for this, they increased their vertical speed to, twice the prescribed rate for a normal approach. The aircraft did not have enough drag to maintain speed with this rate of descent, so even though the autothrottles commanded idle power from the engines, the speed of the aircraft increased to approximately higher than specified.
Approaching, the navigator began calling out the radar altimeter's reading. This is not standard practice for a non-precision approach, as the radar altimeter does not take into account the contour of the terrain around the airport. Standard practice would entail calling out the readings on the pressure altimeter, which is set according to atmospheric pressure and thereby references the elevation of the actual airport. The terrain on approach to Smolensk airport is uneven and locally much lower than the runway level.

Warning signs

At, the engines were still at idle power. Power settings for jet engines are expressed in instrument readings and flight data recorders as percentages labeled as "N1" and "N2". N1 and N2 refer to the spools, or shafts, of a jet engine on which the compressor and turbine blades are mounted; jet engine power is measured as a percentage of maximum N1 or N2 rpm. Although the shafts are not mechanically connected, the speed of one spool can be calculated based on the speed of the other spool and atmospheric conditions. The Tu-154 manual indicates that a go-around must be initiated at 200 m if the engines are running at or below 75% N2. This is because jet engine throttle response is not linear; jet engines have to "spool up" in order to produce more thrust. At power settings higher than 78%, this response is almost instantaneous; at idle power, it can take a full 8 seconds for a jet engine to "spool up" to full power. On PLF 101, the N2 values were not recorded by the flight data recorder. The N1 values were, and at 200 m they indicated 32–33% N1. 75% N2 equates to 51–52% N1 for the given conditions. As such, the engines were well below the 75% minimum N2 reading, and the crew should have initiated a go-around at this point, even though they were still above Decision Height. However, they did not go around, and continued the descent. The Final Report would later determine that a go-around was technically possible from as low as 40 m, but that 200 m was the first of many times that the crew were required to go around, but did not.
At, the "terrain ahead!" warning again sounded on the flight deck. The crew continued the descent. According to MAK's report, at there was no "landing" or "go-around" call by the captain. If this happens, the first officer is supposed to overrule the captain, take control of the airplane, and initiate a go-around. Poland suggests that at this point the captain said "Go around", and 8 seconds later the first officer confirmed by saying "go around".. Despite these calls, neither pilot initiated a go-around, and the descent continued. One second after the 100 m altitude was reached, the TAWS alert "PULL UP" activated and continued to sound for the remainder of the flight. "PULL UP" only activates when the TAWS computer believes a collision with terrain is imminent. Therefore, when "PULL UP" sounds, the crew is supposed to begin an immediate, maximum performance emergency climb and continue climbing until the warning stops. However, the crew continued the descent. In a typical situation with an airport in the TAWS database, the "PULL UP" warning might not have sounded at this point. There is a method of setting up the TAWS to prevent false warnings when flying into airports not in the database, known as "terrain inhibit" mode; however, the crew did not utilize it. Even if they had, an excessive rate of descent and excessive airspeed can cause the TAWS to issue a "SINK RATE" warning followed by a "PULL UP" warning. This point is also notable because this was the moment when the aircraft had crossed the minimum allowed approach slope for this airport. Prior to this moment, the radar controller had no reason to think that the landing attempt was not proceeding normally. The behavior of the controller was later the subject of some criticism by the Polish media. The controller remained silent for about 12 seconds after the aircraft passed the 100 m mark, and, even at that point, he did not order a go-around, but, rather issued an instruction to transit from a descent to a horizontal flight. In addition, according to some interpretations of the radio exchange between the ground and the aircraft, the crew was instructed by the ground control to descend to and either to wait for clearance to land or request one explicitly, or to inform the ground control regarding their decision whether to land or to go around. None of this ever happened, with the aircraft continuing the descent through the 120 m mark while the ground control remained silent. It is unknown whether the crew really understood the ground control instruction, which was issued in Russian and used a relatively recent expression that was only codified in 2006.
For the next several seconds, the crew continued to call out "100 meters" as read from the radar altimeter. The aircraft was flying into a valley at this time and actually descended by. The crew began calling out radar altitude every. At radar altitude, the First Officer called out "Go around". Due to the terrain in the area, the aircraft was actually only above runway level at the time. Simultaneously to this callout, the FDR recorded a brief pull on the control column, likely done by the first officer, as he instinctively started the go-around sequence of actions. According to the investigation, this attempt at a go-around was completely overridden by the auto-pilot, which was still active, and, in any event, it was not completed. Flight simulator testing by the investigation concluded that had the first officer completed a go-around at this point, the crash would likely have been avoided despite the violation of minimums and the excessive rate of descent. The investigation found that this was the last moment at which a go-around could have been successful.

Point of no return

As the crew called out "50 meters", the controller instructed "level 101", telling the aircraft to terminate descent. At, another controller instructed "Check altitude, level." Simultaneously with this final call, the control column was pulled full aft, commanding max pitch up from the aircraft, and the throttles were moved within one second from their flight idle positions to maximum power. The aircraft, due to the valley terrain, was actually below the runway at this time. The Russian investigation surmised that at this moment the flight crew saw the trees through the fog, and instinctively reacted in an attempt to escape their grave predicament. The crew did not disengage the autopilot, but the action of commanding maximum pitch up on the control column overpowered it, causing the pitch channel to disengage. The control column briefly moved to neutral at this point, then moved full aft and remained there for the duration of the flight. According to the Polish report, the command "level" ordering a change to horizontal flight was issued at a time when the aircraft was at an altitude of about above airfield level. Two seconds before the "level" command, the aircraft commander made the decision to go around. According to the Polish committee's findings, the command to level should have been issued 10 seconds sooner, when the aircraft was well below the glide path.
Soon after, the aircraft began hitting trees. One, a large birch with a trunk wide, ripped off about of the left wing, including the left aileron. The resulting asymmetrical lift caused an uncommanded roll to the left. Within 5 seconds, the aircraft was inverted, hitting the ground with the left wing, followed very shortly after by the nose. The nose impact resulted in forces exceeding 100g, which killed everyone on board instantly. Even without the birch tree and subsequent roll, the excessive angle of attack would have led to an aerodynamic stall approximately two seconds after impact with that tree, which would also have led to a fatal accident. According to the Polish report, safety areas around every aerodrome are mandated by international regulations to prevent situations where aircraft or aerodrome operation could be compromised by obstacles in the immediate vicinity. A thorough analysis of terrain reveals that obstacles were present in the safety area, with many trees exceeding the permitted height limit.
After the nose hit, the aircraft was violently torn apart by impact forces. The wreckage came to rest upside-down about before the runway threshold and slightly left of its centreline. The largest pieces left were the wing roots, the wingtips and the tail section. The tail section came to rest backwards, relative to the direction of flight. A small post-impact fire ensued, but was quickly brought under control by the emergency services and extinguished 18 minutes later.
The Governor of Smolensk Oblast, Sergey Antufyev, confirmed that there were no survivors of the crash. Pictures from the scene showed parts of the aircraft charred and strewn through a wooded area. The Russian Prime Minister, Vladimir Putin, said that the bodies of those killed in the crash would be brought to Moscow for identification. Kaczyński's body was identified in Smolensk and was flown directly to Warsaw on the afternoon of 11 April.

Initial investigation

As the accident occurred on Russian soil, Russia was tasked by ICAO procedure with primary responsibility for investigation, which it carried out with international cooperation. Poland also set up its own committee to investigate the crash, and prosecutors in both countries began criminal investigations.

Interstate Aviation Committee

In the Commonwealth of Independent States, the Interstate Aviation Committee oversees the use and management of civil aviation. The committee's Air Accident Investigation Commission is responsible for investigating civil aviation accidents occurring in commonwealth member nations. The committee is headquartered in Moscow, Russia.

Immediate actions

Within hours of the crash, the President of Russia, Dmitry Medvedev, announced the establishment of a special commission for the investigation of the accident. The commission was to be supervised by Prime Minister Vladimir Putin. An Investigation Committee of the Prosecutor General of Russia started a criminal case in accordance with a "violation of the safety rules" of the Russian Criminal Code.

Flight recorders

Two flight recorders, the cockpit voice recorder and the flight data recorder, were recovered undamaged from the crash site during the afternoon/early evening of 10 April, as was confirmed by Sergey Shoygu, the Russian Minister of Emergency Situations. That evening, it was reported that the CVR recordings confirmed the crew attempted to land against the advice of air traffic controllers. A third flight recorder, a Quick Access Recorder designed for maintenance diagnostics, was found on 12 April. The two Flight Management System units were also recovered. The investigation was able to obtain information from the electronic memories of the Quick Access Recorder and one of the FMS units, despite the fact that they were not designed to withstand a crash. Since the FMS units are linked together, being able to read the memory of one meant the investigation was able to determine the actions performed by both units. It would later be discovered that the FDR was partially defective and had occasional gaps in its data, but as the QAR managed to survive the crash, by synchronizing the data from the two units, a complete picture of flight data emerged.
On the day after the crash, investigators said they had reviewed the flight recorders, and confirmed that there were no technical problems with the Soviet-built aeroplane, ruling out initial theories that the 20-year-old aircraft was at fault. Alexei Gusev, general director of the Aviakor factory, said that the aircraft's three engines had been repaired and technicians had upgraded the plane's avionics at a recent overhaul the previous year. He said that there were no doubts about the plane's airworthiness.

Search for human remains

, former Polish Minister of Health, claimed before the Sejm that after the crash, ground was dug to a depth of one metre, and even if a tiny piece of human flesh was found, it was genetically tested. However, in the transcript released online by the Sejm, the meaning of her speech was changed: that when a small piece of flesh was found, the ground was dug to a depth of one metre. Moreover, in September 2010, one of the Polish pilgrims to Smolensk found a jaw with teeth and two other bones.

Russian cooperation

Russia offered full cooperation to Polish prosecutors during the investigation. According to the Interstate Aviation Committee Polish investigators in Russia have been given access to all procedures of Russian investigators. However, Edmund Klich, the head of the Polish investigative commission, said that "Poland does not have a lot of things that would like to have" and as an example gives lack of documentation of Smolensk airport and regulations about Air Control. Polish investigators do not have the authority to conduct investigative actions by themselves, but they participated on equal terms with their Russian counterparts in the interviews with people involved and other parts of the investigation. Polish officials were to secure all Polish state documents found in the wreckage, as well as electronic devices belonging to government officials and military officers. In turn Russian investigators received from Poland materials secured after the crash, including those about the technical state of the aircraft and fitness of the pilot. The Polish investigation results were to be based in part on Russian findings, but they are not bound by the results of the Russian investigation. Preliminary results of the investigations were to be released on the Thursday after the crash, but this was postponed until after the weekend when the funeral of the Presidential couple was to take place, then postponed indefinitely until the full analysis was completed. The Flight Data Recorder and Cockpit Voice Recorder, both of Soviet design, were analyzed in Russia with the participation of Polish experts. The Quick Access Recorder, designed and produced in Poland, was sent to Poland and analysed there, with the participation of Russian experts. The Flight Management System units, manufactured in the United States, were analyzed there with the participation of the FAA, NTSB, Polish experts, and Russian experts.

Airport and pilot communication

The airport's traffic control communicated with the pilots in Russian, and one of the controllers claimed the Polish crew had problems communicating in this language. However, according to Tomasz Pietrzak, the former commander of the Polish 36th Special Aviation Regiment, the captain of PLF 101 was fluent in Russian and English. The Captain had landed in Smolensk three days before the crash, when he was part of the crew bringing Polish Prime Minister Donald Tusk to the 7 April ceremony, and at the time no communication problems with ground control were reported. However, while the captain knew Russian, the rest of the crew did not, in particular the navigator whose task it is to communicate with the ground, thus placing an additional workload on the captain. Previous flights to Smolensk had been accompanied by a Russian navigator, but none was provided for the April 2010 flights, with differing reasons for this given by Polish and Russian sides. The final accident report would later conclude that the captain's knowledge of Russian was "satisfactory."
The airport, which normally should have been closed due to the severe conditions, was not declared closed as its management feared that this could cause a diplomatic incident. According to the news agency Interfax, the pilot was told that Smolensk North Airport was enveloped in thick fog and strongly advised against landing, but still he decided to continue with the original flight plan and attempt a landing. According to an interview with a flight controller Pavel Plusnin it was suggested to the pilot that he land at an alternative airfield in Moscow or Minsk. According to Plusnin, the pilot said, that he would attempt one approach, and if landing was not possible, he would then divert to another airfield.
There was some concern in the press as to whether or not Russian military ATC had the authority to issue military orders to PLF 101, as the aircraft was a military flight. Under Russian law, military flights are under the control of Russian military ATC, and permission or denial for approach and landing must be given by the controller prior to these actions being undertaken by a flight crew. The final accident report determined that, as a foreign military aircraft, Russian controllers did not have the authority to issue military orders to PLF 101, and this had been communicated to the ATC personnel who handled the flight. The "trial" approach was conducted with the understanding by ATC that all risk for such an approach was to be undertaken by PLF 101 and not ATC.

Theft from victims

On 6 June 2010, it was reported that payments worth €1,400 had been made from a credit card found on the body of historian Andrzej Przewoźnik, one of the victims of the crash. Credit cards belonging to the politician Aleksandra Natalli-Świat were also missing, but not used in transactions. On 8 June 2010, ITAR-TASS reported that four soldiers of Unit 06755 had been charged in connection with the theft, after being found in possession of three credit cards used to withdraw a total of 60,345 rubles. A Polish spokesperson said that the first withdrawals using the cards had been made around two hours after the crash. The Polish government admitted that the Russian soldiers involved in the theft were probably conscripts, and that earlier reports blaming members of Russia's OMON forces for the theft had been a mistake.

Initial reports

An initial report by CIS' Interstate Aviation Committee revealed that all three engines were operating normally, and that there was no fire or explosion before the aircraft crashed. According to the newspaper Dziennik, Polish flight recorder ATM-QAR registered that precisely at 8:41:02.5 the tail of the aircraft separated. All systems of Tu-154 stopped working at 8:41:04. Fuel temperature was below. Engines when the aircraft was above the road were at 60% of their nominal power. They also determined that the aircraft was lower than it should have been.
The discrepancy among the time of the crash registered by MARS flight recorders, ATM-QAR recorder, and when electricity lines were cut by the crashing aircraft a second or two before the final crash was never explained.
On 19 May 2010, the preliminary report of the investigation into the crash was published. Alexei Morozov, the head of the technical commission of Russia's Interstate Aviation Committee, stated that the Tupolev Tu-154M had no mechanical faults, and that an air traffic control official at Smolensk North Airport had "warned twice that visibility was 400 metres and that were no conditions for landing". The investigation ruled out a terrorist attack, explosion or fire on board the aircraft as the cause of the crash. It was also reported that the voices of two non-crew members were heard in the cockpit during the period leading up to the crash. One of the voices was identified by sources as the Polish Air Force Commander, Lieutenant General Andrzej Błasik. However, according to the findings of the Polish prosecutor's office in January 2013, General Błasik had not stayed in the cockpit and was a regular passenger. The other voice was later identified as the Director of Protocol.
According to the Interstate Aviation Committee report from 19 May 2010, the aircraft first hit an tree approximately from the runway. The aircraft was also off by from the extended middle line of the runway. The TAWS alarm "Pull up!" was first sounded at altitude and then repeated several times before the crash. It was first sounded 18 seconds before hitting the tree and the crew attempted to abort landing 13 seconds later. Due to geographical relief the aircraft was actually below the runway at the time of the first impact.
On 26 May 2010, it was reported that pilot error had been identified as the reason for the crash. Edmund Klich, the head of the Polish investigative commission, stated in an interview "Pretty much everything is clear right now and nearly all evidence has been gathered". "The pilots ignored the plane's automatic warnings and attempted an incredibly risky landing," Klich said. According to the report, the crew of the Tupolev Tu-154M failed to respond for 13 seconds when the plane's "terrain approaching" alarm warned that the aircraft was less than from the ground. The aircraft attempted to pull up after hitting a birch tree, but part of the left wing had been sheared off in the impact. The aircraft then went into a roll before landing on its back and disintegrating five seconds later. Edmund Klich declined to speculate on whether the pilot had been placed under pressure to land, commenting, "Psychologists will have to assess the stress levels the pilots were subjected to."
On 1 June 2010, Poland's Interior Ministry published a transcript from the cockpit voice recorder of the crashed Tu-154M. The transcript confirmed earlier reports that the aircraft had attempted to land in bad weather against the advice of air traffic control and the plane's terrain awareness warning system. At one point in the recording, Mariusz Kazana, the Director of Diplomatic Protocol in the Ministry of Foreign Affairs, enters the cockpit and was told by the pilot "Sir, the fog is increasing. At the moment, under these conditions that we have now, we will not manage to land" to which Kazana replies "Well, then we have a problem."
Expert commentators have noted that the flight navigator, who was listing the altitude readings on the transcript, was referring to the radar altimeter rather than the pressure altimeter. Because the terrain rises up to the runway, this could have had the effect of causing the pilot to fly far too low. The Final Report confirms this is exactly what happened.
The Russian report was published on 12 January 2011, and the Polish report was published on 29 July 2011. Both reports placed the majority of the blame for the accident on the pilots for descending too low without being able to see the ground. The Polish report also placed harsh criticism on the organization of Poland's special aviation regiment and its leaders, as well as finding deficiencies in the performance of the Russian air traffic controllers and in the airport's lighting and approach area. In Polish discourse, there remained wider questions and unease about the potential causes of the crash. This prompted a Warsaw court and a separate military investigation. Some of the unease subsequently fueled conspiracy theories revolving around aspects of the investigation, such as Russia's decision not to return the Polish plane wreckage to Poland. In the aftermath of the accident, Russia published a large number of restricted documents on the Katyn massacre, and declassified and published many more. Additionally, the Russian State Duma issued a declaration blaming Soviet leader Joseph Stalin and other leaders for ordering the Katyn massacre. Subsequent Katyn memorials have been joint Russian/Polish affairs attended by the leaders of both countries.

Russian final accident report

The MAK completed their investigation on 20 October 2010. A copy of the report was sent to the Polish authorities, who had 60 days to comment, after which the report was published on 12 January 2011.
After the Interstate Aviation Committee report's publication, Poland stated that it was created in violation of Annex 13 to the Convention on International Civil Aviation because some requested documents or evidences were not provided by Russia and, according to a Polish lawyer, because Polish comments to the final report were not agreed to nor fully applied.
The final report noticed that the captain's electronic altimeter was set higher than the actual position. This change was made after the aircraft began its final approach and soon after the first TAWS warning sounded. All other altimeters on board were set correctly. The investigation also determined that the controller's radar screen was not calibrated correctly and showed the airplane as being closer to the runway than it actually was. Additionally, his radio calls to the crew regarding their distance to the runway were given in advance by an average of.
As part of their investigation, MAK conducted an experiment in a Tu-154M simulator to determine how late the crew could have gone around. "The experiment confirmed that during approaches in conditions similar to the flight conditions of the T-154M... with a similar flight profile with vertical speed of descent of 7–8 m/s... the aircraft characteristics guaranteed safe go around from the height of 40 m." Taking into consideration the terrain at Smolensk, the investigation determined the last moment a go-around maneuver would have been successful was coincident with the first officer calling "Go around" and briefly pulling the control column at.

Polish comments on the draft of the final report

On the same day that the final report was published by MAK, Poland published its comments on the draft of the final report sent to MAK before. Poland stated that their comments were not taken into consideration. MAK did not include them in the report, but published this document on its website among other appendixes. Poland also published a final version of MAK report with changes performed by MAK in reaction for Polish comments highlighted.
The main points of Polish comments are:
At an 18 January 2011 press conference, the Polish investigation made public the information contained in ATC recordings, and their analysis of such. They concluded that the "on course, on glide path" calls given to the pilots were made when the aircraft was actually off course, and furthermore the "Level!" call was given 11 seconds too late.

MAK publication of ATC tapes

In response to the Polish claims of publicity MAK published transcripts of ATC recordings on its website. The announcement made on MAK website states that the transcripts are based on a copy of recordings identical to the one which was given to the Polish side during the investigation.
The transcripts include: "Open microphone", phone calls and radio transmissions. The transcripts show that communication between the ATC and PLF101 was done mostly in Russian with only a few English phrases.

Causes

MAK report

The MAK report found the "immediate cause" of the accident was the failure of the crew to make a timely decision to proceed to an alternate airport despite being warned multiple times of the poor weather conditions at Smolensk. Another immediate cause was the descent below minimums without visual contact with the ground as well as ignoring numerous TAWS warnings. This led to controlled flight into terrain. Additionally, the MAK report found an "immediate cause" of the accident was the presence in the cockpit of the Commander-in-Chief of the Polish Air Force, which placed extreme stress and "psychological pressure" on the Captain to "continue descent in conditions of unjustified risk with a dominating aim of landing at any means."
A "contributing factor" to the accident was a long discussion with the Protocol director and the crew of the Yak-40 regarding the actual weather and the impossibility of landing at Smolensk in such weather conditions. The report found this discussion caused the Captain to experience "clash of motives." On one hand he knew that landing in the reported weather conditions was unsafe. On the other hand, he faced strong motivation to land at Smolensk anyway. He expected a strong negative reaction from the President if he chose to divert the airplane and land at an alternate airport.
Other "contributing factors" were a lack of compliance with standard operating procedures, a lack of crew resource management, and a significant gap in bad weather flights by the PIC. Additional "contributing factors" were the Navigator calling out radar altitudes without considering the uneven terrain in the area, utilization of the autopilot and autothrottles much lower than minimum descent altitude which did not comply with the Flight Crew Operations Manual for the Tu-154, and the late start of the final descent which caused the crew to maintain a higher than normal vertical speed.
A "systemic cause" of the accident were "significant shortcomings in the organization of flight operations, flight crew preparation and arrangement of the VIP flight in the special air regiment."

Official Polish government report

The Polish Committee for Investigation of National Aviation Accidents published its report on 29 July 2011, also available in English and Russian. While the report stated that pilot error was the main cause of the accident, with the crew lacking adequate training in operating in adverse weather conditions, it differed from the Russian report in several aspects.
Chief among these differences was a conclusion that the pilots were not placed under pressure forcing them to land at Smolensk, and furthermore the crew did not want to land and after reaching 100m altitude and had decided to go around using the autopilot. However, it was impossible for the autopilot installed in the aircraft to conduct an automatic go-around from a non-precision approach. The Polish investigation concluded this caused a delay in executing the go-around which contributed to the crash.
Another major difference was a conclusion that Russian air traffic control played a part in the accident by passing incorrect information to the crew regarding the plane's position. ATC gave distance callouts on average in advance, and told the aircraft it was on the correct glidepath when it actually was not. Furthermore, the controllers gave the "Level 101" command ten seconds after the aircraft passed the altitude where such call was supposed to be given.
The Polish report also found three deficiencies regarding the Smolensk airport which contributed to the crash. One was a large number of obstacles in the area before the runway which should have been removed to keep the protected approach airspace clear of obstructions. The second deficiency was with the approach lighting system, which was charted incorrectly and not well maintained. Many bulbs were burned out, several others were missing their lenses, and others were obscured by shrubbery. The third concern was with the airport information received by Poland, which contained incorrect information. In addition to the lighting system not being depicted correctly, the airport's location was charted approximately to the North of its actual position.
Due to numerous accusations raised by Law and Justice opposition party who rejected the official report's conclusions, a new commission was created in 2013, headed by Maciej Lasek. Its task was to publish and explain all the technical evidence used in the official report. Lasek commission's produced over a hundred very detailed technical reports, maps, transcripts, photos and videos which were originally published on www.faktysmolensk.gov.pl website. Shortly after the 2015 Polish parliamentary elections the website was shut down and all documents removed by the new government, but were subsequently restored on an independent mirror.
Cause of accident according to Polish report:
Circumstances contributing to the accident:
  1. Failure to monitor altitude by means of a pressure altimeter during a non-precision approach;
  2. failure by the crew to respond to the PULL UP warning generated by the TAWS;
  3. attempt to execute the go-around maneuver under the control of ABSU ;
  4. Approach Control confirming to the crew the correct position of the airplane in relation to the RWY threshold, glide slope, and course which might have affirmed the crew's belief that the approach was proceeding correctly although the airplane was actually outside the permissible deviation margin;
  5. failure by LZC to inform the crew about descending below the glide slope and delayed issuance of the level-out command;
  6. incorrect training of the Tu-154M flight crews in the 36 Regiment.
Conducive circumstances:
  1. incorrect coordination of the crew's work, which placed an excessive burden on the aircraft commander in the final phase of the flight;
  2. insufficient flight preparation of the crew;
  3. the crew's insufficient knowledge of the airplane's systems and their limitations;
  4. inadequate cross-monitoring among the crew members and failure to respond to the mistakes committed;
  5. crew composition inadequate for the task;
  6. ineffective immediate supervision of the 36 Regiment's flight training process by the Air Force Command;
  7. failure by the 36 Regiment to develop procedures governing the crew's actions in the event of:
  8. * failure to meet the established approach criteria;
  9. * using radio altimeter for establishing alarm altitude values for various types of approach;
  10. * distribution of duties in a multi-crew flight.
  11. sporadic performance of flight support duties by LZC over the last 12 months, in particular under difficult WC, and lack of practical experience as LZC at the SMOLENSK NORTH airfield.

    Notable passengers

In addition to Kaczyński and his wife Maria, and Ryszard Kaczorowski, the former last President of Poland in exile, on board were the military chiefs of staff, the national bank governor, a deputy foreign minister, head army chaplains of the Catholic and Orthodox churches, head of the National Security Bureau, three deputy parliament speakers, Olympic Committee head, the civil rights commissioner Janusz Kochanowski, trade union activist Anna Walentynowicz, and at least two presidential aides and widely known national lawmakers.

Political aftermath

In accordance with the Polish Constitution, on the President's death his duties were taken on by the Marshal of the Sejm —at the time Bronisław Komorowski, who thus became Acting President of Poland. Within two weeks he was obliged to announce the date of the popular presidential election, to be held within a further 60 days on a weekend. Kaczyński was up for re-election in late September or early October, before the end of his first five-year term.
Despite the deaths of the president and numerous officials, the crash was not expected to impair the functions of the Polish government, since no cabinet ministers were aboard the plane. The Polish Armed Forces were dealt a severe blow, however, since all of their senior commanding officers were killed; their duties were automatically taken over by respective deputy commanders, following standard contingency plans for such a situation.
The commemoration of the 70th anniversary of the Katyn massacre was split up because of the political conflict between the liberal-conservative government of Prime Minister Donald Tusk and national-conservative President Kaczyński.
On 7 April, Tusk, along with government officials and members of his Civic Platform party, went to Katyn
on invitation from the Prime Minister of Russia, Vladimir Putin.
The official commemoration, organised by Polish Council for the Protection of Struggle and Martyrdom Sites, was scheduled on 10 April. Nevertheless, both ruling coalition and opposition were represented on the plane, with six and nine members of the Sejm, as well as one and two from the Senate, respectively, some of them well known in Poland. Many passengers were actively opposed to Tusk's policies, including:
The President of the Association of Former Intelligence Officers and former CIA analyst, S. Eugene Poteat, has written that political violence should not be ruled out under the circumstances of the aircraft crash.
The Marshal of the Sejm, Bronisław Komorowski, had previously been announced as the Civic Platform's candidate in the presidential election.
He suggested that the date of the elections should be decided by the parliamentary opposition, with him acting merely to guarantee that the Constitution is respected.
On 17 April, one week after the crash, a memorial service, including a two-minute silence, was held to honour the victims of the crash. It was reported that over 100,000 mourners attended the event, held in Piłsudski Square; however, up to 1.5 million had been expected.

State funeral

The funeral service for the presidential couple took place in Saint Mary's Basilica in Kraków on 18 April. The couple were buried in a crypt below Wawel Cathedral, a place traditionally reserved for people considered to be heroes of Polish history.

Presidential election

The first round of the election to elect President Kaczyński's successor was held on 20 June 2010. Since no candidate obtained an absolute majority, a run-off was held on 4 July 2010, between the two highest-polling candidates: the acting president Bronisław Komorowski, and the late president's brother Jarosław Kaczyński. While commentators noted that PiS gained some sympathy votes, it was not seen as a decisive factor in the election. In the second round of the election, Komorowski defeated Kaczyński with 53% of the vote.

VIP flight reorganisation

Following the publication of the Polish Accident report, the 36th Special Aviation Regiment which operated the flight was disbanded, and 13 Polish military officers were dismissed. Most Polish officials were instructed to fly on regular civilian flights. Two Embraer 170s were retained for government VIPs, but were flown by civilian pilots and operated by LOT Polish Airlines. The remaining aircraft from the regiment, including the surviving Tu-154, were sold.

Reactions

Poland

In Poland, the public reacted with shock and grief to the disaster. Almost immediately after the news broke, tens of thousands of Poles assembled at the Presidential Palace to lay tributes, including flowers, wreaths, and candles.
A week of national mourning was declared in Poland. Poles around the world mourned Kaczyński and set up shrines in the week that followed. Many wept openly. Flags flew at half mast in Poland. Sports fixtures, including women's U-17 UEFA Championship elite qualifying phase game Poland versus Republic of Ireland in Ukraine, were postponed. Concerts were cancelled.
On 11 April, Kaczyński's body was flown to Warsaw on a military plane; tens of thousands of Poles gathered at both the airport tarmac and the streets of the city to pay their respects to the late president as his casket was driven by hearse to the Presidential Palace. Afterwards, the casket was laid in state at the Palace. The casket remained there throughout the week, until Kaczynski and his wife were laid to rest at the Wawel Cathedral a full week after the crash, on 18 April.
On 15 April, Polish scouts put a wooden cross in front of the Presidential Palace in Warsaw, at Krakowskie Przedmieście, to commemorate the victims of the crash. The establishing of the cross provoked controversy in Poland, mainly related to questions concerning the separation of church and state. Polish Catholics wanted the cross to permanently remain in front of the palace, while others, including Komorowski, wanted it moved to St. Anne's Church. After a summer of protests over the cross, it was transferred to the church on 16 September.
A public noon commemoration ceremony in Warsaw's Piłsudski Square was attended by more than 100,000 people on 17 April. Sirens sounded and bells tolled around the country. A three-gun salute was fired. People waved the flag of Poland, complete with black ribbons, as the names of the victims were read out from a white stage decorated with a giant cross and photographs of the dead. The crowds bowed their heads.

On 18 April, the couple's caskets were driven at a slow pace through the streets of Warsaw, passing the city hall and a museum dedicated to the 1944 Warsaw Uprising which Kaczyński favoured. The funeral ceremony began at 2 pm local time with a mass held at Kraków's St Mary's Basilica, with thousands attending. Archbishop of Kraków Stanisław Dziwisz presided over the ceremony, and addressed President of Russia Dmitry Medvedev personally: "The sympathy and help we have received from Russian brothers has breathed new life into a hope for closer relations and reconciliation between our two Slavic nations".
Former president Aleksander Kwaśniewski told TVN24 that, "It is a cursed place. It sends shivers down my spine. First the flower of the Second Polish Republic is murdered in the forests around Smolensk, now the elite of the Third Polish Republic die in this tragic aircraft crash when approaching Smolensk North Airport." Polish Prime Minister Donald Tusk stated that, "The contemporary world has not seen such a tragedy". Former Polish Prime Minister Leszek Miller, who had himself suffered injuries in a helicopter crash while in office, said that Poland's aircraft were known to be in need of replacement, despite the lack of evidence that anything was wrong with the particular airplane; "I once said that we will one day meet in a funeral procession, and that is when we will take the decision to replace the aircraft fleet," he said. The crash fuelled anti-Russian sentiment among far right extremists, with Polish nationalists invoking the tragedy during a riot outside the Russian embassy in Warsaw in November 2013.

Russia

and Prime Minister Vladimir Putin expressed their condolences to the acting President and speaker of the parliament, Bronislaw Komorowski. President Medvedev also announced that 12 April 2010 would be a national day of mourning in Russia. Chairman of International Committee of the State Duma Konstantin Kosachev said that "Katyn claimed yet more victims". Chairman of the State Duma Boris Gryzlov has expressed condolences.
Russians and foreigners laid flowers and candles at the Polish embassy in Moscow, and at the Polish consulates-general in Saint Petersburg and Kaliningrad.
After the aircraft crash, the state owned Russia Channel broadcast the film Katyń for the second time in Russia. The film, which was not distributed in Russia, was first shown in Russia on another state-owned channel, the less popular Kultura Channel on 2 April 2010. The first showing of Katyń was a political event, which was followed by a serious discussion of Polish-Russian relations by politicians and public figures, and drew high audience numbers for the smaller channel, with an estimated 100 million Russian viewers.
While Polish commentators saw Putin's participation in the ceremony held on 7 April as a symbolic gesture, they were touched when Putin and Tusk paid tribute and laid flowers at the site of the crash. Tusk knelt and briefly hid his face in his hands, then stood up as Putin patted him on the shoulder. The two hugged, then gave a joint press conference on the investigation into the crash. Polish commentators noted this was a human gesture, and a display of emotion that Poles had longed to see from their eastern neighbours.
On 11 April, holding a bouquet of red roses, Putin was reported to have appeared truly distressed as he escorted Kaczyński's body to a Warsaw-bound plane. Later Putin said in a Polish television interview: "This is of course first and foremost Poland's tragedy and that of the Polish people, but it is also our tragedy. We mourn with you".
The Russian response has been noted favourably by Poles, with talk of a thawing in the relationship between Russia and Poland. Witold Waszczykowski, deputy head of Poland's National Security Bureau, told Reuters, "We did not expect this gentle, kind approach, this personal involvement from Putin. Naturally it will have a positive impact on the relationship between our countries." Jerzy Bahr, the Polish ambassador to Russia also stated, "We can sense Russian solidarity at every step of the way."
As part of this thawing of relations, on 28 April 18 days after the crash, Russia's state Archive publicly published a number of previously secret files on the Katyn massacre on their website. The files were declassified in the early 1990s, but before their publication they were only available to specialized researchers.
The strongest admission was yet to come. On 26 November 2010, the Russian State Duma passed a resolution admitting that Soviet leader Joseph Stalin personally approved the Katyn massacre. The Soviets had long claimed Nazi Germany were the ones responsible. Although this stance changed in 1990 when Mikhail Gorbachev admitted the Soviet NKVD secret police carried out the massacre, the November 2010 resolution was the first time the Russian government admitted direct involvement by Stalin.
In an interview with Rzeczpospolita, Andrei Illarionov, Vladimir Putin's former advisor, noted, "... contrary to the promises, the investigation of this crash is neither transparent nor dynamic." and added, "... the Polish side does not have full and free access to documents and evidence." Illarionov was also one of the signatories of an open letter written by Russian dissidents, which voiced concerns about the conduct of the investigation. According to the letter, "rapprochement with the current Russian authorities is more important for the Polish government than determining the truth about the plane crash." Polish Prime Minister Donald Tusk responded that his government would obtain flight data from the Russian investigators before making its own judgment and revealing it to the public.

International

At least 96 countries, 13 international organizations and several other entities expressed their reaction on behalf of the incident. An official mourning was proclaimed in 18 countries other than Poland. Condolence books were opened in many public locations such as the Polish centre in Hammersmith, where Prince Charles signed their condolence book.
Twenty-three countries observed a varying number of days of official mourning; Brazil: 3, Bulgaria: 1, Canada: 1, Cape Verde: 1, Croatia: 1, Czech Republic: 2, Estonia: 1, Germany: 1, Georgia: 1, Hungary: 1, Latvia: 1, Lithuania: 4, Maldives: 2, Moldova: 1, Montenegro: 1, Poland: 9, Romania: 1, Russia: 1, Serbia: 1, Slovakia: 1, Spain: 1, Turkey: 1, Ukraine: 1.
Victims of the airplane crash were also commemorated by minute of silence before several football matches throughout Europe, including El Clásico Real Madrid C.F. – FC Barcelona in Spain; or FC Baník Ostrava – 1. FC Slovácko and Prague derby AC Sparta Prague – SK Slavia Praha in the Czech Republic.
Some concern arose that Kaczyński's funeral would have to be delayed as a consequence of volcanic ash emanating from Iceland and the resulting air travel disruption in Europe. Only one airport in the country was open, and several international dignitaries were unable to attend. The funeral nonetheless went ahead as scheduled.
NATO was reportedly concerned over the possible compromise of many of its secret codes and communications procedures to the Russian government. Many of the Polish government and military officials on the aircraft apparently carried secret NATO communication key codes and devices which were recovered by the Russians after the crash.
In 2018 PACE issued resolution #2246 which calls Russian Federation to hand over the wreckage of the plane.

Polish parliamentary committee investigation

In July 2010, a group of Polish MPs, mostly from the Law and Justice party, formed the "Parliamentary Committee for the investigation of the Tu-154M crash in Smolensk", chaired by the party's deputy leader Antoni Macierewicz. Later in November, Macierewicz called for the United States to lead an independent international commission on the accident. Some US Republican congressmen supported this idea but the U.S. has never acted upon it. In March 2015 the Polish committee published a report in which it claimed that two separate explosions took place on board the Tupolev in the last few seconds of its flight, bringing the aircraft down; a third explosion allegedly occurred after the impact with the ground.
The committee's conclusions were partly based on a paper by Dr. Wiesław Binienda of the University of Akron, in which the author presented computer simulations that claimed to prove that the impact with the birch tree could not have severed the plane's wing. The paper, however, was self-published and not peer-reviewed. According to group's scientists – Binienda, Kazimierz Nowaczyk from the University of Maryland and Gregory Szuladziński – the direct cause of the crash was not a collision with an obstacle, but two explosions in the last phase of the flight: first on the left, by which the plane lost part of the left wing, then another inside the hull. Alleged contradictions, errors and manipulations in the official reports has been pointed out. Binienda also claimed that the cut wingtip couldn't fly over 100 m from the tree, the hull couldn't be torn to the outside by a collision with the ground, there should be a crater in the ground as a result of the crash if the plane wasn't torn in the air before. Szuladzinski's report stated that: any landing in a wooded area, no matter how adverse, and at what angle, could not in any way result in such fragmentation, which has been documented. Nowaczyk analyzed data from FMS and TAWS system and came to the conclusions that the plane flew over the tree and was torn at a height over 30 m above the ground. Wacław Berczyński, constructor of Boeing pointed to the pulled out rivets of the sheeting and claimed that it could be caused only by an internal explosion.
Every year since October 2012, an independent Smolensk Conference was organised in Warsaw and was attended by scientists and researchers from Polish and foreign universities to provide a forum intended to introduce and discuss independent studies related to the catastrophe. The last of these meetings was convened in November 2015 and its proceedings were published in 2016. The Scientific Committee of the Conferences was chaired by Professor Kazimierz Flaga. The Advisory Committee included 114 academics.
, Russia is still in possession of the wreckage and black boxes of the Tupolev, having refused various requests made by the Polish government to return the items.

Claims of explosives traces

On 30 October 2012, Polish magazine Rzeczpospolita reported that traces of explosives had been detected by investigators in the wreckage of the Tupolev, on the wings and in the cabin. The claims were denied by Polish prosecutors—who pointed out that a number of common substances could as well have produced the observed readings—and were later withdrawn by the magazine itself. Rzeczpospolita's editor-in-chief and three other staff, including the reporter of the initial claim, resigned from their jobs. The author of the article in question, Cezary Gmyz, maintained that what he wrote was confirmed by four independent sources. In November 2015, a court in Poland ruled in favour of the sacked journalists, stating that the information published in the article correctly reflected the state of knowledge at the time of publication.
In 2017, it was announced that the British Ministry of Defence was engaged by the Polish Government to examine the wreckage of the aircraft for traces of explosives. The work will be done by scientists based at the Forensic Explosives Laboratory at Fort Halstead, Kent., no results from the analysis were published.

New Polish investigation

Following Law and Justice's victory at the 2015 Polish parliamentary elections, the new conservative government appointed the chair of the Polish Parliamentary Committee of Investigation, Antoni Macierewicz, as defence minister, and the question of the Smolensk crash was brought back into the government's agenda. New foreign minister Witold Waszczykowski announced that Poland would sue Russia in a human rights court over Moscow's withholding of the wreckage. The Consul of Europe's Parliamentary Assembly designated a special investigation rapporteur who will carry out an inquiry on whether holding back the wreckage and other evidence material by the Russians is justified.
On 25 November 2015, government spokeswoman Elżbieta Witek called for former Prime Minister Donald Tusk to be put on trial for his handling of the 2010 air disaster. Adam Lipiński, from the Prime Minister's Chancellery, accused Tusk of negligence and weakness in handling the investigation and the restitution of the wreckage.
Deputy Minister of Culture Jarosław Sellin stated his absolute conviction that there were explosions on board the Tupolev and that the real causes of the presidential plane crash has not yet been established.
In November 2015, the government shut down the faktysmolensk.gov.pl website, which had been set up by state authorities under Tusk's cabinet to explain in simple terms the findings of the official investigations. No reason was given for the website closure. An independent mirror was created shortly after.
Polish President Andrzej Duda, from the Law and Justice party, wrote a letter to the participants of the 4th Smolensk Conference that took place on 14 November 2015 in Warsaw, describing the official Russian and Polish accident reports as 'simply hypotheses' in contrast with evidence, and stating that the investigation on the crash is not complete.
In February 2016, Macierewicz announced the official reopening of the investigation, declaring that the previous inquiries were "riddled with mistakes" and reaffirming his belief that the aircraft disintegrated mid-air immediately before impacting the ground.
As part of the renewed investigation, the remains of the deceased Polish president were exhumed on 14 November 2016.
In January 2018, the Polish government subcommittee re-investigating the accident claimed that a number of explosions had occurred aboard the airliner. In February 2018, the commission presented their preliminary findings, repeating the earlier claims. The head of the previous commission, Maciej Lasek, dismissed the claims as "illusions" and "propaganda". In April 2018, the commission headed by Antoni Macierewicz published a report which said that the plane was destroyed in the air by an explosion, and that Russian air traffic controllers at the Smolensk air base had misled the pilots about the plane's location during its approach to the runway.

Conspiracy theories

Soon after the crash, Artur Górski, a Polish MP from the Law and Justice party, claimed that the Smolensk air traffic controllers were ordered to prevent the plane from landing, so that the president could not attend the Katyń ceremony, resulting in the crash. Górski later apologized for his remarks.
Conspiracy theories have been in circulation since the day of the accident, claiming in general that the crash was in fact a political assassination, an act of war against Poland or an elaborate coup attempt, possibly orchestrated by Russia. The range of such theories has been described by some international media as "dizzying"; from the idea that the fog around the airport had been artificially produced, to victims' bodies being doctored in fake autopsies, to the idea that explosives were planted on board the plane.
Law and Justice's leader Jarosław Kaczyński and the head of the parliamentary committee of investigation Antoni Macierewicz have been described as long time supporters of the assassination theory, and have repeatedly accused the then prime minister Donald Tusk of being involved in a cover-up. Macierewicz repeated these accusations as newly appointed minister of defence in 2016, causing a significant controversy in Polish, Russian and international media.
Opinion polls in 2012 and 2013 found that one-third of Poles think it is possible that the Smolensk crash was an assassination.
All of the evidence allegedly supporting alternative theories is discussed in the 2013 report of Maciej Lasek commission. For example, the bomb explosion theory is not supported by the fact that the plane's debris are concentrated in a relatively small 160x50 m area, and no parts of the plane's interior were found before the first ground contact. However, the bomb theory does have some support: British air accident investigator Frank Taylor, who was involved in the investigation into the losses of Pan Am Flight 103 and British Airtours Flight 28M, challenged the official report. He claimed that the Russian authorities came up with their theory that the aircraft collided with the tree, and then made the evidence fit that theory. He claimed that there were explosions on board the aircraft, including in its wing, immediately before it reached the tree. Russia dismissed his claims.

In popular culture

The National Geographic TV series Mayday dramatized the accident in a 2013 episode titled Death of the President.

Smolensk disaster in film, theater, music and literature