Smolensk air disaster

On 10 April 2010, a Tupolev Tu-154 aircraft operating as Polish Air Force Flight PLF 101, crashed near the Russian city of Smolensk, killing all 96 people on board. Among the victims were the president of Poland, Lech Kaczyński, and a number of senior Polish military officers, Polish government officials, and members of the Polish clergy, as well as relatives of victims of the Katyn massacre. The group was arriving from Warsaw to attend an event commemorating the 70th anniversary of the massacre.

The pilots were attempting to land at Smolensk North Airport in fog, with visibility reduced to about 400 m. 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 organisation and training of the Air Force unit involved, which was subsequently disbanded. Several high-ranking members of the Polish military resigned following pressure from politicians and the media.

Various conspiracy theories have been circulated alleging that the plane had been deliberately brought down by the Russians in an act of political assassination, and that the 2011 investigations constituted a cover-up and that the Polish government of the time — primarily controlled by the Civic Platform party as opposed to Lech Kaczyński's Law and Justice party (PiS) — was complicit in or aware of the plot, or at least aided in the efforts to cover it up. These conspiracy theories are regularly promoted by PiS, particularly by party leader Jarosław Kaczyński (twin brother of Lech Kaczyński) and deputy party leader Antoni Macierewicz. Following PiS's return to government, a new investigation was opened into the disaster, chaired by Macierewicz; its 2022 conclusion alleged a Russian plot. The new report did not produce any evidence that could conclusively challenge the findings of the 2011 reports, was later indicated to have been the subject of tampered evidence, and was revoked in December 2023.

Background

The flight 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 19 km west of Smolensk.

Smolensk North 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 (ILS), the standard system used in most developed countries. The Polish Tu-154 was modified to use a Western-style ILS. A non-directional beacon (NDB) was installed at the airport, but such a device 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 (approach minimums) were cloud base 100 m and visibility 1000 m. 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%. 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 obscured 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 (900 m) had their light filters shattered and, of three bulbs installed, only one was serviceable.

The aircraft used the callsign Polish Airforce 101, operating flight PLF101. PLF is the ICAO three-letter designator for the Polish Air Force, used to identify the operator of an aircraft by air traffic control. The aircraft was a Tupolev Tu-154M of the 36th Special Aviation Regiment of the Polish Air Force (Siły Powietrzne), 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 (whichever comes first). 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. 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 cockpit crew of Flight 101 consisted of pilot Captain Arkadiusz Protasiuk, 36, co-pilot Major Robert Grzywna, 36, navigator Lieutenant Artur Ziętek, 32, 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 flight hours, all on the Tu-154.

Flight recorders

Two flight recorders, the cockpit voice recorder (CVR) and the flight data recorder (FDR), 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 (QAR) designed for maintenance diagnostics, was found on 12 April. The two Flight Management System (FMS) 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 synchronising 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.