About Saratov Airlines flight 703:

The flight was a regularly scheduled domestic passenger service from Moscow's Domodedovo Airport to Orsk Airport in Orsk, a city near the border to Kazakhstan, operated by Russian regional carrier Saratov Airlines. The scheduled departure time from Moscow was 14:00.[1] Flight 703 took off from Moscow at around 14:21.[2][3]

Several minutes after taking off from Moscow, the aircraft's speed and altitude started to fluctuate. Moments before the crash, Flight 703 had gained an altitude of 1,800 metres (5,900 ft) and an airspeed of 600 kilometres per hour (320 kn; 370 mph). It then lost altitude rapidly until it disappeared from the radar at an altitude of around 900 metres (3,000 ft).[1]

The aircraft crashed near the villages of Argunovo and Stepanovskoye [ru] in Ramensky District of Moscow Oblast.[4] The accident occurred at 14:27 local time (11:27 UTC), six minutes after take-off from Moscow's Domodedovo Airport.[2][5] According to a source inside the investigation, a few minutes before the crash the pilot of the aircraft told air traffic controllers about a malfunction, and that he planned to make an emergency landing at Zhukovsky. This report was later dismissed by the investigation committee.[6] Eyewitnesses reported that the aircraft was in flames during its descent to ground.[7] The crash was caught by a surveillance camera in a nearby house. The footage showed that the aircraft slammed into the ground, and immediately burst into flames.[8]

The Russian prosecutor's office launched criminal proceedings for suspected violations of air traffic safety rules. It found reports that the airline had been banned from operating international routes in 2015, and that these had resumed after a change in policy in 2016. The Russian Federal Service for Supervision of Transport (Rostransnadzor) stated that during its examination on the accident aircraft, the airline had violated the procedure for changing oil in the gearboxes, and the procedure for washing the air starter filter.

Investigation:

The Russian Interstate Aviation Committee (IAC) opened an investigation into the accident.[20] President Vladimir Putin also set up a special commission to investigate the crash. Within the first few hours of the investigation, the Ministry of Transport announced two theories regarding the crash – weather conditions and human factors.[13]

The wreckage of Flight 703 was scattered over a wide area. Officials stated that the radius of the crash site area was about one kilometer (0.62 miles), which added suspicion that the aircraft possibly had disintegrated in mid-flight. Since a witness stated it was in flames during its descent, a bomb theory was put forward by several investigators.[8] Both flight recorders (the flight data recorder and the cockpit voice recorder) were found on 12 February.[21][22]

Saratov Airlines' documents related to the aircraft were impounded as part of the routine investigation. The crash has also caused the Russian Emergency Ministry to discuss whether all Antonov An-148s should be grounded temporarily. Personnel at Moscow Domodedovo Airport were also interviewed.[23]

Russian news agency Rambler News Service (RNS) reported that the pilot of Flight 703 had declined to have the aircraft de-iced before the departure.[24] According to a METAR weather report, the weather at 11:00 included snow showers and a temperature of -5 °C (23 °F) at Domodedovo Airport.[25]

On 13 February, the IAC reported that initial analysis of data from the flight data recorder showed that the pitot tube heaters were not turned on and there were discrepancies in the airspeeds being displayed to the pilots, with one airspeed indicator showing increasing airspeed, one showing decreasing airspeed and the third showing no airspeed. The data also showed that the aircraft was under manual control when it pitched nose down some 30° below the horizontal and remained in that attitude until it impacted the ground.[25] The first officer tried to stop the sharp descent, but failed to persuade the captain that the plane was out of control.[17]

On 27 June 2019, the IAC reported that the crash, during climb in instrument meteorological conditions, was caused by the crew's erroneous reactions to unreliable airspeed indications caused by ice blockages of all three pitot probes, which led to the loss of control of the aircraft's flight dynamics resulting in a dive and collision with the ground.