On September 18, 2020, an S-2 Sintal aircraft, registration RA-0931G, was engaged in aerial chemical treatment (ACT) for sunflower fields near the settlement of Krasnoye Syundyukovo in the Ulyanovsk region. The pilot-in-command had been performing agricultural spraying operations, including five completed flights the previous day.
On the morning of the accident, the pilot performed pre-flight inspections and refueled the aircraft with chemical liquid alongside an assistant. The pilot took off at 08:00:34 to continue the field processing. The flight was conducted in Class G airspace, and no flight plans had been submitted for the current or previous day's operations.
During the climb phase, the aircraft entered a stall condition. The accident occurred while the pilot was performing a turn in close proximity to a forested area. The maneuver was executed in a direction that coincided with a strong gust of wind.
Investigation findings noted that the pilot did not undergo a pre-flight medical examination, though this was permitted under specific regulations for the landing site used. Additionally, the aircraft's design lacked specific indicators or warning devices to alert the crew to an approaching stall or critical flight regimes.