What happened
On July 24, Flight SU1912 was operating a multi-leg journey from Odessa Airport, Ukraine, with scheduled stops in Kiev, Chelyabinsk, Novosibirsk, Irkutsk, and Khabarovsk. During the morning approach to Irkutsk-Intl Airport, the flight crew encountered adverse weather characterized by rain and low cloud cover. Due to restricted visibility, the crew struggled to identify the runway and required assistance from Air Traffic Control during the final approach phase.
As the aircraft descended, it became unstable. ATC directed the pilot to execute a right turn to intercept the glide path because the plane was descending to the left. The aircraft approached the runway at an excessive vertical rate and at a speed 32 km/h slower than the required parameters. Upon touchdown, the right main gear hit the runway 154 meters past the threshold, followed by the left main gear 183 meters from the threshold. The force of this impact exceeded the aircraft's structural certification limits.
Following the landing, the aircraft veered left from the centerline and lost its left wing. The plane traveled 500 meters off the main runway before catching fire. The accident resulted in 97 fatalities, including four crew members, and 29 injuries. The Sukhoi Superjet 100 (implied by context of SU flight numbers/type) was destroyed.
Findings
Investigations into the crash revealed that one flight data recorder was non-functional due to inadequate technical oversight, while the second recorder disconnected during the initial gear impact. The primary factor in the accident was the aircraft's low approach speed and high vertical descent rate, which led to a violent impact with the runway surface.
Data indicated that the combination of crew errors and incorrect speed indications likely caused the loss of airspeed on short final. It is suspected that a power system leak may have occurred at a low altitude, contributing to the erroneous speed readings during the period of marginal weather conditions.