Investigators looking into the May 5 crash-landing of an Aeroflot Sukhoi Superjet revealed Wednesday that civil authorities have filed criminal charges against the pilot-in-command of the ill-fated flight. The Investigative Committee of the Russian Federation published an official statement indicating that Denis Evdokimov violated “public transport safety rules...that led to serious injuries and death...by inadvertence or negligence.” The statement further says that Evdokimov “attempted further actions on control of the aircraft that were carried out in violation of established rules and procedures” following the rough landing at Sheremetyevo Airport, resulting in the airplane disintegrating and catching fire and subsequently causing the death of 40 passengers and one crew member. Ten more people suffered injuries. The statement goes on to say, however, that the investigation remains incomplete.

The charges carry a maximum sentence of up to seven years. Before October 2, the investigator’s office called on the pilot on several occasions to serve as “a witness.” Officials continue to consider the flight’s copilot, Maxim Kuznetsov, “a victim,” along with other crew members and passengers. Evdokimov denies the charges against him and insists that the Superjet 100 developed problems with its flight controls even in the “direct law mode” after lightning struck the climbing airplane.

The civil aviation authorities looking into the crash have acknowledged that a number of onboard systems developed failures and glitches after the lightning strike. They included all onboard radios and the central computer. Even though the airplane regained some controllability, a fact that made it possible for the crew to return to the departure airport and perform touchdown, incorrect readings from various sensors and glitches in the airplane’s digital fly-by-wire controls might well have degraded handling performance to such a point that the crew could not manage a smooth landing. Whether or not the systems in question had degraded to a state that a more skilled captain could have performed better than Evdokimov stands as a key question for the court to decide.

Aeroflot top managers insist they continue to “render every support” to the investigators but called on them to exercise caution when looking into the case. “Only after a comprehensive and prudent study of all facts it might be possible to determine the real causes that led to the catastrophe and take necessary measures to avoid the repetition of similar tragic situations,” Aeroflot said in an official statement.