In 1955, the aircraft was reassigned to the 1st Irkutsk (134th) air transport squadron of the East Siberian Directorate of Civil Aviation.

[citation needed] After flight 11 left the Irkutsk airspace, it gradually began to deviate southward from the route.

The Irkutsk air traffic control center was staffed by Butenko, who, 21 minutes after the aircraft's departure (15:31), observed on the radar that the airliner had deviated 17 kilometers southward, but did not require the crew to return to the flight path.

Even when a bearing was received at 16:28 from the radio direction finder at Chita Airport, which, despite inaccuracies, also indicated that flight 11 was south of the route, the crew did not use this information.

Even when the pilots reported that they could not locate the non-directional beacons, could not obtain bearings, and were essentially lost, the air traffic controllers did not offer assistance.

Disoriented over the terrain, at 18:30 the crew reported to the Chita air traffic control center that they would make an emergency landing near a settlement they had spotted.

The crew was found to be partly at fault, having lost orientation and subsequently taking incorrect actions in an attempt to recover it.

Moreover, the Chita controller (Baranov) did not attempt to determine the aircraft's location during the two hours and fifteen minutes it was in his airspace, nor did he issue any commands to the crew.

The commission also noted poor internal management within the 134th Aviation Squadron, where leadership failed to adequately supervise crew operations.