U.S. monitoring plane OC-135B, designed for reconnaissance missions with no weapons onboard, carried approximately 20 observers from the United States in November over the Russian territory. The goal of the mission was in line with the Open Skies Treaty, according to Ruslan Shishin, the chief of the National Threat Reduction Center.

The OC-135B plane was inspected by Russian specialists and was properly certified prior to takeoff.