Russian Air Force An-30 surveillance aircraft seen on static display during MAKS 2017 at Zhukovsky. This aircraft has been modified for "Otkrytoye nebo"or Open Skies mission to monitor military installations under the Open Skies treaty, which entered into force on 1 January 2002. On 22 November 2020, the United States withdrew from the treaty, and in December 2021, Russia formally withdrew. The An-30 for this mission were based at Kubinka.