From July 31 to August 8, 2011, a Tupolev Tu-154-M Lk-1 plane with a group of Russian inspectors flew over the United States in accordance with the Treaty on Open Skies. 

The airplane departed from the Travis Air Force Base in California. The airplane’s range was 4 250 kilometers, according to a spokesman with the Russian Ministry of Defense.

Russian and American military personnel and inspectors aboard the aircraft supervised the use of the equipment and observation systems in accordance with current agreements.  

The planned flight over the United States was this year’s 20th monitoring session of Russian inspectors above the territories of nations that are signatories to the Open Skies Treaty. The Treaty was signed in 1992 in Helsinki by 35 countries of Europe and North America. The objective of the treaty is to ascertain the validity of information provided by the treaty nations relative to the location of weapons systems and troops deployment.