A group of Russian air inspectors will make an aerial observation flight over the territory of the United States in line with the Open Skies Treaty, Russia\'s Defense Ministry said on Saturday. It would be the 20th observation flight of the Russian inspectors in the states, members of the Open Skies Treaty in 2011. \"The Tupolev Tu-154M Lk-1 aircraft with a group of Russian inspectors on board will make an observation flight over the territory of the United States under the international Open Skies Treaty from July 31 to August 8,\" the ministry said in a statement. According to the ministry, the Russian aircraft will take off from the Travis Air Force Base, located in California, while the maximum range of the flight will total 4,250 kilometers. The ministry added that both the Russian and the U.S. inspectors would be on board and would control the use of the equipment and surveillance systems in accordance to the existing agreements. The Open Skies Treaty, signed in 1992 at the initiative of U.S. President George H.W. Bush, established a regime of unarmed aerial observation flights over the territories of its 34 member states to promote openness and the transparency of military forces and activities. The treaty entered into force on January 1, 2002 and its regime covers the national territories (land, islands, and internal and territorial waters) of all the treaty signatory states. It is an important element of the European security structure.