Crew members check the equipment in the nose of an An-26 aircraft used by the Hungarian Air Force to fly observation missions under the Open Skies Treaty, July 2004. (OSCE)
Russian officers (right) greet members of a joint United Kingdom/Croatia observation flight over Russia under the Open Skies Treaty, 14 August 2006. (OSCE)
Members of a Russian crew come off their Tu-154 aircraft as they arrive in the United States, July 2000, before a flight under the Open Skies Treaty. (OSCE)
Italian crew members and their Russian counterparts pose next to a C-130H aircraft during flights over Russia, 30 September 2004, under the Open Skies Treaty. (OSCE)
Team members from Slovenia and the United Kingdom pose next to an Andover C Mk1 aircraft during a trial mission by UK over the Republic of Slovenia, at Joze Pucnik Airport, Brnik, March 2007. (OSCE)
Members of a Russian crew pose on the tarmac next to a Tu-154 aircraft together with their US counterparts during an observation flight over the territory of the United States under the open Skies Treaty, July 2000. (OSCE)
Swedish crew members pose next to their Saab-340B aircraft after an observation flight over the territory of Russia under the Open Skies Treaty, 6 April 2005. (OSCE)
Shaking hands after a joint UK-Croatia flight over Russia, 17 August 2006, under the Open Skies Treaty. Latvian representatives observed the flights. (OSCE)
Members of a joint Canadian-Swedish-Italian flight over Georgia under the Open Skies Treaty pose, 30 November 2006, next to a Canadian C-130H aircraft. (OSCE)
A camera used on a Saab-340B aircraft over Slovakia during a joint US-Swedish training flight, 28 May 2008, under the Open Skies Treaty. (OSCE/Mikhail Evstafiev)
Canadian officer A/Lt.Col. John Preston and Russian officer Col. Alexander Baryshnikov shake hands after signing a document as part of a Russian mission over Canada under the Open Skies Treaty, September 2004. (OSCE)
A group photo, including of members of the Ukrainian team participating in flights under the Open Skies Treaty, next to some of the aircraft used under the Treaty. (OSCE)
Members of a Ukrainian team that perfomed flights under the Open Skies Treaty over Turkey from 2 to 6 September 2002 pose next to their aircraft. (OSCE)
Russian and Danish military personnel responsible for a Russian flight over Denmark, July 2007, under the Open Skies Treaty, which establishes a regime of unarmed aerial observation flights. (OSCE)
Ukrainian military personnel greeted by their Czech counterparts after a flight over the Czech Republic, April 2003, under the Open Skies Treaty, which establishes a regime of unarmed aerial observation flights over the territory of its 34 signatories. (OSCE)
Czech and Spanish military experts discus a flight over Ukraine, May 2004, under the Open Skies Treaty, which establishes a regime of unarmed aerial observation flights over the entire territory of its 34 signatories. (OSCE)