Might be well wide of the mark with regards whether or not it was these particular airframes but it would appear that these are used by aggressor units.....
The United States has bought two
Su-27 Flanker fighter jets to help train U.S. pilots to cope with the growing number of Russian 4th-generation aircraft sold around the globe, a U.S. online magazine said. The two planes have been bought from a private Ukrainian company by the Reno-based Tac Air, which provides training and test support for the military.
The aircraft will also be used to test the effectiveness of new U.S. radars and electronic warfare equipment, the Strategy Page reported.
The 33-ton
Su-27 is similar to the U.S. F-15, but costs some 30% less, the source said.
Su-27 fighters have been produced in Russia since 1982. They are still widely used in the Russian Air Force and are gradually undergoing maintenance repairs to extend their service life.
The Su-27 Flanker and its variant, the Su-30 Flanker C, account for a major share of Russia's arms exports. In the past, Russia's Sukhoi aircraft maker sold Su-27 and Su-30 fighters to China, India, Malaysia, Venezuela and Algeria.
In 2007, Sukhoi exported 50 of these aircraft, accounting for 50% of Rosoboronexport's export revenues.
According to U.S. sources, the two aircraft, which have been acquired in a commercial variant, stripped of weaponry, are being overhauled and modified by the U.S. Pride Air company.