The Armenian Air Force experienced a major expansion and modernization in 2004–2005. It tripled its fixed-wing combat arm through the procurement of ten surplus Su-25 from Slovakia for a total of US$1 million in August 2004. These twenty-year-old aircraft – which had not been flown for a decade and required work to re-certify their flightworthiness – were delivered in September 2005. The Su-25 receipt was also originally mis-reported as an acquisition of ten Su-27 air superiority fighters, an aircraft the Slovak Air Force never operated. Also in 2004, Armenia received a pair of L-39C trainers from each of Russia and the Ukraine, as well as two Il-76 transports from Russia in May.