The East European country of Belarus is retiring its Su-27 fighters. It will probably sell them, unless it is able to find the cash to refurbish them. The Su-27s are 25 years old and were not built to fly more than 3,000 hours. This is low for modern jet fighters but typical of Russian combat aircraft. For example, last year the first 18 Su-30s India received from Russia were retired after a decade of service and a service life of only 4,000 flight hours. In many respects, the Indian made Su-30s, the Su-30MKI, is the most capable version available, due to its Israeli and European electronics and the well trained Indian pilots. The 38 ton SU-30MKI is most similar to the two seat American F-15E fighter-bomber. Even though equipped with Western electronics the aircraft cost less than $40 million each, about half what an equivalent F-15 costs. The Su-30MKI can carry more than 8 tons of bombs and hit targets over 1,500 kilometers away. But like all Russian combat aircraft, they are not designed and built to last for decades, like Western aircraft. That is slowly changing and the latest version of the original Su-27, the Su-35, is good for 6,000 flight hours.
Only about 700 Su-27s were produced (mostly between 1984, when it entered service, and the collapse of the Soviet Union in 1991), adding Su-30 production (an Su-27 updated) and you have over 1,000 aircraft (including license built ones in China and India). The MiG-29 entered Russian service in 1983. Some 1,600 MiG-29s have been produced so far, with about 900 of them exported. The 22 ton aircraft is roughly comparable to the F-16 but it depends a lot on which version of either aircraft you are talking about. Russia is making a lot of money upgrading MiG-29s. Not just adding new electronics but also making the airframe more robust.
The MiG-29 was originally rated at 2,500 total flight hours. At that time (early 80s), Russia expected MiG-29s to fly about a hundred or so hours a year. India, for example, flew them at nearly twice that rate, as did Malaysia. So now Russia is offering to spiff up the airframe so that the aircraft can fly up to 4,000 hours, with more life extension upgrades promised. This won't be easy, as the MiG-29 has a history of unreliability and premature breakdowns (both mechanical and electronic). The most recent versions of the Su-30 are built to last up to 6,000 hours.
Western warplanes are built to last longer. The F-16C was originally designed for a service life of 4,000 hours in the air. But advances in engineering, materials, and maintenance techniques have extended that to over 8,000 hours. Because of the wars in Iraq and Afghanistan, F-16s sent to these areas will fly over a thousand hours a year more than what they would fly in peacetime. The current planned refurbishment program will extend F-16C flight hours to 10,000 (10K) or more.
The U.S. Air Force will refurbish several hundred of its 22 ton F-16 fighters, because their replacement, the 31 ton F-35, is not arriving in time. Its F-16s are old, and by 2016, many will be too old to operate. The average age of existing F-16s is over 20 years, and the average aircraft has over 5,000 flight hours on it. Four years ago the first Block 40 F-16 passed 7,000 hours. Five years ago the first of the earliest model (a Block 25) F-16s passed 7,000 hours. While older F-16s and F-15s are being retired for age, they tend to have at least twice as many flight hours as their Russian counterparts.