The CAF now keeps its most-ready Su-27s in Guangdong Province, the forward base for the planes while the rest of the fleet (including the damaged ones) are at a base in Anhui Province. China purchased 46 Su-27s from Russia in the early 1990s and of the 31 still operational, about 16 are thought to be combat ready at any given time. CAF Su-27 pilots typically get only 10 flight hours per month. - Adam Geibel
According to a 20 June report by Taiwanese defense sources, four Chinese Air Force Su-27 fighter planes crashed or were severely damaged during flight training over the past six months. Two of the four were damaged while their pilots were trying to land, the others crashing as a result of 'human error' (without giving further details). It is not known whether any of the pilots were killed, but these accidents bring to 15 the number of CAF Su-27s that have been taken out of service due to crashes.