I want to do some flight hours and engine life math with you.
PLAAF Su-27SK received 250 flight hours per year.
http://china-defense.blogspot.com/2009/04/decommission-of-plaafs-su-27-has.html
First contract for a batch of 24 Su-27 was signed on June 14, 1990. The original Su-27 airframe had a service life of 5000 hours. It was decommission in 2009 after 19 years of service.
5000 hours / 19 years = 263 hours per year.
I'm willing to round this down to 250 hours per year for easy calculation.
Two pilots were assigned to each aircraft, which means each pilot received 125 hours per year. But the airframe and engines received 250 hours per year. Keep in mind these hours were achieved throughout the 1990s and early 2000s when China was a much poorer country.
AL-31FN Series 3 TBO is 750 hours according to Salut.
http://www.salut.ru/ViewTopic.php?Id=2325
That means the older AL-31FN was less than that. I'm willing to be generous and give the older AL-31FN a TBO of 500 hours and service life of 1500 hours, but it could be less. The entire 1500 hour service life is used up in 6 years assuming 250 flight hours a year.
According to huitong, around 100 J-10 were produced by 2006.
Around 100 may have been produced by 2006 (01-03 batch, S/N 50x5x, 10x4x, 10x3x, 10x2x, 20x0x, 73x5x).
http://chinese-military-aviation.blogspot.com/p/fighters-ii.html
The aircraft above are over a decade old. All J-10s older than 6 years are likely to have received at least one engine replacement already.
Do you understand why I say 499 engines isn't enough? Can anyone prove China purchased more than 499 AL-31FN from Russia? Give me proof.
