India’s Defence Minister Manohar Parrikar said in Parliament that between 2013 to 2014, the Su-30MKI suffered 35 engine failures, which is around 2.9 failures a month.
By g4sp (http://flickr.com/photos/10044448@N05/810243571) [CC BY-SA 2.0], via Wikimedia Commons
Parrikar explained that there were 69 instances of engine failure in the last four years. Thirty-three of them was because of fuel contamination, 11 were due to excessive vibration and eight was because of low pressure in the lubricant tanks.