I doubt that the Indians could have any idea of the actual costs of maintenance and so on since the design is still not fixed, nor has a single Indian variant been produced. All I know is that every design is a result of compromise and the test is whether the design objectives AS SET have been met. On this standard, the F-35 has been an abject failure. Everyone has their own set of problems, us included.
“Everyone has their own set of problems, us included.”
Yes, I didn’t say we didn’t have our problems. However, the Indian customer is not happy with the Russian designed aircraft. Why — in their opinion, it is a poor design. Is it really? I don’t know, but if it doesn’t meet its design goals for its customer, it is a problemed design.
If the design is “great” and meets its design objectives “AS SET”, maybe the Russians did a very poor job at managing customer expections for the T-50. Maybe they forgot to tell the Indians that the Mean Time Between Failure for the engines was short, while the Indians expected a longer time. Maybe they forgot to mention maintenance would cost 10x what it costs for a Su27.
Bottom line, the customer (India) is very unhappy with the design so, in their eyes, it is a poor design.