Nothing special about engines. Rather the reverse.

There are nearly always issues that only show up with actual, real world experience. And given the complexities of engines, bound to happen.

Letely has affected obviously Pratt with the geared fan, but also the 787 Rolls engine, pretty bad too for them, and to a lesser extent the Franco-American Leap engine.

In the case of Rolls, they had become way too arrogant for their own good, so not such a big surprise. Will teach them some dose of realism.