Complex sentence: It was expected that in a FADEC engine runaway, engine power would become asynchronous and mismatched; yet the investigation found the engines at the crash to have matched settings, decreasing the likelihood of a FADEC malfunction being involved.
Split into simpler sentences: It was expected that in a FADEC engine runaway, engine power would become asynchronous and mismatched. The investigation found the engines at the crash to have matched settings, decreasing the likelihood of a FADEC malfunction being involved.