Complex sentence: However, Indonesian officials deny that the plane's age was a factor on the crash, as they insist that the plane was in "good condition", even though they haven't ruled out the plane's age as the cause of the crash.
Split into simpler sentences: However, Indonesian official denies that the plane's old age was a factor on the crash, as they insist that the plane was in "good condition". Even though they haven't ruled out the plane's age as the cause of the crash.