Having read the preliminary ATSB Report, I wonder if I'm the only one still puzzled by the root cause of the engine failure. They say on page 16 that a "recent key finding" was the fatigue crack associated with a "mis-aligned area of counter-boring" in the stub pipe. Yet they don't seem to conclude that this manufacturing error was indeed the cause?
And if it was, then what about the earlier ADs issued; do we now assume that at that stage they were issued as catch-alls, more in hope than expectation?