I haven't seen a definitive count anywhere. It is certain that not all flights involving the MCAS problem led to a crash. The LionAir crash flight was precede

I haven't seen a definitive count anywhere. It is certain that not all flights involving the MCAS problem led to a crash. The LionAir crash flight was preceded by a flight were the pilots first experienced the MCAS problem due to the failed pitot on the plane; they disabled the trim system and completed the fight manually. It was the subsequent flight the actually crashed.