Some incorrect terminology is being thrown around here which is confusing things. Here is the deal, it is the same with almost every program. In the examples listed in previous posts, you are not “failing” IOE, but if you don't get it done in the prescribe time the check airman can say this person is still salvageable and may recommend extra time. This really is not that uncommon if you are coming from the CFI world flying your first jet. If you do get more then the prescribed time you get put on special tracking. All that means is that when you do finish IOE, which may just be one more trip, at the end of 6 months you will fly with a check airman who will evaluate you. Then based on how you do you either stay on special tracking or you are taken off it.

If you “fail” IOE it is something totally different, you are terminated. It does happen. I’ve heard Regionals giving some FOs 75 to 100 hours of IOE before giving up.