I wouldn`t worry about failing the first time. I did exactly that, but managed to get it on the second attempt. I was one of those fortunate people to be a cadet with an airline, and 13 out of the 15 in my class failed or partialed the IRT first time.
Put it down to bad luck, and make it a god learning experience. It`ll put you in a better standing for the successful retake!!
Good luck!!