my job requires a high GT score on the ASVAB, i think 130 is the minimum and high scores all across, i got an 88 out of 99 so i was good to go, its not that hard to be selected per say, its harder to stay in the program. you put up w/ a lot of stuff to become a crew chief, some of which i havnt done yet. ive been through AirCrew school which is a lot of swimming and stupid PO's that think they are drill instructors, then i went through SERE school which is just crazy, and i just completed Mech school this week, and Friday i head over to flight school, through all these schools you stay in the training pipeline longer than most any other MOS. ill be in a year and half before i get out to the fleet. most other jobs its 6-12 weeks and your working on your job. i havnt even done my job yet.
its not taht hard to get selected but the pipeline you go through to get the job is quite difficult. but rewarding.