There used to be many more trades for airforce techs. There are in fact only 4 MOC 500 trades now. Three of them you can enter from right off the street, those being AVN, AVS, and ACS. The 4th is NDT (non-destructive testing). You have to be one of the previous three trades, but I can't remember which one(s) it is. The reason the AVN course went from 6 months to 18 months was because the Airforce realized that an AVN tech could not be properly trained in only 6 months (lots of feedback from the units told them so). It just wasn't possible to teach a tech what he needed to know in only 6 months what used to take the combined old trades much longer. In fact, the 18 months is "still" shorter than the time it would take if someone would do all of the training for the other old trades.
Every new course will have teething pains, but I do find that CFSATE tends to take forever to modify a course (same thing happened on my course). You will find that even when you go to your unit after trg that there are alot of mistakes in the CFTOs, pubs, etc. There will be constant messages coming out to correct the mistakes. The difference in the Airforce is that you will be able to suggest and the changes will happen most of the time, but not all of the time. I've done both sides of the coin, Army (only two years Reserve time) and Airforce. You'll enjoy being an AVN tech, but will be frustrated at times.
With the Forced reduction in the mid-nineties, there is a large experience gap for techs with 10 to 15 years in. It is a very good time to get into one of the 500 series trades as there will be a great need for higher ranks in 5 to 10 years. Expect to see alot of promotions.
Later....