It depends on a number of variables. The basic requirements are pretty straight forward, but there is a LOT to learn in a short period of time.

The big variables are the quality of the training program, the consistency of the instructors/evaluators, and how much help they will give you if you get in trouble. I have known airline training programs range from 1% to 50% attrition rate. Crappy regionals will usually have a higher fail rate when pilot supply/demand is in their favor, because they don't care about you and can easily replace you.

Indoc is pretty easy.

Turbojet systems are easy if you have an engineering degree or similar background, otherwise expect to work hard in systems class.

As an new-hire FO you may or may not have an oral interview based on the knowledge from indoc and systems.

As far as sim training, your background is a huge factor...

- If you are coming from a CFI job you are going to have to work your butt off. If the program is not stresful, you are probably not trying hard enough and will fail.

- If you have previous 135 turbine time it will be easier...you will be used to the pace, but there are many differences in 121.

- If you are coming from a 121 job in a similar airplane, it should be fairly routine. I did this once (same airplane) and I ended up with a lot of time to kill because I only had to learn those few things which were different frommy previous airline.

Bottom line, be prepared to work hard every waking hour if needed. Do NOT arrive at training with outstanding personal issues...attempt to get a deferred class date so you can resolve your problems first. The guys who are at the start of divorce proceedings always fail out.

Also be wary of taking a job at one of the bottom feeders which are known for throwing new-hires under the bus. If the sim instructors are outside contractors and not company employees, that is bad...they may view you as an annoying nuisance, not a brother pilot.