I am based in ATL as a FO. This is just a guess because it changes all the time. FOs are going all over the country out of training but most junior is always DTW to hold a line the fastest. ATL has a bunch of FO's with upgrades in. We have not seen any real growth in Atlanta. The growth has been DTW, DEN, and DFW. I would say most likely 6mo to get a line in Atlanta. Our flying is just 200s. They are not all short. We have 30min to 1 hour 30min legs. Delta doesn't use the 200 for much longer stuff unlike United does. The good part about the flying in Atlanta you get good at it fast taking 4 to 5 leg days. If you have any other questions feel free to PM me. I have been very happy with Skywest it is a great company.