Let me preface this with, "I'm active duty", but. The training process is the same. You'll obviously have to find a unit that will "hire" you. Then when all that's done, you'll have to go through 6-12 weeks of officer training school. Then you'll have to go to UPT, which was a year when I went through, I don't know how long it is now. Then you go to the FTU for your airframe, Altus, Little Rock, Kelly (for the heavies). The FTU's range anywhere from 3.5 months to 6 months. I went from starting OTS to graduating my FTU (C-17) and finishing combat/water survival training in just shy of 24 months. I had no casual time or delays in training so I'd say that's pretty close to the quickest you could do it. Good Luck.