Depends on your experience - IIRC a F3 Short Course was about 2-3 months but an ab-initio F3 Long Course was the best part of 6 months. Don't forget that the majority of Reaper drivers are experienced operators from other fleet types (F16, B1B, F15, Tornado, Harrier, Apache, Nimrod, etc...). The first few ab-initio (or UPT as the US call them) have taken a little extra training to bring up to speed.