Can you go from air force reservist to air force active duty?

Yes, but it is very difficult. Every fiscal year (October to October for government), they open up about 10-20 slots for reservists to go into active for critically manned fields. Those fields are Security Forces, Combat Controllers/Pararescue, and TAC-P. Normally those are the only ones offered. You would need to enter into Active Duty in one of those fields and then cross train if needed into your desired field after 3 years. They are very selective and very difficult to get. Also, you will more often than not lose rank going in. It will all be based on your cumulative active time while in the reserves. You need to talk to your representative at MPF for more information about the checklist and processing.