You would just wait till you have a firm start date with the DoD. I knew about 3-4 weeks out. Then you would drop your resignation letter to the FAA (2-week notice). The HR people will reach out to each other so that your SF-50 and all other information gets transfered (Annual leave and Sick leave) I quit with the DoD on a Friday and started with the FAA on Monday. Very painless process.Wouldn't resigning your position in order to leave for a new job result in a break in service? For inter-DOD transfers the receiving HR has you provide a POC at your agencies HR and they work out a date that works for both agencies. My facility didn't have input, if I recall correctly, & HR made the date determination.