Who has priority on Space-A flights?

The DoD has established a priority system for allocating Space-A air travel. This system is described in detail in Section 4, Space Available Passenger Transportation, DoD 4515.13. The general categories: Category I: Emergency Leave, Unfunded Travel. Category II: Accompanied Environmental and Morale Leave (EML). Category III: Ordinary Leave, Relatives, House Hunting Permissive TDY, Medal of Honor Holders, and Foreign Military. Category IV: Unaccompanied EML. Category V: Permissive TDY (Non-House Hunting), Students, Dependents, Post Deployment/Mobilization Respite Absence, and Others. Category VI: Retired, Dependents, Reserve, ROTC, NUPOC and CEC members. Note: More details concerning each category are available at the following weblink PDF file, page 36:

http://www.dtic.mil/whs/directives/corres/pdf/451513p.pdf