When I was routinely going on Boeing Flight Tests, we tested 7 days per week, naturally people got tired of working weekends and wanted some time off. So on weekends we'd sometimes get an experienced, top-notch flight test pilot, and a young 'newbe' pilot who was simply learning the ropes.
The idea was that the experienced pilot would fly all the tricky test conditions while explaining things to the newbe. If anything happened to the experienced pilot, the newbe was simply expected to get the aircraft on the ground in one piece.
I suspect the USAF has something similar in mind - the loady would get some basic training on operation of the aircraft and how to do a straightforward landing. If the pilot is somehow incapacitated, the loady's job would simply be to return to base and get the aircraft on the ground in one piece.