Flight hours/ on duty US military Pilots (Manuscript questions)

[Ariffraff]

Your friendly neighborhood writer checking in.
How long can a military pilot fly in one day. I have a character that needs to fly from Juba South Sudan to Andrews AFB (no it's not the president). I was planning on using an Air Force cargo plane. (Sure I'd love a plane recommendation too.)
If I wanted a sense of realism would I need two flight crews? Would the plane need to land for fuel in route? Could both flight crews be on the plane at take off?
Are there any obvious things I could be missing?

[Fryy/Avocadoflight]

If it helps I can give my father a call soon and ask him some of your questions. He flew C5's back in the 80's and early 90's, so not sure how much the regulations have changed if at all since.

[Ariffraff]

that would be amazing and very much appreciated.

[KB4TEZ]

here's a start

https://aviation.stackexchange.com/questions/8784/do-military-pilots-have-flight-rest-hours-regulation