US version has no use for HEMS helicopters at all via missions. Offcourse, if you wan't to alarm HEMS to any medical mission, that's fine and possible. I have been played another countrys version of game, and there is regurarly use and need for HEMS at missions. Hopefully it comes to US version also.
Another mystichal thing. Why police helicopters won't have possible to put patrol route...? Example many highway patrols has helicopters, and those observe traffic from air. So patrol route for Police helicopters?