It they are going to a new call they are allowed to do so. We use Medevac all the time on the way to pick up the patient. We don't when we are going home empty. But I have done three turns in a row before headed back to base and even then if we are going back to base to pick up another patient we can use Medevac.

But a dirtbag charter company on the other hand who just doesn't want to wait in line can apparently use it to cut in line.