@Huge: are you suggesting that the US crew chiefs can't use a gunner's belt to monitor the load, or is it that with a full load of seated troops there isn't room to do it the old fashioned way -- slide the door open, lie on one's belly, and keep an eye on the load?
The crewman monitors the hookup, transit and release, voice marshalling the aircraft for pickup and drop off to ensure the load is stable and positioned correctly.
I have worked with Navy (and a few times Army) crewman who do precisely that. External loads is a place where the crew chief shines.