The crew chief is never used as one, he always just ends up co piloting (on the BAF ones anyway)
Sorry bud, rotary multi-crew have 2 pilots and a crew chief at minimum. The crew chief deals with checking the aircraft has clear landing spots and spots for the pilot when landing in fields etc., mans one of the guns if necessary, checks and secures cargo (be that crates or grunts) and manages anything on the craft that doesn't involve actually flying the thing.
Unless you're on about what happens in Arma?
Dewch ymlaen, ddim ond y gorau ydy dda ddigon.
Bringing the pain since 2013!
First official recipient of the TWC Distinguished Flying Cross
"Knows his stuff in general, a really sexy voice. Everything you need from an IC." TheLocalPub: 2017