USMC helicopter crew chief?

i am looking for some info on MOS 6173 helicopter crew chief for the Marine Corps. my question is, is this an MOS i can go into right after boot camp? the word chief makes it confusing, although it says Pvt.- GySgt. so i'm not sure (i know i sound stupid for asking this, but i seriously don't know) . also what do you do in this MOS exactly, as in day to day what do you do as a helicopter crew chief? thanks any advice and help is appreciated :)