Shetlander
I think that FB Heliservices supply some contractors to the military but am not aware that they supply courses to guys off the street, I may be wrong!! The company has a lot of good guys working for it so if you do go there you will get good instruction.
I do not wish to be rude, but how much homework have you done on this subject? There are lots of different ideas of what a crewman is.
Heads down, look out for the flack