if you are having problems rendering it. you should render it in parts and comp it together.
you don't need to worry about lots of passes. just make a surface shader and set the matte opacity to black. apply that to the helicopter (or background depending on what you want to render.) when you render it now, the helicopter will have no alpha and will render black.
so once you have done this for both the BG and the helicopter you should have a background with the outline of the helicopter and the hind by itself on black. now you can use nuke or shake, toxic or whatever to over the helicopter render onto the bg.