For all who only want to look :
Demo Map and texturefile.
For the mappers :
Prefabs and texturefile.
There's five prefabs in the ZIP. One for the body. One for the main rotor. One for the tail rotor. One for the side door. One for the cockpit doors.
You might also download the map too to have an idea of what I'm talking about.
You might want to rather use 'spinning rotor-textures' than the prefabs, if the heli is intended to be flying.
Also if you use the rotor prefabs, you might want to rotate the rotors to a position that fits your map best.
The door's are separate prefabs to let you decide their position.
All prefabs except the body only use one gray texture. The body has an additional cockpit texture.
I also have a blackhawk .wav file, but can't get it to load in UEd. Also it's not really fit for looping playback. If any of you is good with sounds I can supply it.
And for the really lazy. Here's a final screenshot :