Systems that tell you where the wires are, only if you have already told them where the wires are, bring the words fireguards and chocolate to mind, especially if you didn't know where they were in the first place. Similarly systems that tell you where the wires are as long as they are live fall into much the same category. Which leaves systems that can tell you where the wires are even if you didn't know where they are, and do so whether live or not. Such systems exist (witness the link in Nutloose's #108) :-
http://www.tc.faa.gov/its/worldpac/techrpt/ar0825.pdf
They have the advantage of working anywhere in the world, using laser beams (which no doubt creates some operational restraints). Nonetheless that would appear to be the best solution. They can be fitted into any low flying aircraft, rotary or otherwise. If we trial off the shelf systems already in use, incorporating them according to the regs, and not double the cost by modifying them to uneconomic levels, isn't that the way to go?
I see that tuc tells us the technology was here back in the 1980's...