A good idea is to have a Predator Aircraft leading the Helicopter as a "Threat Warning" aid. Threat Warning analysts can tip off the Helicopter of an impending threat. Terrorist cannot hide to well from infrared cameras. The Predators are capable of carrying Hellfires to pick off terrorist before they can fire at friendly forces.
Just an idea
I think that the problem is that the Predators are controlled by either the USAF or the CIA. Most of the helicopters are Army (and some are Navy/Marine). It might sound like a simple problem to solve, but the Predators are in BIG demand and they won't be given up easily to 'run interference for every chopper mission.
The problem reminds me of Gulf War I when the Air Force resisted pulling their better tactical aircraft (F-15E's) from the main battle effort to hunt for SCUD's. They knew that it would require a major effort to kill even a few of them while they could make a tremendous impact on the Iraqi Army and air defenses.