Power and utility lines are a very real danger for helicopter pilots. In the event of a collision with horizontal wires (wire strike), the helicopter could become entangled in the severed wires. Entanglement could lead to damage to the flight controls and loss of function in landing gears.
Wire strike kits are designed to reduce the possibility of entanglements and damage by proactively slicing the wires. The kits are comprised of high tensile steel serrated blades affixed above the cockpit, below the nose, and sometimes a windshield deflector. Most kits have been extensively tested and proven to be effective against multiple wire strikes.
This safety equipment has become standard issue for most police and medical copters. They have been quickly adopted by pilots who may be required to fly in populated areas. In the case of an autorotation or forced landing, a wire strike kit could be the difference between a survivable landing and a fiery death.