With wire strikes one of the greatest hazards to helicopter operations, Safe Flight Instrument Corp. has received STC certification for its Powerline Detection System for Bell 206 helicopters. It works by sensing the electromagnetic field created by power lines, warning helicopter pilots when they are in the vicinity of live wires. The system emits an auditory alert, warning pilots of a power-line hazard, even if it is unseen. The warning increases in frequency as the helicopter gets closer to a live power line. A warning light also illuminates on a cockpit indicator. The system warns of a sensed power line whether the helicopter is approaching from under, over, or at an oblique angle. It does not warn against all power lines, the company notes.