As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT DEPARTED ICY ON 135 SERVICE FLIGHT AND APPROX 10 MILES SOUTH OF ICY, NR 2 ENGINE FIRE LIGHT ILLUMINATED AND FIRE WARNING HORN SOUNDED. CANCELLED TONE AND IN ABSENCE OF ANY SECONDARY INDICATIONS, RETURNED TO HELIPORT AND MADE A NORMAL APPROACH. MECHANICS DETERMINED THERE WAS A PROBLEM WITH THE SENSOR SWITCH. REMOVED AND REPLACED FLAME DETECTOR WITH A SERVICEABLE DETECTOR. SYSTEM CHECKED OK. (X)