What was found
DURING FLIGHT, THE NR 1 FIRE HANDLE WARNING LIGHT ILLUMINATED. FALSE FIRE WARNING, FLIGHT CONTINUED. DURING TROUBLESHOOTING, FOUND THE NR 1 FWD OUTBOARD FIRE DETECTOR TO HAVE VOLTAGE IN EXCESS OF 11 VOLTS ON PIN B OF THE LARGE CONNECTOR OF THE FIRE CONTROL AMPLIFIER. NORMALLY THIS WOULD INDICATE A DEFECTIVE FLAME DETECTOR. AFTER UNCLAMPING THE WIRE BUNDLE LEADING TO THE DC JUNCTION BOX, CONNECTOR 300P15, FOUND 8 WIRES CHAFED THROUGH THEIR INSULATING SHEATHING. REPAIRED THE WIRING AND RETESTED THE CIRCUIT, SHOWS THE FLAME DETECTOR FUNCTIONING PROPERLY. SUPPLEMENTAL INFORMATION; THE DETECTORS IN THIS A/C HAVE BEEN REPLACED WITH P/N 477223 FLAME DETECTORS IAW COLUMBIA HELICOPTERS, INC. SB 107-26-S0004.