What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23)During normal cruise, the left engine experienced a 20% loss of torque. The crew was informed by company maintenance personnel that they might be experiencing a possible fuel nozzle leak on that engine. The #1 engine fire warning light illuminated, and the fire horn activated. The captain secured the engine and discharged the #1 fire suppression agent. Immediately following the discharge, the associated warning lights on the fire handle and condition lever extinguished. An uneventful single engine landing was completed and the passengers deplaned without further incident. Evidence of thermal damage was found in the aft section of the engine in the area of the lower turbine support case. Examination of the system revealed that 3 of the 144 'o' rings associated with the 14-nozzle fuel system were deteriorated or damaged. Also, during the investigation, testing at the engine manufacturer's facility revealed that the inside diameter of the copper gasket used at the fuel drain nipple was 30 to 40% larger than required. This resulted in misalignment and a leak at the fitting.
As the FAA filed it
(-23)DURING NORMAL CRUISE, THE LEFT ENGINE EXPERIENCED A 20% LOSS OF TORQUE. THE CREW WAS INFORMED BY COMPANY MAINTENANCE PERSONNEL THAT THEY MIGHT BE EXPERIENCING A POSSIBLE FUEL NOZZLE LEAK ON THAT ENGINE. THE #1 ENGINE FIRE WARNING LIGHT ILLUMINATED, AND THE FIRE HORN ACTIVATED. THE CAPTAIN SECURED THE ENGINE AND DISCHARGED THE #1 FIRE SUPPRESSION AGENT. IMMEDIATELY FOLLOWING THE DISCHARGE, THE ASSOCIATED WARNING LIGHTS ON THE FIRE HANDLE AND CONDITION LEVER EXTINGUISHED. AN UNEVENTFUL SINGLE ENGINE LANDING WAS COMPLETED AND THE PASSENGERS DEPLANED WITHOUT FURTHER INCIDENT. EVIDENCE OF THERMAL DAMAGE WAS FOUND IN THE AFT SECTION OF THE ENGINE IN THE AREA OF THE LOWER TURBINE SUPPORT CASE. EXAMINATION OF THE SYSTEM REVEALED THAT 3 OF THE 144 'O' RINGS ASSOCIATED WITH THE 14-NOZZLE FUEL SYSTEM WERE DETERIORATED OR DAMAGED. ALSO, DURING THE INVESTIGATION, TESTING AT THE ENGINE MANUFACTURER'S FACILITY REVEALED THAT THE INSIDE DIAMETER OF THE COPPER GASKET USED AT THE FUEL DRAIN NIPPLE WAS 30 TO 40% LARGER THAN REQUIRED. THIS RESULTED IN MISALIGNMENT AND A LEAK AT THE FITTING.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.