N55FB

On November 20, 1997, about 1312 eastern standard time, a Douglas DC-8F-55, N55FB, registered to Agro Air Associates, Inc., operated by Fine Air Services, Inc., as flight 363, experienced an in-flight fire in the No. 4 engine compartment area after takeoff from the Miami International Airport, Miami, Florida. Visual meteorological conditions prevailed at the time and an IFR flight plan was filed for the 14 CFR Part 121 non-scheduled, international, cargo flight. The airplane sustained minor damage and the airline transport-rated captain, first officer, and flight engineer, were not injured. The flight originated about 1303, from the Miami International Airport, Miami, Florida.

The captain stated that climbing through 13,500 feet, the fire warning bell sounded and the fire warning light illuminated for the No. 4 engine. He silenced the fire warning bell and checked the engine instruments for the No. 4 engine, noting no abnormal indications, and reduced the thrust lever to idle. The fire light remained illuminated and he initiated the engine fire emergency checklist; the first fire bottle was discharged. The fire warning light remained illuminated and he waited 30 seconds, then ordered the second fire bottle to be discharged which extinguished the light. He then advised the air traffic controller of a precautionary engine shutdown but did not declare an emergency, and requested "men and equipment standing by"; the flight was returning to Miami. The flight landed uneventfully on runway 9R at 1335, and while rolling off the runway on a high speed taxiway, the fire indication activated again. The first officer visually observed fire from the inboard side of the No. 4 engine cowling and notified the tower controller that they were bailing out of the airplane and stated that they had requested fire rescue be standing by. The controller advised on the frequency that the fire rescue vehicles were responding. The land evacuation emergency checklist was followed and all flightcrew members exited out of the main entry door using the emergency escape rope. The captain stated that while sliding down the escape rope, he reached a point of the rope that contained a knot and he fell about 8 feet to the ground. Airport fire rescue personnel and equipment responded and extinguished the fire.

The flight engineer stated that the No. 3 engine was started first, followed by the No. 4 engine which he noted that the No. 4 engine was slow to accelerate during the start sequence. He reported that the start valve for the No. 4 engine did close as indicated by an increase in the pressure in the manifold. The remaining engines were started at the hold short location and the flight departed. While climbing through 13,000 feet, he first heard the fire warning bell for the No. 4 engine, then observed the fire warning light. The captain confirmed that the fire was from the No. 4 engine and he brought the thrust lever to idle, but the light remained illuminated. The first fire bottle was discharged but the fire warning light remained illuminated. The second fire bottle was discharged and the light extinguished within 2-3 seconds. He further stated that he attempted to move the generator drive lever to the disconnect position but was unable to fully push the lever down. The flight returned and landed uneventfully on runway 9R, then while taxiing on the high speed taxiway, the fire warning light for the No. 4 engine illuminated again. He asked the first officer to verify that a fire condition existed which the first officer confirmed. The remaining engines fire shut-off levers were pulled and they evacuated the airplane out of the main entry door using the escape rope. The flight engineer further stated that the No. 4 constant speed drive (CSD) temperature indicator was normal and the low oil pressure light for the No. 4 CSD was not illuminated until the fire bell and light came on. The airplane was towed to the ramp for further examination.

According to the airport Fire/Property Record report, the fire rescue station was notified of the inbound airplane with a precautionary engine shutdown at 1325, and an Alert 1 was declared which pre-positioned units on the apron. After touchdown, the Alert 1 was changed to an Alert 3 and the pre-positioned units responded and extinguished the fire at the. No. 4 engine position.

Examination of the cockpit revealed that the following circuit breakers were tripped:

1) No. 4 engine continuous ignition 2) No. 4 engine oil cooler door control 3) No. 4 engine low pressure pneumatic temperature control 4) No. 4 engine fuel flow 5) Jet pump valves and oil cooler door override 6) No. 4 engine Anti-ice valve 7) No. 4 engine low pressure pneumatic control 8) No. 4 engine fuel and oil pressure indicator.

Examination of the flight engineer's panel revealed that the No. 2 engine CSD disconnect was activated and a placard was in place which indicated that it was inoperative. Additionally, the No. 4 engine CSD disconnect was noted to be partially activated. All four fire shutoff levers were observed to be pulled which was accomplished in accordance with the land evacuation checklist. Additionally, the No. 3 and No. 4 bottles that contained halon were observed to be discharged which was accomplished in accordance with the Engine Fire checklist.

Examination of the No. 4 engine revealed that the right lower aft cowling had a burn hole, and a blowout panel on the right forward cowling was separated. The area aft of the separated panel exhibited evidence of high heat. A low pressure fuel hose from the "nash" engine driven booster pump to the fuel/oil heat exchanger was failed at the inlet fitting of the heat exchanger. Heat damage was noted to the ignition exciter box, and the nearby generator cables exhibited heat damage which removed the cable insulation. The constant speed drive (CSD) was observed to be severely damaged by fire; the CSD drive shaft was not failed. The inlet fitting for the oil line from the CSD oil tank at the CSD was observed to be failed; the oil line was noted to be free of obstructions. The CSD oil tank was noted to be empty and the engine oil tank was noted to be 2/3 full. The three-inch diameter pneumatic shutoff butterfly valve assembly "start valve", was noted to be in the full "open" position. A pneumatic duct of about 2 feet in length on the inboard side of the No. 4 engine was noted to be separated from its' slip joint assembly. That location was just forward of the pneumatic starter assembly. Heavy sooting was noted on the inboard forward section of the engine in the area of the engine oil supply tank. Examination of the pneumatic starter housing revealed damage, but all starter reduction gears were intact with no evidence of failure and the starter output shaft was not failed. Examination of the CSD cable pulley system for the CSD disconnect revealed it was frozen and could not be moved, the CSD had not been disengaged. The fuel pressure and dump valve was noted to have a section missing near a steel fitting located at the bottom of the unit as viewed when installed on the engine. The oil cooler door was noted to be in the full "open" position and the heat exchanger door was fully closed. The start valve which was found in the full open position was removed for further examination. The failed fuel line, oil line, pneumatic starter assembly, generator cables, and fuel pressure and dump valve were removed from the airplane and sent to the NTSB Metallurgy Laboratory located in Washington, D.C.

Metallurgical examination of the pneumatic starter assembly by the NTSB Metallurgy Laboratory revealed that fragments of the inner wall were missing, and a portion of the outer wall was missing. The blades were bonded to the housing and could not be moved by hand. The outboard portion of the blades exhibited uneven wear and there was no evidence of bent blades. Examination of the failed fuel line, fuel pressure and dump valve assembly, and failed oil line revealed no evidence of preexisting cracks. Examination of the generator control cables revealed no evidence of electrical arching. A copy of the metallurgy report is an attachment to this report.

Visual examination of the start valve revealed a foreign substance along the length circumferentially of the inside diameter of the valve body. The threaded butterfly backing plate could not be moved by hand to the fully closed position; binding was noted before the fully closed position. No lead seals were present externally. Heat damage was noted to the electrical portion of the solenoid valve and to the cover of the actuator body. Marks associated with a hammer were noted on the exterior portion of the valve body. Disassembly of the start valve was accomplished which revealed blockage of one of the top orifices of the solenoid switcher valve housing. Blockage of the other top orifice was also noted by a fine granular red colored substance associated with the preformed packing. The material was submitted to the manufacturer of the start valve for analysis which revealed it to be burnt silicon with small traces of dry film lubricant. The silicon was similar to that used in manufacturing of the silicon "O-rings." The dry film lubricant is used on the actuator and piston to reduce wear. Following removal of the actuator body, from the valve body, the threaded butterfly backing plate was noted to move freely from the full open to full closed position. Visual check of the butterfly valve disk revealed no evidence of malfunction. The pneumatic piston assembly would not travel the full length of the actuator body. There was no evidence that the threaded butterfly backing plate was adjusted to compensate for the failure of the pneumatic piston assembly to go full travel toward the closed position. The filter assembly was pressure checked and found to be...