Narrative:

Prior to departure; maintenance was working a fire loop issue on engine #4. They changed loop B and subsequently deferred loop a. All tests passed prior to departure. Engine start; taxi; takeoff and initial climb out to 4;000 ft were normal.about 5 minutes into the flight; after being cleared to climb to 16;000 ft; we got a master warning light and alarm bell; with a fire eng 4 EICAS message and fire light in the #4 fuel control switch and #4 fire handle. Per company QRH procedures; I reduced the #4 thrust lever to close; directed the fire engine checklist; and coordinated with ARTCC for level off at 10;000 ft.with the fire engine 4 message still indicated I directed activation of the fire bottle. After 30 seconds the message was still displayed; and I directed firing the other fire bottle for #4. The fire eng message remained displayed and I began to consider an emergency return for an overweight landing. After approximately 3-4 minutes; the fire eng message was no longer displayed; and I had the engine visually scanned both from the first officer window and from the main deck windows. No abnormal indications were noted by visual inspection; and there were no indications of fire on any indicators. I elected to jettison fuel and make a 3-engine approach and landing. We declared an emergency; jettisoned the fuel; and accomplished the landing on runway 26R at our departure airport. Emergency equipment met us on arrival and their inspection revealed no apparent damage to the engine. We taxied to the gate and deplaned.

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Original NASA ASRS Text

Title: A number four engine fire warning during initial climb; later determined to have been false; led the B747-400 flight crew to shut down the engine; discharge both fire bottles; declare an emergency; dump fuel and land uneventfully back at their departure airport.

Narrative: Prior to departure; Maintenance was working a Fire Loop issue on engine #4. They changed Loop B and subsequently deferred Loop A. All tests passed prior to departure. Engine start; taxi; takeoff and initial climb out to 4;000 FT were normal.About 5 minutes into the flight; after being cleared to climb to 16;000 FT; we got a Master Warning Light and alarm bell; with a Fire Eng 4 EICAS message and fire light in the #4 Fuel Control Switch and #4 Fire Handle. Per company QRH procedures; I reduced the #4 Thrust Lever to Close; directed the Fire Engine Checklist; and coordinated with ARTCC for level off at 10;000 FT.With the Fire Engine 4 message still indicated I directed activation of the Fire Bottle. After 30 seconds the message was still displayed; and I directed firing the other Fire Bottle for #4. The Fire Eng message remained displayed and I began to consider an emergency return for an overweight landing. After approximately 3-4 minutes; the Fire Eng message was no longer displayed; and I had the engine visually scanned both from the FO window and from the main deck windows. No abnormal indications were noted by visual inspection; and there were no indications of fire on any indicators. I elected to jettison fuel and make a 3-engine approach and landing. We declared an emergency; jettisoned the fuel; and accomplished the landing on runway 26R at our departure airport. Emergency equipment met us on arrival and their inspection revealed no apparent damage to the engine. We taxied to the gate and deplaned.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.