MLG HAS AN ENGINE FIRE SHORTLY AFTER TKOF.

Narrative

FLT WAS DEPARTING SFO WHEN WE EXPERIENCED FIRE INDICATIONS ON #4 ENG. THE #4 ENG WAS SHUT DOWN; EXTINGUISHERS DISCHARGED AND SUBSEQUENT ACTIONS FOLLOWED PER CHKLIST. AS I CAN BEST RECALL; COCKPIT FIRE INDICATIONS WENT OUT WITH JUST THRUST LEVEL CUT OFF. ATC WAS NOTIFIED OF OUR INTENT TO RETURN TO SFO FOR LNDG. ATC ASKED US THE REASON FOR OUR RETURN TO THE ARPT. I EXPLAINED THAT WE HAD EXPERIENCED FIRE INDICATIONS ON #4 ENG AND THAT THE ENG HAD BEEN SHUTDOWN. ATC ASKED IF WE WERE DECLARING AN EMER. I SAID; 'NOT AT THIS TIME;' BUT THAT WE WOULD LIKE PRIORITY HANDLING BACK TO THE ARPT. THE F/A'S AND PAX WERE NOTIFIED OF OUR RETURN FOR LNDG DUE TO SHUTDOWN OF #4 ENG. SFO OPS WAS ALSO NOTIFIED OF OUR RETURN TO SFO AND THE REASON WHY. FLT LANDED AND RETURNED TO THE GATE WITH NO FURTHER INCIDENT. I HAVE SINCE BEEN INFORMED THAT THE CAUSE OF THE FIRE INDICATIONS WAS DUE TO AN INCORRECTLY INSTALLED FUEL NOZZLE WHICH LEAKED AT HIGH PWR SETTINGS AND ACTUALLY DID START A FIRE. PRIOR TO THE DEP OF FLT; I NOTICED THE MECH IN SFO HAD THE #4 ENG CASE OPEN. I ASKED HIM WHAT HE WAS CHKING ON THE ENG. HE INFORMED ME THAT HE WAS DOING A ROUTINE FUEL LEAK CHK AND INDICATED EVERYTHING WAS FINE. HE DID NOT TELL ME THAT MAINT WAS CONCERNED OF A POSSIBLE FUEL LEAK DUE TO THE POSSIBILITY OF AN INCORRECTLY INSTALLED FUEL NOZZLE; WHICH WAS RPTED BY THE MECH THAT INSTALLED IT AND WHO WAS UNCERTAIN THAT IT WAS DONE CORRECTLY. MY QUESTIONS ARE: 1) WHY WAS THE ACFT NOT GNDED BY MAINT CTL; UNTIL THE FUEL NOZZLE IN QUESTION COULD BE CHKED FOR CORRECT INSTALLATION. 2) WHY WASN'T I; AS THE PIC; FULLY BRIEFED BY MAINT ON ALL THE PERTINENT INFO CONCERNING THAT ENG SO THAT I MIGHT HAVE BEEN INFORMED AND ABLE TO MAKE MY OWN DECISIONS CONCERNING THE SITUATION. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: CONFIRMED THAT HE DID NOT REQUEST THE EMER GND EQUIP TO STAND BY FOR HIS LNDG. COUNSELED HIM THAT IT WAS THOUGHT TO BE VERY CHEAP INSURANCE AND HE AGREED; SAYING THAT IF HE HAD IT TO DO OVER AGAIN; HE WOULD REQUEST THE EQUIP. WE AGREED THAT DECLARING AN EMER WAS UNNECESSARY AS LONG AS ALL OTHER FACTORS HAD BEEN TAKEN CARE OF. CALLBACK CONVERSATION WITH RPTR ACN 99070: CALLED F/O ONLY TO ASK IF THE EMER GND EQUIP HAD BEEN REQUESTED. HE SAID IT HAD NOT. SUPPLEMENTAL INFO FROM ACN 98768: WE FEEL AN EMER SHOULD HAVE BEEN DECLARED WITH THE EMER EQUIP STANDING BY ON LNDG. SUPPLEMENTAL INFO FROM ACN 98769: UPON SHOP CHK (FLOW BENCH); REMOVED MANIFOLDS WERE DEMONSTRATED TO HAVE MINOR EXTERNAL LEAKAGE AT SELECTED FUEL NOZZLE POSITIONS. MANIFOLDS WERE REMOVED FROM FLOWBENCH AND DISASSEMBLED; WHERE IT WAS DISCOVERED THAT FUEL NOZZLE PACKING HAD BEEN INADVERTENTLY OMITTED FROM EACH NOZZLE DURING INSTALLATION INTO THE MANIFOLD.