Narrative:

I departed manchester, nh, carrying hazardous material, which we were authority/authorized to carry from manchester to morristown, tn. All indications of engine function were nominal throughout the climb and the first part of cruise. The WX in the area of our departure was low IFR. In fact, our departure alternate was albany, ny. Much of the en route airports were also low IFR. While flying towards pottstown VOR, and overhead morristown, nj, the left fire annunciator light illuminated. I immediately brought the left throttle back to idle. The light remained illuminated. I put the throttle in the cutoff position and closed the firewall shut off valve. The light extinguished. Since the aircraft will not sustain flight on one engine at that altitude I requested lower and where the nearest good WX airport was. I used pan-pan due to frequency congestion ATC indicated pne or phl and asked if I was declaring an emergency. I said no. At this time the left fire light came on. I blew the first fire bottle. The light extinguished momentarily then came back on. As I was blowing the second fire bottle I declared an emergency (after blowing the second bottle the light stayed out). I was given a vector towards phl. ATC inquired as to the nature of the problem. I explained the problem and asked them to notify my company. I was vectored to an ILS for runway 27R at phl. When asked if I needed crash equipment, I said I did not foresee a problem but to have them standby. I laned west/O a problem. In hindsight, I might have done things differently. The problem seemed to have been an engine bleed air leak in the cowling. Perhaps firing the fire bottles was not needed. And perhaps priority handling could have supplanted declaring an emergency.

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Original NASA ASRS Text

Title: LEFT ENGINE FIRE WARNING. ENGINE FIRE LIGHT. BOTH BOTTLES DISCHARGED. PAN, PAN. ZNY GAVE VECTORS TO PHL FOR LNDG.

Narrative: I DEPARTED MANCHESTER, NH, CARRYING HAZARDOUS MATERIAL, WHICH WE WERE AUTH TO CARRY FROM MANCHESTER TO MORRISTOWN, TN. ALL INDICATIONS OF ENG FUNCTION WERE NOMINAL THROUGHOUT THE CLB AND THE FIRST PART OF CRUISE. THE WX IN THE AREA OF OUR DEP WAS LOW IFR. IN FACT, OUR DEP ALTERNATE WAS ALBANY, NY. MUCH OF THE ENRTE ARPTS WERE ALSO LOW IFR. WHILE FLYING TOWARDS POTTSTOWN VOR, AND OVERHEAD MORRISTOWN, NJ, THE L FIRE ANNUNCIATOR LIGHT ILLUMINATED. I IMMEDIATELY BROUGHT THE L THROTTLE BACK TO IDLE. THE LIGHT REMAINED ILLUMINATED. I PUT THE THROTTLE IN THE CUTOFF POS AND CLOSED THE FIREWALL SHUT OFF VALVE. THE LIGHT EXTINGUISHED. SINCE THE ACFT WILL NOT SUSTAIN FLT ON ONE ENG AT THAT ALT I REQUESTED LOWER AND WHERE THE NEAREST GOOD WX ARPT WAS. I USED PAN-PAN DUE TO FREQ CONGESTION ATC INDICATED PNE OR PHL AND ASKED IF I WAS DECLARING AN EMER. I SAID NO. AT THIS TIME THE L FIRE LIGHT CAME ON. I BLEW THE FIRST FIRE BOTTLE. THE LIGHT EXTINGUISHED MOMENTARILY THEN CAME BACK ON. AS I WAS BLOWING THE SEC FIRE BOTTLE I DECLARED AN EMER (AFTER BLOWING THE SEC BOTTLE THE LIGHT STAYED OUT). I WAS GIVEN A VECTOR TOWARDS PHL. ATC INQUIRED AS TO THE NATURE OF THE PROB. I EXPLAINED THE PROB AND ASKED THEM TO NOTIFY MY COMPANY. I WAS VECTORED TO AN ILS FOR RWY 27R AT PHL. WHEN ASKED IF I NEEDED CRASH EQUIP, I SAID I DID NOT FORESEE A PROB BUT TO HAVE THEM STANDBY. I LANED W/O A PROB. IN HINDSIGHT, I MIGHT HAVE DONE THINGS DIFFERENTLY. THE PROB SEEMED TO HAVE BEEN AN ENG BLEED AIR LEAK IN THE COWLING. PERHAPS FIRING THE FIRE BOTTLES WAS NOT NEEDED. AND PERHAPS PRIORITY HANDLING COULD HAVE SUPPLANTED DECLARING AN EMER.

Data retrieved from NASA's ASRS site as of July 2007 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.