Narrative:

After tow out, and as the tug was being disconnected, we were in the process of starting the left engine (the right was already running and operating normally). As starter cut out occurred the captain requested that I call for taxi, and he was very intent on proceeding to the departure end of the runway ahead of an air carrier large transport who ground control had earlier informed us was to taxi before us, however they were not quite yet ready to go. As I wanted to receive permission to taxi as quickly as possible, since the captain had already begun to advance the power to being movement, I rapidly made my radio transmission to ground control and simultaneously began performing the after start checklist. Events were further compounded by the need to immediately clear the right wing tip, as we began to taxi past the air carrier large transport on our right. The wing tip clearance between aircraft on the parallel taxiway and the ramp at sna is not great, and as we were operating the largest airplane currently allowed into the airport, and since we were taxiing past an identical type aircraft (ie, same wing tip height above the ground as ours) parked at the spot closest to the parallel taxiway we were on, the need to closely monitor the wing tip clearance was paramount. Shortly after passing by the other large transport sna ground control informed us of smoke and flames coming from our left engine. The captain stopped the aircraft and set the parking brake. At this time, as he looked at the engine instruments (there was no fire or overheat indication at any time), he stated that the left engine had ceased running and I observed that it was winding down. This was the first opportunity that I had had, since starter cutout, to observe the left engine instruments. We were discussing the matter between ourselves and trying to get more information from ground control as to what the engine was doing, (ie, did they still see fire?) when several fire trucks/veh's arrived and parked themselves near the front of the aircraft. By this time the captain had positioned the fuel control switch to 'off,' and we were debating whether or not to pull the fire handle (which was by this time strongly suggesting). Also at this time we began to have the fire chief enter the loop, initially by relay through ground control, and ultimately, after a radio frequency change, directly communicating to us. This direct communication took, in my opinion, quite some time to establish, and some confusion existed for a time as to just what the left engine was doing (from an outside observer's station). Due to our inability to get precise and timely information about the exact state of the engine, and even though there were still no indications in the cockpit of any fire or overheat, the captain elected to pull the fire handle, and as a further precaution, fired 1 fire bottle into the engine. Eventually all concerned were satisfied that the left engine was secured, and after making passenger announcement to our passenger, we were towed back to the gate. Some 6 hours later, after an examination of the engine by our company mechanics, re-installation of a new fire bottle, and a routine but closely monitored re-start, we departed sna for an uneventful flight to destination. Since no mechanical problems were noted with the engine during subsequent ground and flight operation, I can only conjecture what might have caused these events. After much thought, I have come to the conclusion that it is at least possible that positioning the engine bleed valve switch to 'on' (a part of the after start checklist and to provide air to the respective air conditioning pack) while simultaneously advancing the throttle for taxi after starter cutout (at 50% N2) but prior to the engine reaching stabilized idle (about 62% N2) may, in some cases, create conditions that the fuel control cannot handle. In the future, it is my firm intention to not allow completion of the after start checklist to interfere with closer monitoring of engine instruments until stabilized idle.

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Original NASA ASRS Text

Title: ACFT EXPERIENCED APPARENT ENGINE FIRE AT BEGINNING OF TAXI. ATC BOTH REPORTED THE APPARENT FIRE TO THE FLT CREW AND CALLED FOR THE EMERGENCY EQUIPMENT.

Narrative: AFTER TOW OUT, AND AS THE TUG WAS BEING DISCONNECTED, WE WERE IN THE PROCESS OF STARTING THE LEFT ENG (THE RIGHT WAS ALREADY RUNNING AND OPERATING NORMALLY). AS STARTER CUT OUT OCCURRED THE CAPT REQUESTED THAT I CALL FOR TAXI, AND HE WAS VERY INTENT ON PROCEEDING TO THE DEP END OF THE RWY AHEAD OF AN ACR LGT WHO GND CTL HAD EARLIER INFORMED US WAS TO TAXI BEFORE US, HOWEVER THEY WERE NOT QUITE YET READY TO GO. AS I WANTED TO RECEIVE PERMISSION TO TAXI AS QUICKLY AS POSSIBLE, SINCE THE CAPT HAD ALREADY BEGUN TO ADVANCE THE PWR TO BEING MOVEMENT, I RAPIDLY MADE MY RADIO XMISSION TO GND CTL AND SIMULTANEOUSLY BEGAN PERFORMING THE AFTER START CHKLIST. EVENTS WERE FURTHER COMPOUNDED BY THE NEED TO IMMEDIATELY CLR THE RIGHT WING TIP, AS WE BEGAN TO TAXI PAST THE ACR LGT ON OUR RIGHT. THE WING TIP CLRNC BTWN ACFT ON THE PARALLEL TXWY AND THE RAMP AT SNA IS NOT GREAT, AND AS WE WERE OPERATING THE LARGEST AIRPLANE CURRENTLY ALLOWED INTO THE ARPT, AND SINCE WE WERE TAXIING PAST AN IDENTICAL TYPE ACFT (IE, SAME WING TIP HEIGHT ABOVE THE GND AS OURS) PARKED AT THE SPOT CLOSEST TO THE PARALLEL TXWY WE WERE ON, THE NEED TO CLOSELY MONITOR THE WING TIP CLRNC WAS PARAMOUNT. SHORTLY AFTER PASSING BY THE OTHER LGT SNA GND CTL INFORMED US OF SMOKE AND FLAMES COMING FROM OUR LEFT ENG. THE CAPT STOPPED THE ACFT AND SET THE PARKING BRAKE. AT THIS TIME, AS HE LOOKED AT THE ENG INSTRUMENTS (THERE WAS NO FIRE OR OVERHEAT INDICATION AT ANY TIME), HE STATED THAT THE LEFT ENG HAD CEASED RUNNING AND I OBSERVED THAT IT WAS WINDING DOWN. THIS WAS THE FIRST OPPORTUNITY THAT I HAD HAD, SINCE STARTER CUTOUT, TO OBSERVE THE LEFT ENG INSTRUMENTS. WE WERE DISCUSSING THE MATTER BTWN OURSELVES AND TRYING TO GET MORE INFO FROM GND CTL AS TO WHAT THE ENG WAS DOING, (IE, DID THEY STILL SEE FIRE?) WHEN SEVERAL FIRE TRUCKS/VEH'S ARRIVED AND PARKED THEMSELVES NEAR THE FRONT OF THE ACFT. BY THIS TIME THE CAPT HAD POSITIONED THE FUEL CONTROL SWITCH TO 'OFF,' AND WE WERE DEBATING WHETHER OR NOT TO PULL THE FIRE HANDLE (WHICH WAS BY THIS TIME STRONGLY SUGGESTING). ALSO AT THIS TIME WE BEGAN TO HAVE THE FIRE CHIEF ENTER THE LOOP, INITIALLY BY RELAY THROUGH GND CTL, AND ULTIMATELY, AFTER A RADIO FREQ CHANGE, DIRECTLY COMMUNICATING TO US. THIS DIRECT COM TOOK, IN MY OPINION, QUITE SOME TIME TO ESTABLISH, AND SOME CONFUSION EXISTED FOR A TIME AS TO JUST WHAT THE LEFT ENG WAS DOING (FROM AN OUTSIDE OBSERVER'S STATION). DUE TO OUR INABILITY TO GET PRECISE AND TIMELY INFO ABOUT THE EXACT STATE OF THE ENG, AND EVEN THOUGH THERE WERE STILL NO INDICATIONS IN THE COCKPIT OF ANY FIRE OR OVERHEAT, THE CAPT ELECTED TO PULL THE FIRE HANDLE, AND AS A FURTHER PRECAUTION, FIRED 1 FIRE BOTTLE INTO THE ENG. EVENTUALLY ALL CONCERNED WERE SATISFIED THAT THE LEFT ENG WAS SECURED, AND AFTER MAKING PAX ANNOUNCEMENT TO OUR PAX, WE WERE TOWED BACK TO THE GATE. SOME 6 HRS LATER, AFTER AN EXAMINATION OF THE ENG BY OUR COMPANY MECHS, RE-INSTALLATION OF A NEW FIRE BOTTLE, AND A ROUTINE BUT CLOSELY MONITORED RE-START, WE DEPARTED SNA FOR AN UNEVENTFUL FLT TO DEST. SINCE NO MECHANICAL PROBS WERE NOTED WITH THE ENG DURING SUBSEQUENT GND AND FLT OPERATION, I CAN ONLY CONJECTURE WHAT MIGHT HAVE CAUSED THESE EVENTS. AFTER MUCH THOUGHT, I HAVE COME TO THE CONCLUSION THAT IT IS AT LEAST POSSIBLE THAT POSITIONING THE ENG BLEED VALVE SWITCH TO 'ON' (A PART OF THE AFTER START CHKLIST AND TO PROVIDE AIR TO THE RESPECTIVE AIR CONDITIONING PACK) WHILE SIMULTANEOUSLY ADVANCING THE THROTTLE FOR TAXI AFTER STARTER CUTOUT (AT 50% N2) BUT PRIOR TO THE ENG REACHING STABILIZED IDLE (ABOUT 62% N2) MAY, IN SOME CASES, CREATE CONDITIONS THAT THE FUEL CONTROL CANNOT HANDLE. IN THE FUTURE, IT IS MY FIRM INTENTION TO NOT ALLOW COMPLETION OF THE AFTER START CHKLIST TO INTERFERE WITH CLOSER MONITORING OF ENG INSTRUMENTS UNTIL STABILIZED IDLE.

Data retrieved from NASA's ASRS site as of August 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.