Narrative:

Aircraft had an aborted takeoff on jan/tue/93 by the flight crew due to #1 engine failing to spool up, much past idle. Maintenance worked on engine all day and night trying to correct the problem, including changing the fuel control. I went to the aircraft jan/wed/93 morning to run the engine after some of the other guys in maintenance had gone home after working on the engine all night. One of the guys who had been working on the engine asked me to run it because he was not run qualified on that aircraft. He was hooking up nitrogen from a pressure bottle to the fuel control that our company maintenance control told him to try to get the engine to spool up. The forward and rear engine cowlings were inadvertently left open during start and the engine seemed to have flooded with fuel during start and caught fire burning the wing flap area. During start-up the cockpit indications were all normal, N1, N2 speed, egt rise, etc. After the engine spooled up to idle, I moved #1 throttle off idle stop to see if engine would accelerate -- it did not. The engine started spooling down below idle so I returned the throttle to idle. At that point other mechanic got out of the right seat and looked at #1 engine through the main entrance door. He said the engine was on fire, so I cut the fuel lever to the stop position and fired #1 fire bottle. He said it was still on fire so I fired #2 fire bottle. After he said it was still burning, I shut off all power to the aircraft and evacuate/evacuationed to assist outside. At no time had I gotten any fire warning in the cockpit prior to shutting off all power. Supplemental information from acn 232781: technique center wanted to troubleshoot it one last time. They wanted to verify the mec was bad by putting 50 pounds of air into the cdp sense fitting and to start the engine to see if it would accelerate. He fired the bottle into the engine and was still on fire. He fired the second bottle and the fire in the engine was out but the wing underpanels were still burning. At that time, 3 ground crew personnel from air carrier B had a bottle there extinguishing it. Then the fire department arrived. Callback conversation with reporter revealed the following information: the application of pressure to the fuel controller prior to spool- up caused fuel to flow into the engine prematurely. Upon start, there was a large puddle of fuel in the engine which ignited. That caused serious aircraft damage, both wing flaps had to be replaced. The fire was extinguished by some mechanics using portable extinguishers. The FAA is investigating. The pressure should not have been applied to the fuel controller until after engine spool-up and ignition. It is common to run up engines with the cowling open. The company is upset because, if the cowling had been closed, the fire warning system may have given a warning.

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Original NASA ASRS Text

Title: ENG FIRE DURING MAINT RUNUP CAUSES SERIOUS ACFT DAMAGE.

Narrative: ACFT HAD AN ABORTED TKOF ON JAN/TUE/93 BY THE FLC DUE TO #1 ENG FAILING TO SPOOL UP, MUCH PAST IDLE. MAINT WORKED ON ENG ALL DAY AND NIGHT TRYING TO CORRECT THE PROB, INCLUDING CHANGING THE FUEL CTL. I WENT TO THE ACFT JAN/WED/93 MORNING TO RUN THE ENG AFTER SOME OF THE OTHER GUYS IN MAINT HAD GONE HOME AFTER WORKING ON THE ENG ALL NIGHT. ONE OF THE GUYS WHO HAD BEEN WORKING ON THE ENG ASKED ME TO RUN IT BECAUSE HE WAS NOT RUN QUALIFIED ON THAT ACFT. HE WAS HOOKING UP NITROGEN FROM A PRESSURE BOTTLE TO THE FUEL CTL THAT OUR COMPANY MAINT CTL TOLD HIM TO TRY TO GET THE ENG TO SPOOL UP. THE FORWARD AND REAR ENG COWLINGS WERE INADVERTENTLY LEFT OPEN DURING START AND THE ENG SEEMED TO HAVE FLOODED WITH FUEL DURING START AND CAUGHT FIRE BURNING THE WING FLAP AREA. DURING START-UP THE COCKPIT INDICATIONS WERE ALL NORMAL, N1, N2 SPD, EGT RISE, ETC. AFTER THE ENG SPOOLED UP TO IDLE, I MOVED #1 THROTTLE OFF IDLE STOP TO SEE IF ENG WOULD ACCELERATE -- IT DID NOT. THE ENG STARTED SPOOLING DOWN BELOW IDLE SO I RETURNED THE THROTTLE TO IDLE. AT THAT POINT OTHER MECH GOT OUT OF THE R SEAT AND LOOKED AT #1 ENG THROUGH THE MAIN ENTRANCE DOOR. HE SAID THE ENG WAS ON FIRE, SO I CUT THE FUEL LEVER TO THE STOP POS AND FIRED #1 FIRE BOTTLE. HE SAID IT WAS STILL ON FIRE SO I FIRED #2 FIRE BOTTLE. AFTER HE SAID IT WAS STILL BURNING, I SHUT OFF ALL PWR TO THE ACFT AND EVACED TO ASSIST OUTSIDE. AT NO TIME HAD I GOTTEN ANY FIRE WARNING IN THE COCKPIT PRIOR TO SHUTTING OFF ALL PWR. SUPPLEMENTAL INFO FROM ACN 232781: TECHNIQUE CTR WANTED TO TROUBLESHOOT IT ONE LAST TIME. THEY WANTED TO VERIFY THE MEC WAS BAD BY PUTTING 50 LBS OF AIR INTO THE CDP SENSE FITTING AND TO START THE ENG TO SEE IF IT WOULD ACCELERATE. HE FIRED THE BOTTLE INTO THE ENG AND WAS STILL ON FIRE. HE FIRED THE SECOND BOTTLE AND THE FIRE IN THE ENG WAS OUT BUT THE WING UNDERPANELS WERE STILL BURNING. AT THAT TIME, 3 GND CREW PERSONNEL FROM ACR B HAD A BOTTLE THERE EXTINGUISHING IT. THEN THE FIRE DEPT ARRIVED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE APPLICATION OF PRESSURE TO THE FUEL CTLR PRIOR TO SPOOL- UP CAUSED FUEL TO FLOW INTO THE ENG PREMATURELY. UPON START, THERE WAS A LARGE PUDDLE OF FUEL IN THE ENG WHICH IGNITED. THAT CAUSED SERIOUS ACFT DAMAGE, BOTH WING FLAPS HAD TO BE REPLACED. THE FIRE WAS EXTINGUISHED BY SOME MECHS USING PORTABLE EXTINGUISHERS. THE FAA IS INVESTIGATING. THE PRESSURE SHOULD NOT HAVE BEEN APPLIED TO THE FUEL CTLR UNTIL AFTER ENG SPOOL-UP AND IGNITION. IT IS COMMON TO RUN UP ENGS WITH THE COWLING OPEN. THE COMPANY IS UPSET BECAUSE, IF THE COWLING HAD BEEN CLOSED, THE FIRE WARNING SYS MAY HAVE GIVEN A WARNING.

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.