Incident Description
After landing on runway 17L, the aircraft turned onto taxiway 'L.' The left wing then caught fire. Crash, Fire, Rescue (CFR) personnel responded and extinguished the fire. The pilot reported to the FAA that after turning onto the taxiway, he heard a 'bang.' He attempted to turn the airplane to inspect the taxiway but observed smoke. He stopped the airplane, shut off the engines, and all occupants evacuated through the right door.
Post-Fire Examination
Examination of the left wing revealed soot in the wing bay outboard of the auxiliary fuel cell. Soot was also found on the stall warning switch near an unused open terminal. Fuel stains were present on the bottom of the fuel cell bay liner and on the lower wing skin in the fuel cell area. The wing access panel, located outboard of the APU plug receptacle in the engine exhaust trail area, was found unsealed. Similarly, the flap bell crank bolt access panel, also in the engine exhaust trail area, was not sealed.
The battery positive cable was an automotive-type cable, with the relay end melted. The battery ground lead had numerous broken wire strands at the battery end terminal.
Investigation Findings
The fuel pump resistor and wire bundle from the left wing were sent to the NTSB Materials Laboratory in Washington, D.C., for examination to determine if they were the ignition source. The wires were sooted and displayed heat damage consistent with exposure to a fire. Most of the insulation on individual wires was missing, exposing the conductors. Where insulation remained, it varied from slightly sooted to completely charred and crumbling. Inspection of individual wires under a stereo microscope revealed that the copper conductors were heat damaged but remained intact. No indication of arcing or electrical shorting was found on the wire surfaces. No determination of an ignition source for the ground fire was made.