Event Description
During the takeoff roll, the pilot heard a loud explosion and the aircraft violently yawed to the left. The aircraft veered off the runway and came to rest in a grassy area between the runway and the taxiway.
Fuel System Examination
Examination of the aircraft's fuel system revealed evidence of a preexisting fuel leak. Blue streaking and staining, consistent in color with 100 low lead aviation fuel, was noted on the ventral surfaces of the aircraft. Examination of the aircraft's fuel bladder revealed that the plastic interconnect nipple for the vent line, and the plastic interconnect nipple for the fuel return line, located at the distal end of the aircraft's fuel bladder, were fractured. Further examination of the fuel bladder revealed approximately 20 preexisting holes in the bladder's fabric.
Strobe Light System Examination
The aircraft's maintenance logbook indicated that the aircraft was equipped with a strobe light kit. Examination of the strobe light system revealed that the installation of the strobe kit was not in accordance with the manufacturer's installation instructions. Instead, the wiring harness for the strobe light was routed parallel to a stringer, between the wing ribs and the skin of the aircraft. Examination of the wiring revealed that the wire's insulation was chafed, cut, and discolored. The discoloration of the wiring was indicative of arcing.