What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The pilot made a fuel stop in Lagrange, GA where the lineman fueled both wings tanks to the full mark in the filler neck. The lineman failed to properly reinstall the right fuel tank cap. The pilot did not physically check the cap on preflight and during takeoff the cap came out of the filler neck. Approximately eleven gallons of fuel vented out of the tank and over the top of the wing. The pilot returned to Lagrange and taxied to the ramp. Both engines were shut down and the cap was properly installed. After approximately ten minutes the pilot initiated a normal hot engine start of the left engine. During initiation start of the right engine a back fire occurred and the right wing ignited/exploded. The pilot continued turning the engine and the fire extinguished. The lineman saw a small flame remaining and sprayed the area with a fire extinguisher. The right wing box area from the engine pylon out to the wing tip experienced rapid internal expansion and bulged the wing skin. The right aileron experienced internal rapid expansion and also bulged the aileron skin.
As the FAA filed it
THE PILOT MADE A FUEL STOP IN LAGRANGE, GA WHERE THE LINEMAN FUELED BOTH WINGS TANKS TO THE FULL MARK IN THE FILLER NECK. THE LINEMAN FAILED TO PROPERLY REINSTALL THE RIGHT FUEL TANK CAP. THE PILOT DID NOT PHYSICALLY CHECK THE CAP ON PREFLIGHT AND DURING TAKEOFF THE CAP CAME OUT OF THE FILLER NECK. APPROXIMATELY ELEVEN GALLONS OF FUEL VENTED OUT OF THE TANK AND OVER THE TOP OF THE WING. THE PILOT RETURNED TO LAGRANGE AND TAXIED TO THE RAMP. BOTH ENGINES WERE SHUT DOWN AND THE CAP WAS PROPERLY INSTALLED. AFTER APPROXIMATELY TEN MINUTES THE PILOT INITIATED A NORMAL HOT ENGINE START OF THE LEFT ENGINE. DURING INITIATION START OF THE RIGHT ENGINE A BACK FIRE OCCURRED AND THE RIGHT WING IGNITED/EXPLODED. THE PILOT CONTINUED TURNING THE ENGINE AND THE FIRE EXTINGUISHED. THE LINEMAN SAW A SMALL FLAME REMAINING AND SPRAYED THE AREA WITH A FIRE EXTINGUISHER. THE RIGHT WING BOX AREA FROM THE ENGINE PYLON OUT TO THE WING TIP EXPERIENCED RAPID INTERNAL EXPANSION AND BULGED THE WING SKIN. THE RIGHT AILERON EXPERIENCED INTERNAL RAPID EXPANSION AND ALSO BULGED THE AILERON SKIN.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.