At about 0707 Central time, the airplane experienced an outboard left wing fire during the takeoff roll. Visual conditions prevailed; the pilot reported no injuries. The airplane was substantially damaged. During the takeoff roll, at about 50 knots, the pilot heard an “explosion” and could feel a thud in the rudder pedals (like he had hit a runway centerline light). He saw damage on the left wing with black smoke coming out a hole in the wing. The pilot stopped the airplane, exited and put out the fire with the onboard fire extinguisher. About 37 inches of the outboard left wing and wing tip remained attached, but exhibited compression buckling and fire damage. The upper wing skin panel, located inboard of the wingtip, was bent upward. The outboard leading edge fuel cell was removed to facilitate a leak check. The fuel cell was pressurized and an air leak was found on the aft side of the fuel cap assembly, at the interior fuel placard mounting rivets. No visible fuel leaks or staining was observed around the vents or sump drains of the airplane. The fuel pump or fuel strainer did not exhibit any leaks or staining.
