DFW06CA185 · Cessna 120

The 255-hour non-instrument rated private pilot, who reported to have accumulated 25-hours in the same make and model, reported that the tailwheel-equipped airplane drifted-off the left side of the 2,630-foot long by 30-foot wide asphalt runway during the takeoff roll on Runway 13. The pilot reported that soon after the tail came up during the takeoff roll, the airplane experienced an uncommanded "lurch" to the left, which he was unable to correct with the opposite rudder and aileron. The pilot added that as soon as the airplane entered the grassy area adjacent to the runway, he closed the throttle and held the elevator in the full aft position to keep the tailwheel on the ground. Subsequently, the pilot became aware of two drainage ditches crossing perpendicular to his intended path. The airplane had enough speed to cross the first ditch; however, the main landing gear collided with the second ditch resulting in a nose over. The airplane came to rest in the inverted position. On the recommendation block of his report, the pilot stated that there was a stand of trees on the right side of the runway, which may have caused the wind to push the airplane to the left just as the plane rolled past the tree line. The FAA inspector, who traveled to the accident site, confirmed that the airplane sustained structural damage. The inspector was able to establish flight control continuity and did not find any pre-existing mechanical malfunctions. At the time of the mishap, the winds were reported from 180 degrees at 10 knots.

Verbatim NTSB analysis and probable cause from the NTSB dataset