Primary finding
Probable cause
The failure of the right rudder pedal stop due to an inadequate weld, which resulted in a loss of control on the ground.
Investigator assessment
Analysis narrative
The pilot, who was in the right seat, stated the left-seat pilot had just completed three uneventful full-stop landings, and then he took over the controls and was flying from the right seat. During the takeoff roll, he applied equal pressure to both rudder pedals. Suddenly, the right pedal broke forward, and the airplane veered off the left side of the runway. The left-seat pilot was unable to assist in controlling the airplane before it struck a berm. The airplane came to rest upright with the main landing gear collapsed, which resulted in substantial damage to the right side of the fuselage and engine mounts. Postaccident examination revealed that the right seat’s right rudder pedal stop, a U-shaped metal rod welded to the rudder pedal torque tube, broke at the weld, and the right pedal was beyond the normal forward limit. The weld appeared to have inadequate penetration into the base material, which resulted in a failure of the weld that allowed the rudder pedal to extend beyond the normal forward limit.
Source record
Factual narrative
On May 31, 2023, about 0930 mountain daylight time, a Wittman W10 Tailwind airplane, N456TW, was substantially damaged when it was involved in an accident at Fremont County Airport (1V6), Penrose, Colorado. The pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated the other pilot in the left seat had just completed three uneventful full-stop landings, then he took over the controls and was flying from the right seat. During the takeoff roll, he applied equal pressure to both rudder pedals. Suddenly the right pedal broke forward and the airplane veered off the left side of the runway. The left-seat pilot was unable assist in controlling the airplane before it struck a berm. The airplane came to rest upright with the main landing gear collapsed, which resulted in substantial damage to the right side of the fuselage and engine mounts. Postaccident examination by the responding Federal Aviation Administration inspector revealed that the right rudder pedal stop, a U-shaped metal rod welded to the rudder pedal torque tube, broke at the weld bead and the right pedal was beyond the normal forward limit. The inspector reported observing no corrosion, but that there was inadequate penetration of the weld between the rudder stop and rudder pedal torque tube. Figure 1 shows the right pedal condition after the accident. Figure 1. The right side pedals after the accident. The right pedal is forward of the normal limit. The left pedal is at the normal upright position (courtesy of the pilot). According to the pilot, the airplane was scratch-built from plans and was not assembled from a kit; therefore, the rudder pedals were fabricated by the original builder. The airframe had accumulated 339.2 hours of total time. There had been no discrepancies or recent maintenance completed related to the rudder pedals.