ERA22LA310

The pilot, who was also a mechanic, purchased the airplane after it had been involved in an accident. The pilot completed major repairs and a conditional inspection on the airplane and planned to complete the first test flight from a soybean farm field near his residence. He taxied the airplane to the field and completed a normal run-up. He then operated the electric horizontal stabilizer trim, via the rocker switch on the control stick, to the takeoff position (full nose up) as indicated on the primary flight display (PFD). When the trim indicator reached the takeoff position, he removed his thumb from the trim switch and initiated the takeoff roll. The airplane accelerated normally, and he moved the control stick aft to rotate however, a heavy nose down pressure was felt. He immediately aborted the takeoff and, in his effort to slow the airplane, it nosed over. The left wing and empennage sustained substantial damage. Examination of the horizontal stabilizer trim position found that it was set to a full nose down position, as observed at the control surface and on the PFD trim indication. Examination of the trim rocker switch found that it would operate the trim actuator; however, when the switch was released, it would not return to the neutral position as designed. In order to stop the trim movement from continuing to run until it reached its maximum nose up/down limit, the switch was required to be moved to the center position, which would stop the trim movement. It is likely that the stabilizer trim continued to operate towards the nose down position during the takeoff roll, after the pilot had released his thumb from the switch, which resulted in the pilot feeling a heavy nose down force during the takeoff. There was no evidence that the pilot/mechanic evaluated the rocker switch’s proper operation during the major repairs and recent conditional inspection. Had he inspected the switch for proper movement, it is likely that he would have detected the faulty condition of the switch, and the accident likely would have been prevented.

On July 3, 2022, about 0930 eastern daylight time, a Cub Crafters CC11 160 airplane, N55JV, was substantially damaged when it was involved in an accident near Findlay, Ohio. The commercial pilot was not injured. The airplane was operated by the pilot as a flight test conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The pilot reported that the airplane was involved in an accident in 2020 (in which he was not the pilot). He purchased the airplane and made extensive repairs to return it to an airworthy condition. This accident flight was the first test flight since the previous accident. The pilot taxied from his property to an adjacent off-airport soybean farm field and performed a run-up without issue. He then operated the electric horizontal stabilizer trim via the rocker switch on the control stick, to the “nose up position” as indicated on the primary flight display (PFD). He then moved the trim back in a nose down direction towards the neutral takeoff position. When the trim indicator reached the takeoff position, he removed his thumb from the trim switch and initiated the takeoff roll. The airplane accelerated normally, and he moved the control stick aft to rotate; however, he felt a “very heavy” nose down pressure on the control stick. He immediately aborted the takeoff and, in his effort to slow the airplane, it nosed over. The left wing and empennage sustained substantial damage. A Federal Aviation Administration (FAA) inspector examined the airplane after it was moved from the accident site. The horizontal stabilizer trim position found at the flight control surface and as indicated on the PFD was consistent with a full nose down setting. The pilot reported that shortly after the accident he observed this trim setting as well. Examination and tests of the trim rocker switch found that it would move the horizontal stabilizer; however, when the switch was released, it would not return to the neutral position as designed. In order to stop the trim movement, the switch needed to be moved to the center position, or else it would continue until the maximum nose up/down limit was reached. The airplane’s operating manual described that pitch trim was accomplished via an electric servo which moved the leading edge of the horizontal stabilizer up and down, changing the angle of incidence. The servo was actuated with a rocker switch located on the control stick. Review of maintenance records found that the accident pilot was the mechanic who completed the major repair and alteration and the most recent conditional inspection. The repairs were completed and signed off on June 27, 2022. According to the FAA inspector who interviewed the mechanic/pilot, he was unable to provide evidence or indication that the trim switch had been inspected for proper operation during the most recent repairs or preflight prior to the flight test. The airplane was involved in an accident on September 18, 2020 (National TransportationSafety Board investigation identification number CEN20CA404). The trim system was not reported as a factor in the accident.