What happened
On October 29, 2024, a Beech 58, registration N811PB, crashed near Arlberg, Arkansas, resulting in one fatality. The flight was being operated as a private, non-commercial flight under Part 91 regulations.
Earlier that morning, the pilot had flown the aircraft from Corinth, Mississippi, to Fayetteville, Arkansas, to address an intermittent autopilot issue. During an inspection at an avionics shop, a technician discovered a frayed portion of the "nose up" pitch trim cable. The technician advised the pilot that the cable required replacement, expressing concern that it could fail during flight. However, the pilot elected to fly the aircraft to his homebase in Mississippi without performing the repair.
To mitigate the risk of cable failure, the technician installed a single strand of 0.041-inch safety wire to "bridge" the frayed section of the cable. The technician also pulled and collared the autopilot and pitch trim circuit breakers, instructing the pilot not to use the manual pitch trim.
At 13:55, the aircraft departed Drake Field Airport (FYV). During the flight, the pilot contacted air traffic control at 14:22, stating, "we're having trim issues," and requested an airport with a 5,000-foot runway. At 14:24, the pilot declared an emergency, stating that the crew was using all available energy to overcome the trim forces. The final ADS-B data recorded the aircraft descending at 1,800 feet per minute into trees at 14:26.
The investigation
Post-accident examination of the wreckage confirmed that the autopilot and pitch trim circuit breakers were found pulled-and-collared. The investigation revealed three separations in the pitch trim cables: one aft of the pitch trim servo and two at the horizontal stabilizer forward spar.
The nose-up pitch trim cable was found with the safety wire attached to the turnbuckles forward of the pitch trim servo. While the technician stated the wire was intended to bridge the frayed section, the investigation found the safety wire was actually attached to both the nose-up and nose-down pitch trim cables. This configuration would have prevented the use of nose-up trim positions and allowed the trim to move between full-nose-down and the point where the safety wire became taut.