Accident Overview
On July 27, 2022, at approximately 1725 Alaska daylight time, a Cessna 207A (registration N6908M) sustained substantial damage during an accident near Dillingham, Alaska. The aircraft was operating as a Title 14 Code of Federal Regulations Part 135 scheduled flight. The pilot and two passengers were uninjured.
Events During Flight
During the approach to landing, the pilot noticed that the left rudder pedal was unresponsive. A emergency was declared, and the pilot succeeded in landing the airplane without further incident.
Post-Accident Examination
A Federal Aviation Administration inspector examined the aircraft and discovered that one of the rudder cables had fractured. Rust was visible at the fracture location. The cable failure adversely affected the aircraft's performance and flight characteristics, necessitating cable replacement, which constituted substantial damage.
Further examination revealed the rudder cable had fractured approximately 94 inches from the turnbuckle terminal end and 152 inches from the center of the attachment holes in the clevis at the opposite end. The pulleys' bearings moved freely, but the left pulley exhibited abrasion on its outer rim and orange deposits consistent with rust in the groove, along with rubbing around much of the groove contact surface. The right pulley showed no rubbing damage, but the cable contact pattern was offset from the groove centerline. The fractured cable ends were mostly worn to tapered ends with no discernible fracture features, consistent with ductile overstress fracture.
Maintenance History
Review of maintenance logs indicated that the last inspection of the flight controls occurred on November 23, 2021, at an aircraft total time of 40,516.8 hours, about eight months before the accident. A maintenance entry on January 5, 2022, at 40,536.6 hours noted a "left hand rudder stuck pulley at the aft baggage bulkhead" and "corrosion of the L/H rudder cable at aft baggage bulkhead." The mechanic's response stated that upon further inspection, the cable was determined not corroded, and no defects were found. At the time of the accident, the aircraft had accrued 40,885 total hours.