Spin Practice Accident Caused by Jammed Rudder (N24779)

Accident Overview and Wreckage Findings A certificated flight instructor and a student pilot were practicing spins at approximately 3,000 feet above ground level when they failed to recover from the maneuver. The airplane subsequently entered a nose-down spiral and impacted a field. Examination of the wreckage revealed that the rudder was jammed beyond its left travel limit. Further inspection showed that the two rudder bumpers had been installed inverted. The right-side rudder bumper had traveled over and beyond the rudder stop, locking behind it. Maintenance records for the 28-year history of the airplane did not specifically mention the rudder bumpers, although work had been performed near them on several occasions. The paint on the inverted rudder bumpers was consistent with a paint job completed about eight years before the accident. The investigation could not determine whether the rudder bumpers were inverted at the time of production or if they had been inverted during the airplane's maintenance history. ## Manufacturer Service Bulletin The airplane manufacturer issued a service bulletin about three and a half years before the accident. The bulletin provided an enhanced rudder stop, bumper, doubler, and attachment hardware designed to help prevent the rudder from overriding the stop bolt during full left or right operation. The new rudder stop was significantly larger than the original. The service bulletin had not been complied with on the accident airplane, and under 14 CFR Part 91, it was not required.