Accident Details
Probable Cause and Findings
The failure of the magnetos due to a known deficiency, which resulted in a partial loss of engine power. Contributing to the accident was maintenance personnel’s failure to comply with the applicable service bulletin.
Aircraft Information
Registered Owner (Historical)
Analysis
On February 26, 2019, about 1835 eastern standard time, a Piper PA-28-181, N2184X, was substantially damaged when it was involved in an accident near Louisville, Kentucky. The private pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 flight.
According to the pilot, after performing a preflight inspection, he taxied to the active runway for departure. He conducted an engine run-up; pretakeoff checklist and no anomalies were noted. Once he was cleared for takeoff, he advanced the throttle and began the takeoff roll. As the airplane accelerated through 60 knots and became airborne, the engine started to run "rough." He elected to land straight ahead on the remaining runway. The airplane over-ran the runway and collided with the perimeter fence.
An examination of the airplane by a Federal Aviation Administration inspector revealed that the left wing was broken away from the fuselage. The outboard section of the right wing, which included the aileron, was broken away from the wing assembly. The vertical stabilizer was also separated from the empennage.
While examining the engine, the propeller was rotated through 360° of motion and spark was noted at each of the spark leads. The left magneto was removed and two ignition wires in the distributor cap revealed evidence of arcing. One ignition lead was found detached from the insulator and the spring. The right magneto was removed and rotated and produced spark at each lead. The metal copper electrode on the right magneto distributor gear was found loose.
Slick/Champion Aerospace Service Bulletin (SB)1-15A (issued July 2, 2015, and revised November 12, 2018) indicated a potential decreased service life of Slick 4-cylinder magneto distributor gear assemblies and was based on a limited number of field reports and product returns. Typical symptoms are unusual rpm drops during magneto check, difficulty starting the engine, or rough running engines. The anomaly was observed in magnetos with a varying number of service hours. The SB called for replacing affected distributor gear assemblies that have a copper electrode with assemblies that incorporate a Monel distributor gear electrode.
The accident airplane’s engine was equipped with serial numbers 4370 and 4371 magnetos, which are in the range of affected magnetos indicated in the SB. A review of the maintenance logbooks revealed an entry dated February 29, 2016, for an "excessive rpm drop of the right magneto" during run-up. No logbook entries were noted for the repair of the magnetos or compliance with SB1-15A. The airplane received three annual inspections since the release and the revision of the SB.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# ERA19LA109