CEN09LA250

While in cruise flight, the single-engine airplane experienced a total loss of engine power. During the forced landing, the airplane's nose wheel dug into the ground and the airplane nosed over, coming to rest in an inverted position. An on-site examination revealed both wing fuel tanks contained a considerable amount of fuel. Continuity to the back of the engine was confirmed. The engine was equipped with two single (left and right) magnetos, with the left magneto having an impulse coupling. The magneto's "p-leads", were disconnected and the engine rotated by hand; electric "spark" was not observed at the ignition leads. Further examination of the magnetos disclosed that they had "open" [bad] coils; and therefore produced little, if any, ignition spark. The magnetos were manufactured in 1991, and there was no maintenance record of any overhaul/maintenance preformed on the magnetos. According to the manufacturer, the magneto's coil, points, condenser, and brushes are to inspected every 500 hours and the magneto must be overhauled when the engine is overhauled.

On April 14, 2009, approximately 1915 central daylight time, a single-engine, RV-6A airplane, N6DJ, was substantially damaged during a forced landing following a loss of engine power shortly after takeoff from the Arlington Municipal Airport (GKY), Arlington, Texas. The pilot, sole occupant, received minor injuries. The airplane was registered and operated by a private individual. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 flight. A Federal Aviation Administration (FAA) inspector who responded to the site, reported the pilot stated, that he was on a local pleasure flight when the aircraft experienced a loss of engine power. The pilot elected to conduct a force landing in a vacant field. During the forced landing, the airplane's nose wheel dug into the ground and the airplane "nosed over", coming to rest in the inverted position. On April 15, 2009 the NTSB (IIC) Investigator in Charge and a technical representative from the engine manufacturer examined the airplane on-site. The airplane was turned right side up; the fuel selector was in the left position and both wing fuel tanks contained a considerable amount of fuel. The electric fuel boost pump was found to be in working order. The bottom set of spark plugs were removed from the cylinders and the engine rotated by hand. Continuity to the back of the engine was confirmed. The engine was equipped with two single (left and right) magnetos, with the left magneto having an impulse coupling. The magneto's "p-leads", were disconnected and the engine rotated by hand; electric "spark" was not observed at the ignition leads. The magnetos were removed for further examination. The magnetos were tested under the supervision of the NTSB IIC and the engine manufacturer's representative. When placed in a bench test machine, the left magneto did not produce any ignition spark; individual components were then tested. The ignition technician stated that the magneto displayed signs that the left magneto's coil was "open" [bad]. The right magneto produced an erratic electric spark, and would stop producing spark around 1200-1500 rpm. When testing the individual components of the right magneto, the coil tested "open." The Slick magnetos, model 4370 and 4371, were manufactured in 1991; and a review of the aircraft maintenance logs did not reveal any data that the magnetos were ever overhauled/maintained. According to the Slick Magneto Maintenance and Overhaul manual, # L-1363, the magneto's coil, points, condenser, brushes, are to inspected every 500 hours and the magneto must be overhauled when the engine is overhauled.