No fatalities

18 Sep 2021: Fonville SWEARINGEN SX300 (N5SX) — Buckeye, AZ

Buckeye, AZ, United States

On 18 Sep 2021, a Fonville SWEARINGEN SX300 (registration N5SX) was involved in an aviation accident near Buckeye, AZ. No fatalities were reported. Investigators recorded the probable cause as: The total loss of engine power due to the failure of the left magneto. This summary draws on records from NTSB.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

On September 18, 2021, a Swearingen SX300 experienced an engine power loss during climb, leading to a forced landing and substantial damage near Buckeye, Arizona. The pilot sustained minor injuries; the passenger was uninjured.

Accident Details

On September 18, 2021, at about 0824 mountain daylight time, a Swearingen SX300 airplane, registration N5SX, was substantially damaged in an accident near Buckeye, Arizona. The pilot reported minor injuries, while the passenger was not injured. The flight was conducted as a personal flight under Title 14 Code of Federal Regulations Part 91.

Pilot Report

The pilot stated that the takeoff was uneventful. He leveled the airplane at 1,000 ft above ground level and set engine power to 2,500 rpm, achieving an airspeed of 180 knots. During a subsequent climb, the engine power increased to 3,200 rpm and became unresponsive to input just before losing power. The pilot initiated a forced landing, during which the airplane sustained substantial damage to the wings and fuselage.

Postaccident Examination

Examination of the engine revealed that the left magneto flange was securely clamped at the mounting pad but had detached from the magneto itself. The magneto was removed for further investigation. The three attachment screws were not recovered, and the screw holes exhibited severe elongation and deformation, affecting the mating of the magneto flange and housing.

Examination of the oil filter element found copious amounts of non-ferrous (non-magnetic) metal contamination.

Fuel and Instrument Data

The pilot reported departing with 66 gallons of fuel. The airplane was equipped with a Garmin GTN-750 GPS and a JP Instruments engine data monitor. GPS data downloaded after the accident and overlaid on Google Earth showed that the airplane climbed rapidly to a higher altitude, then began a steady descent. Just prior to 0823, the airplane was at an altitude between 1,300 and 1,500 ft mean sea level, with a groundspeed of about 220 knots. Around 0823, it climbed to just under 2,500 ft msl by 0823:12, then began descending, maneuvering near terrain and ultimately toward a small road. The GPS tracklog ended near a road; the last data point recorded a groundspeed of about 98 knots and an altitude of 1,143 ft msl.

The engine data monitor indicated 3.6 gallons of fuel were used during the flight.

Contributing factors

Magneto/distributor — Failure