Initial Incident
On September 4, 2024, at about 1950 central daylight time, a Piper PA-28R-200 airplane, registration N4081S, sustained substantial damage during an accident near Crystal, Minnesota. The pilot, who was the sole occupant, was uninjured. The flight was conducted under 14 CFR Part 91 as a personal flight.
The pilot performed a preflight inspection with no anomalies. After departure from Crystal Airport (MIC), the pilot completed a local area flight and returned to MIC. During the landing flare, the airplane encountered a gust of wind, climbed about 3 feet, and landed on the runway centerline. The pilot described the landing as firm but not hard. The airplane was refueled and returned to the hangar without further issues.
Subsequent Flights
The following day, the pilot's son flew the airplane. After a preflight inspection with no anomalies, he took off and retracted the landing gear. The "gear in transit" light remained illuminated. He extended the landing gear, and all three green landing gear lights illuminated. He landed back at MIC and taxied to the hangar without incident.
The next day, the pilot's son flew the airplane from MIC to Rochester International Airport (RST) in Rochester, Minnesota, for a mechanic inspection. The landing gear remained extended for the entire flight. After landing and taxiing at RST without incident, a post-flight inspection by the mechanic revealed a fractured engine mount at the nose gear attachment point.
The engine mount, Piper part number 67119-57, sustained substantial damage and was not serialized.
Postaccident Examination
Examination of the engine mount fracture surface showed substantial damage from oxidation and post-fracture contact. Greasy deposits covered the black painted surfaces on most of the fractured tube's exterior. Inside the tube, an accumulation of greasy, black deposits of corrosion products and debris was observed. Areas with relatively flat features perpendicular to the tube axis were seen in several locations, mostly on the left half of the fracture. Radial lines and ratchet marks emanated from the interior edge, consistent with fatigue initiating from corrosion pits at the interior surface. Each fatigue region had multiple origins.
The fatigue regions extended through the wall thickness on the aft left and forward left portions of the fracture. On the forward right side, the fatigue region extended part way through the thickness. An area on the left side was smeared from post-fracture damage, so the fracture mechanism was undetermined there. The remainder of the fracture surface outside the fatigue boundary and to the right had rough features on slant angles consistent with ductile overstress fracture.
At the time of the accident, the airframe, manufactured in 1974, had accumulated 3,711 hours. The most recent annual inspection was completed on November 8, 2023.