Accident Overview
On March 12, 2019, at 1442 central daylight time, a Piper PA32R-300 airplane, registration N750R, was substantially damaged during a forced landing following a loss of engine power near Waterloo, Illinois. The pilot sustained serious injuries, one passenger sustained minor injuries, and a second passenger, a child restrained in a car seat, was not injured. The flight was conducted by the pilot under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Pilot Report
The pilot reported hearing a "horrible noise" and the engine "immediately seized" about 10 minutes from the destination airport. Oil covered the windshield, obstructing his forward field of view. He executed a forced landing to a road by holding the airplane in a right crab to see out of the left side window. The airplane came to rest inverted in a grass area adjacent to the road, with damage to the fuselage and both wings.
Engine Examination
A postrecovery engine examination revealed that the No. 4 and No. 6 connecting rods had separated from the crankshaft. The No. 4 connecting rod was fractured through the upper rod yoke, with the corresponding rod cap and bearing fragments deformed. The No. 6 connecting rod was fractured across one side of the rod yoke; the opposite side was intact but deformed, and the corresponding rod cap was deformed. The connecting rods remained attached to the pistons, which were wedged within the cylinders. The pistons, lower cylinder flanges, and connecting rods exhibited secondary mechanical damage. The crankshaft was intact. The crankcase was fractured above the No. 4 and No. 6 cylinders, exposing a hole in the upper surface of the crankcase.
Metallurgical Findings
Metallurgical examination was unable to determine the source of the initial failure due to secondary mechanical damage. The intact fracture surfaces that were available for examination exhibited features consistent with overstress.