On October 2, 2025, about 1050 Pacific daylight time, a Siai-Marchetti SM 1019, N3172U, sustained substantial damage when it was involved in an accident near Richland, Washington. The pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he departed Tri-Cities Airport (PSC), Pasco, Washington, on a local flight. About 45 minutes into the flight, he observed uncommanded engine rpm oscillations and decided to make a precautionary landing at Richland Airport (RLD), Richland, Washington. While on the downwind leg for runway 19, as the pilot moved the condition lever forward, it felt like the propeller was moving unsolicited, from beta to flight idle. He recalled that when he tried to return the propeller from beta to flight idle, the engine rpm oscillations increased significantly. As the pilot turned onto final for runway 19, he noticed that the engine rpm oscillations became more erratic. The pilot stated that when the propeller felt like it had entered beta, the airspeed decreased below the airplane’s stall speed and thrusted the occupants forward in their seats. Subsequently, the pilot lowered the nose, added power, and noted that the slightest increase of the power control lever resulted in an extreme engine rpm increase followed by the nose of the airplane pitching upward. He applied 15° flaps and slowed the airplane to about 50 knots. The pilot stated that after touchdown, the landing roll was normal for about 50 ft. As he applied brakes, the engine rpm increased and the airplane became airborne. Subsequently, the airplane turned left, touched down hard on the runway, and the right main landing gear collapsed. Subsequently, the airplane exited the left side of the runway and came to rest upright. Postaccident examination of the airplane revealed that the right wing was substantially damaged. The airplane was recovered to a secure location for further examination.