On January 15, 2022, about 1230 Pacific standard time, a Bell 205A-1 helicopter, N502HQ, sustained substantial damage when it was involved in an accident near El Cajon, California. The flight instructor and the pilot receiving instruction were not injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor stated that he was demonstrating an autorotation to the pilot receiving instruction as part of the company’s flight training program. The flight instructor entered the autorotation at an altitude of about 1,500 to 2,000 ft above ground level and reduced the engine’s power to flight idle during the descent. When the helicopter reached its power recovery altitude, the instructor attempted to increase the engine’s power, but the engine did not respond. Subsequently, he attempted to recover engine power three times but was unable to do so. The pilot then committed to a touchdown autorotation. On touchdown, the helicopter rocked forward and then aft on its skids, and the main rotor blades struck the tailboom, which sustained substantial damage. A postaccident examination of the engine, governor, and fuel control (which included a full engine run in accordance with the engine manufacturer’s overhaul manual, full vibration analysis with all parameters within limits. Functional test on the governor to check flow rates and reaction time moving from each parameter to another. Functional test of fuel regulator emergency solenoid, acceleration flow rates were checked, main components of the computer assembly were checked, and borescope inspection) revealed no preaccident mechanical malfunctions or failures that would have precluded normal operation.