On July 23, 2019, about 2040 Alaska daylight time, a Cessna 182 airplane, N3934D, sustained substantial damage when it was involved in an accident near Farewell, Alaska. The private 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, during takeoff from a river gravel bar, as the airplane climbed out of ground effect, the headwind diminished, and he felt that the engine was “lagging” and that the airplane was not climbing as expected. The airplane descended into a grove of small trees at the end of the gravel bar. The nose landing gear sheared off during impact and the airplane flipped over, sustaining damage to the left wing, right wing lift strut, vertical stabilizer, and fuselage. The pilot stated that he did not have time to attempt to restore power or secure the engine before impact. Examination of the wreckage revealed that the engine was intact and securely attached to the airframe with all fittings secure. The propeller was attached to the engine and the propeller blades were secure in the hub. Each blade exhibited span wise torsional s-bending and fractures at the outboard leading edges. Engine control continuity was established, and the magnetos functioned properly. The propeller rotated smoothly by hand. There was no debris in the fuel filter and the fuel selector moved appropriately through the detents. There were no pre-impact anomalies discovered during the examination that would have resulted in a partial loss of engine power after takeoff.