On July 14, 2019, about 1100 central daylight time, a Cessna 177 airplane, N29516, was substantially damaged when it was involved in an accident near Elkhart, Indiana. The pilot and two passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, he placed two passengers into the airplane (a child was in the rear right seat and an adult in the front right seat) and had them secure their seatbelts. He then began a preflight, which he completed while the passengers waited in the airplane. While standing in front of the airplane’s nose and checking the tension on the propeller belt, the pilot lowered the propeller blade by “smacking it down” in a clockwise direction. The engine started, and the airplane began to move forward under its own power; the pilot jumped out of the way. The airplane proceeded toward the grass between the ramp and the taxiway, then continued over the taxiway and over the grass between the taxiway and the runway, and up over the runway where it became airborne. The airplane came back down on the other side of the runway and stopped in an adjacent wheat field. The airplane received substantial damage to the forward fuselage structure. According to the adult passenger, the pilot was standing in the front of the airplane and spun the propeller “a little” and “all of a sudden, the airplane came roaring to life.” The pilot jumped and tried to run around to get in the airplane but was unable. She tried to reach the brake pedals with her feet to stop the airplane, but she could not reach the pedals. The pilot stated the key was in the ignition but not turned to “START,” and he could not recall the configuration of the mixture and throttle during his preflight walkaround. According to an FAA inspector, the mixture and throttle were in the full forward position during the on-scene examination. The ignition key had been removed from the ignition after the accident and was sitting on the right seat, so the position of the switch at the time of the accident could not be verified. The inspector did not remove the engine cowling or examine any components within the engine compartment.