Accident Overview
On July 26, 2019, at approximately 1920 Pacific daylight time, a Cessna 177RG airplane, registration N1828Q, was substantially damaged when it nosed over during a forced landing in an open field near Fall City, Washington. The pilot and passenger sustained minor injuries. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Pilot Account
According to the pilot, as he approached his intended level-off altitude, the engine began to run rough. He decided to return to the departure airport. However, during the return flight, the engine continued to run rough and lost power. The pilot then opted to land at the nearest airport, Fall City Airport (1WA6). He reported difficulty locating the airport while on a straight-in approach. Subsequently, he misjudged the airplane's altitude and speed for landing and initiated a go-around. During the go-around, the engine lost additional power, prompting a forced landing in an open field. Due to uneven terrain, the airplane nosed over during the landing roll and came to rest inverted.
Postaccident Examination
A postaccident examination revealed that the engine could be safely run. An engine test run was conducted, and the engine operated roughly at various power settings. After the test run, the No. 3 cylinder was found to be cold to the touch, indicating it was non-operational. The No. 3 cylinder was removed for examination. Inspection of the combustion area showed that the intake valve head had a cup shape consistent with a "tuliped" valve, indicative of exposure to excessive temperatures. The softening of the valve head material due to high temperatures caused deformation into a tulip shape. This deformation prevented the intake valve from seating properly, leaving a noticeable gap through which gases and air could escape.