Accident Overview
On April 28, 2018, at about 1715 mountain daylight time, a Cessna 182F, registration N3377U, was substantially damaged during an accident near Boulder, Utah. The private pilot sustained a minor injury, while the two passengers were not injured. The flight was operated as a personal flight under Title 14 Code of Federal Regulations Part 91.
Flight and Forced Landing
The pilot had departed on a 172-nautical-mile cross-country flight. Upon arrival near the destination, while circling over the town, the pilot observed a high exhaust gas temperature (EGT) indication. He enriched the fuel mixture to full rich, leveled off to cool the engine, and began searching for an emergency landing site. Realizing the airplane could not maintain altitude due to decreasing engine power, he selected a grassy field for a forced landing. During the landing roll, the airplane struck a ditch, separating the nose landing gear. The pilot applied the brakes, but the airplane then collided with a second ditch, coming to rest partially on its nose at an estimated 20° tail-high angle. The airplane stopped on a magnetic heading of about 111° at an elevation of 6,627 feet above mean sea level. The impact caused substantial damage to the firewall and engine mounts.
Examination Findings
After recovery, the airplane was examined. Both wings had been separated from the fuselage for recovery purposes. All four engine mounts were broken, and the engine was displaced aft. The lower cowling, lower exhaust tubing, and cowl flap sustained impact damage; the cowl flap position could not be determined. The propeller governor control and carburetor heat cables were impact-damaged and could not be functionally tested. The oil cooler coils appeared unremarkable. Electrical continuity of the cylinder head temperature, exhaust gas temperature, and outside air temperature gauges was confirmed. The mixture and throttle cables remained connected and moved freely. The fuel selector valve rotated freely by hand, and each detent was defined.
Upper spark plugs and valve covers were removed. The engine was rotated at the propeller flange; no binding was detected through the valve train to the accessory section. Valve movement was noted on all cylinders, and thumb compression was present on all cylinders. Spark was observed on the upper p-leads. Compared to a Champion Spark Plug Check-a-Plug chart, the upper spark plugs exhibited signatures consistent with a lean mixture and a worn-out condition. The lower spark plugs showed signatures consistent with a normal to worn-out condition. No evidence of anomalies that would have precluded normal operation was found.
Weather Conditions
The 1653 weather observation at Bryce Canyon Airport (BCE), Bryce Canyon, Utah, located about 60 nautical miles west of the accident site, reported temperature 21°C, dew point 13°C, and an altimeter setting of 29.95 inches of mercury. The computed density altitude at the time of the accident was 8,814 feet mean sea level.