CESSNA 182F

Full Narrative

On April 28, 2018, about 1715 mountain daylight time, a Cessna 182F, N3377U, was substantially damaged when it was involved in an accident near Boulder, Utah. The private pilot sustained a minor injury, while his two passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot departed on a 172-nautical (nm) mile cross-country flight. Upon arriving in the area of the destination, they were circling over the town when the pilot observed a high exhaust gas temperature (EGT) indication. He stated that, at this time he enriched the fuel mixture setting to full rich, leveled off to cool the engine down, and immediately began looking for a possible emergency landing site. When he realized that the airplane could not maintain altitude, as engine power was decreasing, he chose a grassy field for a forced landing. During the landing roll, the airplane collided with a ditch, which separated the nose landing gear. The pilot reported that he then applied the brakes, but collided with a second ditch, which brought the airplane to a stop partially on its nose at about a 20° tail-high angle. The airplane came to rest on a magnetic heading of about 111° at an elevation of 6,627 ft mean sea level (msl), and sustained substantial damage to its firewall and engine mounts.

The airplane was examined after recovery from the site. Both wings had been separated from the fuselage for purposes of recovery. All four engine mounts were broken, and the engine was pushed aft.

The lower cowling, lower exhaust tubing, and cowl flap were impact damaged. The position of the cowl flap could not be determined. The propeller governor control and the carburetor heat cables were impact damaged and could not be functionally tested. The oil cooler coils were unremarkable.

Electrical continuity of the cylinder head temperature/exhaust gas temperature/outside air temperature gauges was confirmed. The mixture control cable and the throttle cable remained connected and moved freely and correctly. The fuel selector valve was free to rotate when activated by hand; each detent was defined.

The upper spark plugs and valve covers were removed. The engine was rotated at the propeller flange, with no binding noted through the valve train to the accessory section. Valve movement was noted on all cylinders, and thumb compression was detected on all cylinders. Spark was noted on the upper p-leads. 

The upper spark plugs exhibited signatures consistent with a lean mixture and worn-out condition when compared to a Champion Spark Plug Check-a-Plug chart. The lower spark plugs were also removed and exhibited signatures consistent with normal to worn-out condition.

Examination revealed no evidence of anomalies that would have precluded normal operation.
The 1653 weather observation at Bryce Canyon Airport (BCE), Bryce Canyon, Utah, located about 60 nm west of the accident site, reported temperature 21°C, dew point 13°C, and an altimeter setting of 29.95 inches of mercury. Based on these conditions, the computed density altitude at the time of the accident was 8,814 ft msl.