# NTSB WPR18LA136: Cessna 182F, N3377U, Boulder, UT, April 28, 2018 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: April 28, 2018, 17:15 local (23:15 UTC) - Place: Boulder, UT - Coordinates: 37.904722, -111.41833 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.9047&lon=-111.4183&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Minor injuries - Injuries: 1 minor, 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 97194 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR18LA136 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97194/pdf - Page: https://openairdocs.org/ntsb/WPR18LA136 ## Probable cause A partial loss of engine power for reasons that could not be determined due to the available evidence. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Power plant](https://openairdocs.org/ntsb-findings/01057100): Aircraft › Aircraft power plant · Unknown/Not determined (probable cause); cases with it: [All aircraft, 198 cases](https://openairdocs.org/ntsb-findings/01057100/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis Following a cross-country flight, the pilot was circling in the area of the destination airport when he noticed an excessively high exhaust gas temperature (EGT) indication. He enrichened the fuel/air mixture to full rich and leveled the airplane in an attempt to "cool down" the engine, then noted that the airplane would not maintain altitude and that engine power was decreasing. The pilot performed a forced landing to a field, during which the airplane impacted two ditches, resulting in substantial damage. Examination of the airframe and the engine failed to reveal any mechanical anomalies that would have precluded normal operation and the reason for the decreased engine power could not be determined. The calculated density altitude at the time of the accident was 8,814 ft. ## Factual 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 analtimeter 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. ## Aircraft - Registration: N3377U (not matched to a registry record) - Reported make and model: CESSNA 182F (F) - Category: Airplane - Serial number: 18254777 - Year built: 1963 - Airframe hours: 2497.7 - Engines: CONT MOTOR O-470 SERIES reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 1, 2015, 12.3 hours before - Departed: SLC, Salt Lake City, UT - Destination: Boulder, UT - Equipment: Satellite tracking device, Stall warning system, Angle of attack indicator, Electronic flight bag or handheld device, Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 64; injuries: minor; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, unknown; seat: left; restraint: 3-point; flight hours: 1,454 total, 694 in this make and model, 1,318 as pilot in command, 6 in the last 90 days, 3 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 25 knots, gusting 33 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F, dew point 55 °F - Altimeter: 29.95 inHg - Observed at: BCE, 37 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20180428014889A](https://openairdocs.org/incident/20180428014889A), Apr 28, 2018: Cessna 182F, Boulder, UT, Substantial damage. The pilot experienced a partial loss of power during cruise flight. After going through the emergency checklist he chose to land in a field because the power… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.