Aviation Accident Summaries

Aviation Accident Summary DEN02LA033

Fruitland, UT, USA

Aircraft #1

N66076

Cessna 172Q

Analysis

The pilot purchased 36 gallons of avgas at 1813 and departed the airport approximately 1830. Approximately 1850, while in cruise flight, the engine "sputtered and ran rough then quit." During descent, severe turbulence was encountered and the airplane possibly entered a spin. The pilot sighted a clearing and made a forced landing in deep snow and at night. There was no odor of fuel or fuel stains at the accident site. When the airplane was removed from the site, about two or three gallons of fuel leaked onto the floor of the trailer. At the salvage yard, water was used to fill both fuel tanks. Neither integral fuel tank was breached. The fuel vent lines, check valve, fuel selector valve, fuel supply lines, and auxiliary fuel pump were unremarkable. The gascolator was not damaged and contained no fuel. The fuel screen was clean and free of debris. There were no fuel stains anywhere on the airframe. About two ounces residual fuel were drained from the carburetor. According to the engine manufacturer's investigator, "the spark plugs and exhaust system gas path exhibited dark black coloration consistent with engine operation at rich fuel/air mixture operation." Weather recorded at a remote station near the accident site was as follows: temperature, 23 degrees F.; dew point, 16 degrees F.; relative humidity, 74%; wind, 070 degrees at 6 miles per hour, gusting to 10 miles per hour. According to the "Icing Probability Chart," conditions were conducive for the formation of carburetor ice in glide and cruise power configurations.

Factual Information

On March 15, 2002, approximately 1850 mountain standard time, a Cessna 172Q, N66076, registered to EDB Air, Inc., and operated by Wings of Denver, Englewood, Colorado, was destroyed during a forced landing near Strawberry Reservoir, Fruitland, Utah. The private pilot and one passenger received serious injuries. Night visual meteorological conditions prevailed, and no flight plan had been filed for the personal flight being conducted under Title 14 CFR Part 91. The flight originated at Roosevelt, Utah, approximately 1830. Since the pilot could not recall details of the accident, the following is based on information provided by the passenger and other evidentiary material. They departed Centennial Airport, Englewood, Colorado, and flew to Meeker, Colorado; Duchesne, Utah, and Roosevelt, Utah, in search of fuel. According to a credit card receipt, they purchased 36 gallons of avgas at a Roosevelt self-service pump at 1813. Estimated time of departure from Roosevelt was 1830. The passenger said that they were en route to Heber City, Utah, between 10,000 and 12,000 feet msl. Approximately 1850, when the airplane was in cruise flight, the engine "sputtered and ran rough then quit." As they descended, they encountered severe turbulence and "dropped rapidly." The airplane "seemed to be in a flat spin with very high G forces...and entered a foggy cloud layer. They "departed the spin as abruptly as it started," sighted a clearing, and made a forced landing in deep snow. The passenger tried to use a shirt to collect fuel and build a fire. He could not get any fuel. Rescuers detected ELT (emergency locator transmitter) signals at 1857, and located the downed airplane with the aid of night vision goggles. The passenger was also able to assist rescuers by talking to them on his cellular telephone. According to search and rescue personnel, there was no odor of fuel or fuel stains at the accident site. Weather information at the accident site was not available. Weather recorded at Rays Valley (RVZU1), a remote automated weather station operated by the National Oceanic and Atmospheric Administration (NOAA) and located 16 miles west of the accident site, was as follows: temperature, 23 degrees F.; dew point, 16 degrees F.; relative humidity, 74%; wind, 070 degrees at 6 miles per hour, gusting to 10 miles per hour. The Heber-McDonald airport AWOS (automated weather observation station), located 27 nautical miles northwest of the accident site, reported the following: wind, 150 degrees at 2 knots; visibility, 9 statue miles; sky condition, clear; temperature, 27 degrees C.; dew point, 14 degrees C. When the airplane was recovered by a salvage company, about two or three gallons of fuel leaked from the front of the airplane while it sat on a trailer. Both wings and the fuselage were buckled. The wreckage was transported to the salvage yard where, on April 3, 2002, it was examined further. Using water to fill both fuel tanks, neither integral fuel tank was found to have been breached. Examination of the fuel vent lines, check valve, fuel selector valve, fuel supply lines, and auxiliary fuel pump disclosed no anomalies. The gascolator was not damaged and contained no fuel. The fuel screen was clean and free of debris. There were no fuel stains anywhere on the airframe. About two ounces residual fuel were drained from the carburetor. According to a report submitted by the engine manufacturer's investigator, "the spark plugs and exhaust system gas path exhibited dark black coloration consistent with engine operation at rich fuel/air mixture operation...Conditions conducive to the production of carburetor icing, possibly induction icing, existed. The incipient nature of carburetor icing may have gone unnoticed, until a large piece of ice broke loose and obstructed the airflow, resulting in a significant reduction of power." Using the RVZU1 1835 observation, the "Icing Probability Chart" indicated conditions were conducive for the formation of carburetor ice in glide and cruise power configurations.

Probable Cause and Findings

the pilot's failure to apply carburetor heat. Contributing factors included carburetor icing conditions, the unavailability of suitable terrain on which to make a forced landing, and night conditions.

 

Source: NTSB Aviation Accident Database

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