Aviation Accident Summaries

Aviation Accident Summary DEN08FA141

Georgia Pass, CO, USA

Aircraft #1

N487TC

CESSNA 182T

Analysis

The instrument-rated pilot was traveling cross-country with three passengers after a family vacation. The airplane was instrument-flight-rules equipped and the pilot was familiar with the airplane. There was no evidence the pilot obtained a weather briefing prior to departure and he did not file a flight plan. An analysis conducted by an NTSB meteorology specialist determined that, at the time of departure, weather was marginal visual meteorological conditions with an overcast layer above and scattered clouds at and below the flown flight level. Weather near the accident site deteriorated rapidly after departure and the pilot likely encountered a level 2 thunderstorm, lost control of the airplane and impacted terrain, destroying the airplane. Postaccident inspection of the airplane did not disclose evidence of any preimpact anomaly of the engine or airplane systems.

Factual Information

HISTORY OF FLIGHT On Friday, August 15, 2008, about 0915 mountain daylight time (MDT), a Cessna 182T airplane, N487TC, was destroyed when it impacted terrain on Mount Guyot near Georgia Pass in Park County, Colorado. The instrument rated private pilot and three passengers were fatally injured. The personal flight was being conducted under the provisions of Title 14 Code of Federal Regulations Part 91 without a flight plan. Instrument meteorological conditions prevailed at the time of the accident. The cross-country flight originated at Bob Adams Airport (SBS), Steamboat Springs, Colorado, with an intended destination of Brenham Municipal Airport (11R), Brenham, Texas. The pilot and three passengers were returning home after a family vacation. The airplane appeared on radar at 0844 and 9,200 feet mean sea level (MSL), six miles south of SBS. The airplane's path displayed a steady climb then leveled off at approximately 11,200' MSL. The radar flight path followed Victor Airway 421 southeasterly, crossed the Kremmling VORTAC, and began following Victor Airway 328 (heading 125 degrees) at 11,200' MSL. The minimum published safe en route altitude for Victor Airway 328 is 16,500' MSL. The last radar contact was at 0902 and 11,200' MSL, 30 miles southeast of the Kremmling VOR. The accident site was located 30 miles southeast of the last radar contact and five miles southwest of Victor Airway 328. A witness, who was at home 6.6 miles northwest of the accident site, heard a low flying airplane the morning of August 15th. She indicated the airplane was flying very low to the east of her home, heading south, between 0830 and 0915. She looked outside, but did not see the airplane. She thought the plane was flying in the Swan River Valley and was within 300 yards of her home. She indicated the plane's engine sounded good. Weather at her house then was cloudy, without rain. She indicated it started to rain between 0930 and 1030 and that she saw smoke coming from Mt. Guyot around 1030, but did not think much of it at the time. There was no evidence the pilot obtained a weather briefing prior to departure or filed a flight plan. PERSONNEL INFORMATION The pilot held a private pilot certificate with ratings for airplane single-engine land, airplane multi-engine land, and instrument airplane. His last Federal Aviation Administration (FAA) third-class medical was issued on August 22, 2007, with no limitations. An examination of the pilot's logbook recovered at the accident site indicated a total flight time of 1,576 hours, 154 actual instrument hours, and 39.7 simulated instrument hours, as of the last entry on June 22, 2007. Airplane rental records indicate the pilot had accumulated 71.1 hours in the accident airplane between February, 2006, and August 8, 2008, 46.7 hours of which were between August 16, 2007, and August 8, 2008. His last noted flight review was an instrument check-ride completed May 13, 2008, in the accident airplane. AIRCRAFT INFORMATION The 2004-model Cessna 182T, serial number 18281486, was a high wing airplane with a fixed, tri-cycle landing gear, and was configured for four occupants. The airplane was powered by a direct drive, horizontally opposed, fuel injected, air-cooled, six-cylinder engine. The engine was a Lycoming AEIO-540 SER, serial number L-29918-48A, rated at 230 horsepower at 2,400 rpm, and was driving a three-bladed, controllable pitch, metal McCauley propeller. According to the airframe logbook, the airplane's most recent annual inspection was completed February 8, 2008, and the most recent 100 hour inspection was completed on June 24, 2008, with an airframe total time of 1,492.4 hours. The engine logbook revealed that the engine had been inspected in accordance with an annual inspection on February 8, 2008 and a 100 hour inspection was completed June 24, 2008. The airplane was equipped with a Garmin G1000 avionics suite, XM satellite weather down link and Stormscope. METEOROLOGICAL INFORMATION Upper air analysis indicated an upper low over Wyoming during the morning of August 15. Easterly, upslope flow advected abundant moisture and scattered rain to the front range of the Colorado Rockies. In addition, upper level instability and abundant low- and mid-level moisture over the central Colorado Rockies produced scattered rain and snow showers over the higher elevations. Isolated embedded thunderstorms were also occasionally present. The morning Weather Depiction and Radar Summary charts indicated marginal VFR and IFR conditions with scattered light rain/snow showers over the northern half of Colorado. The Radar Summary chart showed isolated thunderstorms over the central part of the state. Weather observations from Yampa Valley (KHDN) and Mount Werner (K3MW) indicated multiple cloud layers in the area surrounding Steamboat Springs. Cloud base layers were indicated at about 12,600 feet and 18,600 feet MSL in the area. Visible satellite image showed probable breaks in the cloud layers in the vicinity of SBS at 0845. Weather observations from Kremmling AWOS (K20V) and Red Cliff Pass (KCCU) indicated a broken-overcast layer between 16,000 and 17,000 feet MSL. Scattered clouds were reported below the primary layer. Infrared and visible satellite imagery showed an overcast cloud condition between SBS and an area northeast of KCCU. Maximum cloud tops of the broken-overcast layer were approximately 19,000 feet MSL. The visible data indicated an area of scattered to broken clouds from northeast of KCCU to near the accident site. Visible satellite images for 0845 and 0915 showed that clouds in the accident area increased in areal and vertical extent during the 30-minute period. The lumpy appearance of the clouds just east of the accident location was consistent with convective cloud formation. Enhanced infrared satellite images for the same times confirmed that cloud tops near the accident site cooled during the 30-minute period. Cloud-top temperatures indicated a cloud-top between 21,000 feet and 30,000 feet MSL and weather radar data indicated level 1 and level 2 returns in the vicinity of the accident location. AIRMETs for instrument meteorological conditions and mountain obscuration were valid for the accident time. WRECKAGE AND IMPACT INFORMATION The wreckage was located on the southeast side of Mount Guyot, near Georgia Pass in Park County, at approximately 12,300 feet MSL. Terrain was open and rocky above the vegetative tree line and sloped 35 degrees. There was one impact point located 20 feet uphill of the main wreckage, indicated by scarring on rocks, disturbed soil and discolored foliage. Airplane damage and impact site disruption indicated the airplane was approximately 55 degrees nose low, wings level, and heading 295 degrees when it impacted terrain. The fuselage lay below the point of impact 20 feet on a heading of 200 degrees. The cockpit, wing center section, and the inboard section of both wing fuel tank areas were consumed by fire; including the instrument panel and switches. The right wing laid nearly parallel to the fuselage on the right side near the empennage and the left wing lay nearly parallel to the fuselage near the engine on the left side. The leading edges of both wings showed aft accordion crushing. Flight control cable continuity was confirmed for all flight controls. The left wing aileron and flap cables separated at the wing root with tension overload signatures. The elevator trim tab actuator measurement equated to approximately five degrees tab up. Flap actuator measurements indicate the flaps were retracted. One propeller blade was found separated from the hub near the initial impact point and the other two remained attached to the hub. The free blade had cord wise scratching and a chunk missing from the leading edge near the tip. One of the attached blades had the tip melted and curled aft, and the second had cord wise scratches. A propeller strike ground scar was noted at the initial impact location. The engine examination revealed the left magneto was knocked off and mostly consumed by fire. The right magneto was found heat damaged. The drive was rotated and no spark was observed. The fuel pump was broken free from the flange and the body was mostly consumed by fire. The fuel servo was found broken free from the sump. The throttle cable was found broken at the rod end, and the mixture cable remained attached. The regulator cover brass hex plug was found tight and safety wired. The fuel servo screen was found free of debris, along with the fuel injectors. The fuel flow divider was examined and no anomalies noted. The cylinders were Borescope inspected and no anomalies were noted. The crankshaft was rotated by hand and thumb compression was noted at all cylinders, and engine drive train continuity was established throughout. The oil pickup screen was removed and found free of debris along with the propeller governor screen. The spark plugs appeared normal as compared to the Champion Aviation Check a Plug Chart AV-27 except for the presence of oil on numbers 2, 4, and 6. The engine was found upside down and left side low at the accident site. A hole was observed knocked in, near the center bottom of the oil sump. The exhaust was found mostly intact but crushed upward and to the rear. The vacuum pump was examined, and revealed a cracked rotor with the vanes intact. The drive coupler was found melted. There was no evidence found of a catastrophic in-flight engine failure or power loss. MEDICAL AND PATHOLOGICAL INFORMATION The Office of the Medical Examiner of Jefferson County, located in Golden, Colorado, performed an autopsy on the pilot on August 19, 2008. The cause of death was attributed to massive bodily injury secondary to blunt force trauma. The FAA, Toxicology Accident Research Laboratory, located in Oklahoma City, Oklahoma, conducted toxicological testing on the pilot. The pilot tested negative for carbon monoxide and Cyanide. The pilot tested positive for Ibuprofen in his blood.

Probable Cause and Findings

The pilot's failure to maintain aircraft control after inadvertantly encountering instrument meteorological conditions. Contributing to the accident were the pilot's failure to obtain a weather brief and the severe weather conditions.

 

Source: NTSB Aviation Accident Database

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