Aviation Accident Summaries

Aviation Accident Summary SEA05FA169

Cascade, ID, USA

Aircraft #1

N2082Q

Cessna 177RG

Analysis

The pilot, who was en route to an airport where he and his passengers were going to participate in a family gathering, was maneuvering the aircraft at a low altitude in mountainous terrain about four miles from the destination airport. While flying up a slope toward a saddle in a ridge, the pilot failed to maintain clearance from the forest below, and the aircraft contacted a sixty foot tall conifer tree about four feet from its top. The aircraft then impacted a number of other trees, descended into the ground, and was almost totally consumed by fire. The saddle in the ridge was approximately 300 feet higher than the accident site, and about one-third mile further along the flight track. The investigation determined that the pilot was maneuvering in an area of gusty winds while at a density altitude of over 10,000 feet.

Factual Information

HISTORY OF LFIGHT On August 12, 2005, approximately 1800 mountain daylight time, a Cessna 177RG, N2082Q, impacted a stand of mature conifer trees in mountainous terrain about four miles southwest of Cascade, Idaho. The commercial pilot and his two passengers received fatal injuries, and the aircraft, which was owned by a relative of the pilot, was destroyed by the crash and the post-impact fire. The 14 CFR Part 91 personal pleasure flight, which departed Emmett, Idaho, about one hour prior to the accident, was being operated in visual meteorological conditions. No flight plan had been filed for the intended flight to the Cascade Airport. There was no report of an ELT activation. According to family members, earlier in the day, the pilot and his two passengers took off from Blackfoot, Idaho, and flew non-stop to Emmett. In Emmett, the pilot let off one of the passengers from that flight, and that passenger drove with other family members to a family gathering in Cascade. Another individual, who came to the airport with those who were going to drive to Cascade, became the second passenger on the Emmett-to-Cascade portion of the flight. Around 1700, the pilot departed Emmett in VFR conditions, with the stated intention of flying to Cascade to meet up with the other family members that were driving there. At the time of departure, the aircraft reportedly contained approximately 25 gallons of fuel, and should have arrived in Cascade with more than 15 gallons onboard. The pilot did not file a flight plan or make contact with any FAA Air Route Traffic Control (ARTC) facility en route, and although some witnesses said that they saw a retractable gear Cessna 177 (Cardinal) do a touch-and-go landing at Cascade, and depart to the west some time between 1745 and 1800, it was unclear whether that aircraft was N2082Q. About that same time of day, an FAA Inspector, who was flying over the area en route to McCall, Idaho, noticed a Cessna 177RG performing low altitude maneuvers in a valley to the west of the southern end of Cascade Reservoir. According to that inspector, the aircraft was performing a maneuver similar to a lazy-eight, and it appeared to him that the pilot was maneuvering around a specific location on the surface. The inspector did not note the aircraft's registration number, and could not positively identify the aircraft as N2082Q. Also, around the same time of day, a relative of the pilot, who was at a cabin on a small lake within two miles of the accident site, reported seeing N2082Q pass over that location. At 1810, a fire lookout station spotted a fire in an area about four miles southwest of Cascade, Idaho, and at 1940 a fire crew arrived at that location. During their attempts to get the fire under control, members of the fire crew discovered the wreckage of N2082Q. WRECKAGE AND IMPACT INFORMATON The primary wreckage had come to rest on the west side of a ridge running generally north-to-south. The accident site was located at 7,400 feet above sea level (msl), and the wreckage track ran on an up-slope magnetic heading of 010 degrees (026 true). The impact track was heading toward a saddle in the ridge that was approximately 300 feet higher than the accident site (7,700 feet). The low point in the saddle was about one-quarter to one-half mile beyond the impact site, and just beyond the saddle the terrain dropped off rapidly to the East. The initial impact point was about four feet from the top of a tree measuring approximately 60 feet in height. The four-foot section of the treetop that was sheared off by the impact was two inches in diameter at the point where it had broken. Approximately 70 feet passed the first tree, the aircraft impacted the trunk of a 75 foot-high tree, about 25 feet from its top. The trunk of that tree, which was about 12 to 18 inches in diameter at the point of impact, did not break, but a number of branches were torn off, and the trunk itself suffered impact scaring. Approximately 50 feet past the second tree impact, the aircraft collided with four other smaller trees, all of which had trunk diameters of about six to eight inches at the impact height of 15 feet above the ground. Portions of the left wing were found near the first two impacted trees, and the severely deformed rudder was found about 15 feet past the four smaller trees, but the majority of the airframe came to rest approximately 175 feet past the point of initial impact. The fuselage and the remainder of the left wing had been almost completely consumed by fire, and the inboard one-half of the right wing was severely damaged by the flames. The tip of the right wing had been torn away, and the leading edge of the remaining portion of the wing had been crushed almost directly aft. A two-foot section of the leading edge of the left wing was found near the base of the 75 foot tree. That section, which was from an area directly in front of the fuel filler cap, was crushed aft in the shape of a circle with a diameter of approximately 18 to 24 inches. The crushed area was consistent with the leading edge impacting a standing tree, and the vertical axis of the center of the crushed area was essentially perpendicular to the lateral axis of the aircraft. The left wing main spar, which had been damaged both by the impact and the fire, had also been bent in the shape of an arc, with the mid-span portion pressed aft, and the area near the tip arcing forward. Due to the extent of the damage, complete control continuity could not be established, but all control cable were located and inspected, and no sections were found that indicated fraying or failure due to cable wear. The engine showed very little frontal impact damage, but it suffered severe fire damage, and all of the rear-mounted accessories had been destroyed. The number three cylinder head (aluminum) had partially melted away from the steel cylinder barrel, and a portion of the number three piston skirt had been melted by the fire. In addition, a six by six-inch by six-inch area of the crankcase near the base of the number three cylinder had been melted by the intensity of the fire. Due to the extent of the thermal damage, valve train continuity could not be established, but an inspection of the rockers, rocker bosses, camshaft, and accessory drive gears revealed no evidence of any anomaly or malfunction. A visual inspection of the crankshaft, crankshaft bearings, and the camshaft lobes was performed by looking through the hole melted in the crankcase and by removing two of the cylinders. That inspection did not reveal any evidence of a pre-accident lack of lubrication, nor any indication of mechanically produced thermal damage. There were no metal filings or contaminants found anywhere within the engine. There was no indication of lead fouling, contaminants, or unusual wear associated with the spark plugs. The propeller hub was still attached to the crankshaft flange, and both propeller blades were still attached to the hub. One blade was bent aft in a continuous arc, beginning at the blade root and ending at the tip, which was approximately 60 degrees aft of its normal plane. The other blade, which showed longitudinal twisting along its span, had been bent aft about 10 degrees, but was relatively straight from just outboard of the root to its tip. Both blades displayed considerable chord-wise scaring of their forward surface, and the leading edge of both blades contained numerous deep leading edge gouges. PERSONNEL INFORMATION The pilot was a 27 year old male, who earned his commercial pilot certificate on 12/13/02. At the time of the accident, he was a pilot for the United States Navy, and he was home on leave after recently returning from duty in the Middle-East. He had been promoted to aircraft commander in the E-2 (twin-engine turbo-prop) on June 7, 2005. He reportedly had accumulated about 850 hours of military fight time and about 150 hours of civilian flight time. Family members estimated that he accumulated around 40 hours total time in a Cessna 177. METEOROLOGICAL INFORMATION The 1750 surface aviation weather observation (METAR) for McCall, Idaho, which is located approximately 20 miles north of the accident site, reported winds of 270 degrees at 10 knots, more than 10 miles visibility, clear skies, a temperature of 24 degrees Celsius, a dew point of minus three degrees Celsius, and an altimeter of 29.99 inches of mercury. According to local authorities, the fire crew that responded to the scene reported strong, gusty, variable winds, mostly out of the north, and they estimated the ambient temperature to be about 75 degrees Fahrenheit. Based on the altimeter setting at McCall, and the estimated temperature at the scene, the density altitude was calculated to be over 10,000 feet (10,143). It was also noted by the fire crew that to a great extent the fire had burned down the slope, suggesting to them that the accident was on the leeward side of the ridge. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed by the Valley County Coroner's Office, and it was determined that the manner of death was accidental, with the cause being "complications of an aircraft accident." The FAA Forensic Toxicology Research Laboratory performed a forensic toxicology examination on specimens from the pilot, and the results were negative for ethanol and listed drugs. The standard tests for carbon monoxide and cyanide were unable to be performed. ADDITIONAL DATA AND INFORMATION The wreckage was released to Discount Aircraft Salvage, a representative of the owner, on November 9, 2005. At the time of the release the aircraft was located at the facilities of Discount Aircraft Salvage, in Deer Park, Washington.

Probable Cause and Findings

The pilot's failure to maintain clearance from a stand of conifer trees during low altitude maneuvering in mountainous terrain. Factors include the mountainous/hilly terrain, gusty winds, a high density altitude, and maneuvering at a low altitude.

 

Source: NTSB Aviation Accident Database

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