WPR15FA241

The pilot’s failure to maintain terrain clearance while maneuvering. Contributing to the accident was the pilots’ selection, for undetermined reasons, of a route different than the most commonly used route.

The owner/pilot and another pilot were on a visual flight rules personal cross-country flight near mountainous terrain. The wreckage was discovered after the sheriff's department responded to a call of a forest fire in the area. There were no reported witnesses to the accident sequence. Examination of the accident site indicated that the airplane impacted a hillside at an elevation of 3,093 ft above mean sea level, which was 2,029 ft above the departure airport's elevation. The 45-degree angle cut damage signature on a tree and the propeller damage signatures indicated that the engine was developing power at the time of impact. The fuselage, wings, and most of the empennage were consumed by a postimpact fire. No evidence of any preimpact mechanical anomalies was discovered with the engine or airframe. It could not be determined which pilot occupied which seat and who was manipulating the flight controls when the accident occurred. It is unknown why the pilots attempted to fly over the mountain range to the east rather than to use the most common flight route down the valley toward the south. Further, the location where they attempted to cross the rising terrain was very close to the airport, and a witness had seen the airplane depart and fly eastbound at an altitude of about 400 ft above ground level. Therefore, the pilots had a reduced amount of time and distance to climb the airplane to an altitude sufficient to clear the mountain range. The pilot's decision to turn eastbound to cross the mountain range placed the airplane in a situation that prevented a successful crossing, and the pilot failed to recognize that the airplane was unable to climb above the terrain until it was too late to escape.

An autopsy was performed on the pilot and the passenger August 25, 2015, by the Okanogan County Coroner's Office, Okanogan, Washington. The cause of death for the pilot and the passenger was determined to be "blunt force trauma and thermal injuries due to aircraft collision with ground". The FAA Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma performed toxicology on specimens from the pilot and the passenger. The test on the pilot's specimen did not detect a presence of volatiles in blood; however, it detected the following drugs: diphenhydramine and propranolol. The tests for cyanide and carbon monoxide were not performed. The test on the passenger's specimen detected a presence of ethanol in muscle; however it did not detect a presence of drugs in muscle. The tests for cyanide and carbon monoxide were not performed. An NTSB staff meteorologist prepared a factual report for the area and timeframe surrounding the accident. The National Weather Service (NWS) Surface Analysis Chart for 0800 depicted a low pressure center in southern Washington, with a north/south-oriented trough stretching from British Columbia to the south. Station models generally depicted calm and light and variable winds throughout the region. A weather observing station at Osoyoos (CWYY), British Columbia, Canada, reported at 0900 wind calm, temperature of 23 degrees C, and dew point temperature of 14 degrees C. Remarks: site does not have a precipitation sensor, sea level pressure of 1,014.1 milibars (Mb), temperature of 23.1 degrees C, and dew point temperature of 13.5 degrees, 3-hour pressure tendency: increasing, then decreasing 0.2 Mb. A North American Mesoscale (NAM) model sounding identified relatively light and variable winds below about 6,000 feet. Above this level, the wind became southwesterly with magnitudes between 15 and 20 knots through 10,000 feet. The entire atmosphere was dry, with relative humidity at or below 41 percent. The RAwindsonde Observation Program did not identify any significant levels of turbulence. The freezing level was identified as being at 14,300 feet. There were no publicly disseminated pilot reports made within 2 hours of the accident time in the vicinity of the accident site. The Geostationary Operational Environmental Satellite (GOES-15) visible imagery revealed mostly clear of cloud conditions above the surface. There were no Airmen's Meteorological Information (AIRMET) advisories active for the accident location at the accident time. There were no convective or non-convective Significant Meteorological Information (SIGMET) advisories active for the accident location at the accident time. It could not be determined which pilot occupied which seat, and which pilot was manipulating the flight controls when the accident occurred. The pilot/owner, age 88, held a private pilot certificate with airplane single-engine land, and instrument airplane ratings. A third-class airman medical certificate was issued on February 17, 2015 with the following limitation: must use hearing amplification. On his most recent medical certificate application, the pilot reported that he had accumulated 1,701 total flight hours. The pilot's personal logbook was not obtained during the investigation. The pilot-rated passenger was a Canadian citizen and flight information was not provided. The accident site was located on the side of a hill at an elevation of 3,093 ft msl. The airplane wreckage was spread along a 68 ft-long up-sloping path through a forest of Pinus Ponderosa on a 168-degree magnetic heading. The first identified point of impact was a Ponderosa pine tree that was broken off about 70 ft above the ground. The tree damage exhibited a 45-degree angle cut. The airplane's right wing tip, a section of the right wing, the right aileron, and the right flap were found about 43 ft southeast of the first impact point resting on the ground. All of the components exhibited signatures consistent with impact damage, and were charred, melted, and consumed by the fire. The terrain from the first point of impact to where the airplane's main wreckage came to rest was up-sloping at an angle of 4 degrees. The main wreckage, which consisted of the airplane's engine, propeller, cabin, left wing, both main landing gear, baggage compartment, aft fuselage, and empennage rested inverted with the nose of the airplane oriented to the south-east on a magnetic heading of about 128 degrees. These components were charred, melted, and consumed by fire. The four-seat, single-engine, high-wing, fixed landing gear airplane, serial number T18208870, was manufactured in 2008. It was powered by a Lycoming TIO-540-AK1A engine, serial number L-13038-61A, rated at 235 horse power. The airplane was also equipped with a McCauley three bladed constant speed propeller; the model and the serial number could not be determined. A review of maintenance records showed that the most recent annual inspection was completed July 14, 2015, at a total airplane time and a tachometer time of 295.5 hours. On August 13, 2015, about 0930 Pacific daylight time, a Cessna T182T, N6289Z, was destroyed when it impacted terrain while maneuvering near Oroville, Washington. The pilot, who was the registered owner of the airplane, and a pilot-rated passenger sustained fatal injuries. The flight was operated under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a personal cross-country flight. Visual meteorological conditions (VMC) prevailed at the time of the accident, and no flight plan had been filed. The flight originated from Dorothy Scott Airport (0S7), Oroville, about 0920, with an intended destination of Spokane International Airport (GEG), Spokane, Washington. About 0945, the Okanogan County Sheriff's department received a notification of a forest fire near Oroville. Upon arrival to the scene, Sheriff's department personnel discovered an airplane that was destroyed. The airplane was not positively identified at that time. On August 14, 2015, at 0031, an Alert Notification (ALNOT) was issued for an airplane after family members of the pilot became concerned when he did not arrive at his intended destination. Later that day, the airplane wreckage found by the sheriff's department was identified as the missing airplane. There were no reported witnesses to the accident sequence. According to the Federal Aviation Administration (FAA) Airport/Facility Directory information, 0S7 was equipped with a single paved runway, designated 15/33, and airport elevation was 1,064 feet above mean sea level (msl). The airport was not equipped with an air traffic control tower. A dedicated Common Traffic Advisory Frequency was specified for radio communications used by arriving and departing aircraft. The surrounding terrain was mountainous; to the east of the airport was the Okanogan Highlands, and on the west side was the Cascade Mountains. The airframe was examined at the accident site on August 15, 2015, by a representative from Textron Aviation and the NTSB IIC. Most of the airplane was consumed by the post-crash fire. The right wing flap exhibited signatures consistent with thermal damage. The flap actuator extension was measured at 3/16 inches, and investigators determined that the flaps were in a full up position. The wing flap control cables remained attached at both wing bellcranks, and separated at the wing root. The cable separations exhibited signatures consistent with a tension overload. Both right wing aileron cables remained attached to the right wing bellcrank, and were found separated at mid wing. The push-pull rod remained attached to the aileron. The left wing was located at the main wreckage, and was mostly consumed by the postimpact fire. The left wing aileron cables remained attached to the left wing bellcrank. Aileron flight control cable continuity was confirmed from the cockpit to each flight control surface via ailer