N70946Cessna 182M · 1968

On June 3, 2009, about 1421 mountain daylight time, a Cessna 182M, N70946, collided with mountainous terrain approximately 10 miles north of Atlanta, Idaho. The private pilot operated the airplane under the provisions of Title 14 Code of Federal Regulations Part 91. The pilot was killed, and the airplane was substantially damaged. Visual meteorological conditions prevailed, and no flight plan had been filed. The personal flight originated from Boise, Idaho, around 1400.

A review of radar data identified a tracking starting at 1401, 10 miles northeast of the Boise airport at 7,400 feet mean sea level (msl).

The tracking continued on a steady northeasterly course at an elevation of 8,200 feet msl. During the last 2 minutes of the data the track increased in altitude to 8,700 feet msl. The final radar return occurred at 1421, at 8,600 feet msl, and was in the immediate vicinity of where the airplane wreckage was located. The highest terrain elevation in the vicinity of the wreckage is 9,580 feet msl.

Two portable global positioning system (GPS) units (Garmin 196 and a Garmin 396) were recovered from the wreckage and sent to the Safety Board Vehicle Recorder Laboratory for data recovery. The Garmin 196 contained no data for the accident flight. The Garmin 396 recovered GPS tracklog contained corrupted time data, but position, altitude, ground speed, and heading data files remained uncorrupted. The track starts at the Boise airport, and proceeds on a direct northeast course at 8,350 feet msl. About 2 minutes from the end, the track increases in altitude to 8,891 feet msl, and abruptly stops at the location where the wreckage was found.

The pilot, age 36, held a private pilot certificate for airplane single-engine land with an instrument airplane rating, issued on August 31, 2004. The pilot held a third-class medical certificate with the limitation that he possess glasses that correct for near vision, issued on March 13, 2008. Examination of copies of the pilot’s logbook revealed that he had 809.0 hours of total airplane time, and had accumulated 41.8 hours within the last 90 days. His latest flight review was recorded as completed on June 7, 2007.

According to the owner of the airplane, the pilot had taken back-country flying courses and was an experienced mountain flyer.

The Boise police report stated that the pilot and his spouse were having marital issues and that they had an argument earlier on the day of the accident. The police inspected the pilot’s automobile that was left at the airport and found two self-help books addressing spousal infidelity.

The owner of the airplane stated that he was aware of the pilot’s marital problems and was worried about his state of mind when he left the airport.

The four seat, high-wing, fixed gear airplane, serial number (S/N) 18259429, was manufactured in 1969. It was powered by a Teledyne Continental Motors O-470-R, 230-hp engine, equipped with a McCauley model 2A34C203-C constant speed propeller. Review of copies of maintenance logbook records showed an annual inspection was completed on May 22, 2009, at a recorded tachometer reading of 5,051.2 hours, airframe total time of 5,051.2, and engine time since major overhaul of 191.2 hours. The Hobbs meter and tachometer were not located or identified during the wreckage examination.

The Boise airport, elevation 2,872 feet msl, is located 60 miles southwest of the accident location. The Boise Automated Surface Observation System (ASOS) data for June 3, at 1453, recorded few clouds at 6,500 feet above ground level (agl); 10 miles visibility; wind from 150 degrees at 9 knots; and the altimeter setting was 29.98 inHg.

The Friedman Memorial Airport, Hailey, Idaho, elevation 5,318 feet msl, is located 50 miles southeast of the accident location. The Friedman Automated Weather Observation System (AWOS) data for June 3, at 1447, recorded few clouds at 4,500 feet agl, scattered clouds at 8,000 feet agl; 20 miles visibility; winds from 140 degrees at 8 knots; and the altimeter setting was 30.12 inHg.

The Challis Airport, Challis, Idaho, elevation 5,072 feet msl, is located 53 miles northeast of the accident location. The Challis automated surface observation system (ASOS) data for June 3, at 1455, recorded scattered clouds at 7,500 feet agl, scattered clouds at 9,000 feet agl; 10 miles visibility; winds from 320 degrees at 4 knots; and the altimeter setting was 30.07 inHg.

Base reflectivity weather radar imagery (RHI scan) from a station (KCBX) located approximately 54 nautical miles (nm) southwest of the accident site, indicated lowest reflectivity returns (less than 10 dBZ) in the vicinity of the accident site to be near 2,800 meters msl, suggesting cloud bases may have been 8,500 feet msl. GOES-11 satellite imagery around the time of the accident identified multi-layered clouds over Idaho, with brightness temperatures at the accident site, retrieved using GOES-11 channel four (10.7µm), to be about -11°C. This brightness temperature corresponds to cloud tops greater than 15,000 feet msl. Sky condition is consistent with 2/8 to 4/8 cloud coverage (few to scattered clouds), and visibility in cloud-free areas is estimated at greater than 3 miles.

The wreckage was located at the base of a vertical rock cliff face in the heart of the Sawtooth National Forest, approximately 500 feet below a mountain ridge line. The rock face was discolored black above the main wreckage in a manner consistent with soot. Topographical map software was used to determine the ridge line elevation directly above the wreckage varied from 9,100 feet to 9,580 feet msl. Due to the remote accident location and prevailing weather conditions, recovery personnel waited until July 7, 2009, to complete the wreckage recovery.

An examination of the wreckage was conducted under the supervision of the Safety Board investigator-in-charge (IIC) in a hangar at the SP Aircraft facility at the Boise airport, on July 21. The wreckage was sorted, laid out, and the engine was hung on an engine hoist for examination.

Overall the wreckage was extremely fragmented; most elements were in pieces smaller than 3 to 4 feet in size. The wing spar was in two sections, left wing and right wing, with the separation of the two in the cockpit cabin area. Both lift struts were present, as were both cabin doors.

All landing gear components were present.

Sections of the engine mount, cockpit controls, and tail were co-mingled together in a ball. The engine was not attached to the engine mount.

Control continuity was established between all control bell cranks and the cockpit bell crank connections, through multiple control cable overload separations.

Both blades of the propeller were fragmented and exhibited leading edge gouging and twisting along the longitudinal axis.

The flap jack screw extension was 0.45 inches, which corresponded to 0 degrees of flap. The elevator trim jack screw extension was 1 inch, which corresponded to 10 degrees tab down (nose up) trim. The fuel selector valve was positioned to the left fuel tank.

An autopsy was performed on the pilot on June 7, 2009, by the Elmore County Coroner, Mountain Home, Idaho. The autopsy findings listed the cause of death as, “Blunt force trauma due to an aircraft accident.”

Forensic toxicology was performed on specimens from the pilot by the Federal Aviation Administration (FAA) Forensic Toxicology Research Team, Oklahoma City, Oklahoma. The toxicology report stated no carbon monoxide, cyanide, ethanol, or drugs were detected in blood.