History of Flight
On June 3, 2009, at approximately 1421 mountain daylight time, a Cessna 182M, registration N70946, collided with mountainous terrain about 10 miles north of Atlanta, Idaho. The private pilot was operating under Part 91. The pilot was killed, and the airplane sustained substantial damage. Visual meteorological conditions prevailed, and no flight plan had been filed. The personal flight originated from Boise, Idaho, around 1400.
Radar data showed a track beginning at 1401, 10 miles northeast of Boise Airport at 7,400 feet mean sea level (msl). The track continued northeast at 8,200 feet msl, then increased to 8,700 feet msl during the last two minutes. The final radar return at 1421 was at 8,600 feet msl, near the wreckage location. The highest terrain in the area is 9,580 feet msl.
Two portable GPS units (Garmin 196 and 396) were recovered. The Garmin 196 had no data for the accident flight. The Garmin 396 had corrupted time data but valid position, altitude, ground speed, and heading data. Its track started at Boise Airport and proceeded northeast at 8,350 feet msl, rising to 8,891 feet msl about two minutes from the end, then stopping at the wreckage site.
Pilot Information
The 36-year-old pilot held a private pilot certificate with an instrument rating, issued August 31, 2004. He had a third-class medical certificate with a near-vision correction limitation, issued March 13, 2008. His logbook showed 809.0 total flight hours, with 41.8 hours in the previous 90 days. His last flight review was completed June 7, 2007.
The airplane owner stated the pilot had taken back-country flying courses and was an experienced mountain flyer. According to a Boise police report, the pilot and his spouse were having marital issues and had argued earlier that day. The pilot's car at the airport contained two self-help books about spousal infidelity. The owner said he was aware of the pilot's marital problems and was concerned about his state of mind.
Aircraft Information
The four-seat, high-wing, fixed-gear Cessna 182M, serial number 18259429, was manufactured in 1969. It was powered by a Teledyne Continental Motors O-470-R 230-hp engine with a McCauley 2A34C203-C constant-speed propeller. Maintenance records showed an annual inspection completed on May 22, 2009, at a tachometer reading of 5,051.2 hours. Total airframe time was 5,051.2 hours, and engine time since major overhaul was 191.2 hours. The Hobbs meter and tachometer were not found.
Meteorological Information
At Boise Airport (elevation 2,872 feet msl, 60 miles southwest of the accident), the 1453 ASOS reported few clouds at 6,500 feet agl, 10 miles visibility, wind from 150° at 9 knots, and altimeter 29.98 inHg.
At Friedman Memorial Airport, Hailey (elevation 5,318 feet msl, 50 miles southeast), the 1447 AWOS reported few clouds at 4,500 feet agl, scattered at 8,000 feet agl, 20 miles visibility, wind from 140° at 8 knots, and altimeter 30.12 inHg.
At Challis Airport (elevation 5,072 feet msl, 53 miles northeast), the 1455 ASOS reported scattered clouds at 7,500 and 9,000 feet agl, 10 miles visibility, wind from 320° at 4 knots, and altimeter 30.07 inHg.
Weather radar (KCBX, 54 nm southwest) indicated lowest reflectivity (<10 dBZ) near the accident site at about 2,800 meters msl, suggesting cloud bases near 8,500 feet msl. GOES-11 satellite imagery showed multi-layered clouds over Idaho, with brightness temperature at the accident site of -11°C, corresponding to cloud tops above 15,000 feet msl. Sky condition was consistent with few to scattered coverage (2/8 to 4/8), and visibility in clear areas was estimated at >3 miles.
Wreckage and Impact
The wreckage was at the base of a vertical rock cliff in the Sawtooth National Forest, about 500 feet below a ridge line. The rock face above had black discoloration consistent with soot. Ridge elevation above the wreckage ranged from 9,100 to 9,580 feet msl. Due to remote location and weather, recovery occurred on July 7, 2009.
Examination on July 21 at Boise Airport revealed extreme fragmentation; most pieces were smaller than 3–4 feet. The wing spar was in two sections. Both lift struts and cabin doors were present. Landing gear components were all present. The engine mount, cockpit controls, and tail were tangled together. The engine was separated from its mount. Control continuity was established through multiple cable overload separations. Both propeller blades were fragmented with leading edge gouging and twisting. Flap jack screw extension was 0.45 inches (0° flaps). Elevator trim jack screw extension was 1 inch (10° nose-up trim). The fuel selector was on the left tank.
Medical and Pathological Information
An autopsy on June 7, 2009, by the Elmore County Coroner listed cause of death as blunt force trauma due to an aircraft accident. Forensic toxicology by the FAA found no carbon monoxide, cyanide, ethanol, or drugs in the pilot's blood.