History of Flight
On September 5, 2013, about 1954 Alaska daylight time, a Cessna 170B airplane, N170BN, sustained substantial damage following a loss of control and impact with tundra-covered terrain approximately 74 miles northwest of Glennallen, Alaska. The airplane was operated by the private pilot as a visual flight rules (VFR) personal flight under 14 CFR Part 91. The sole occupant, the pilot, was fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed. The flight departed from a remote mountain ridge near the accident site.
According to a member of the pilot's hunting party, the pilot had shot and killed a moose earlier in the day but failed to mark its location before hiking away. Unable to locate the moose, he returned to the airplane and departed to conduct an aerial search.
A witness observed the airplane perform a series of low-altitude maneuvers. The airplane flew by at approximately 80 to 100 feet above ground, traveling at an estimated 45 mph. After passing, it began a left turn, then the nose pitched down abruptly and the airplane entered a spin, descending vertically nose-first into the tundra and brush.
Personnel and Aircraft Information
The 41-year-old pilot held a private pilot certificate with an airplane single-engine land rating. His most recent third-class medical certificate, issued June 10, 2011, required corrective lenses. According to FAA records, the pilot had about 186 total flight hours, with 12 hours in the previous 6 months.
The airplane was a 1952 Cessna 170B with a total time of 3,307.3 flight hours. Its most recent annual inspection was on July 12, 2013, 6.1 hours before the accident. The Continental Motors C145 engine (145 horsepower) had been overhauled 395.3 hours prior.
Meteorological Information
The nearest weather reporting facility, Eureka Lodge (about 38 miles southeast), reported at 1956: wind 230 degrees at 8 knots, visibility 10 statute miles, clear skies, temperature 46°F, dew point 35°F, altimeter 29.96 inHg.
Wreckage and Impact Information
Continuous poor weather delayed the NTSB on-site examination until September 8. The airplane impacted in a near-vertical attitude at approximately 3,750 feet mean sea level, on a heading of 060 degrees magnetic. All major components were at the main wreckage site.
The cockpit was extensively damaged, with the engine, firewall, and instrument panel displaced upward and aft. The mixture control was full forward, throttle near idle, carburetor heat off, and ignition switch in the "both" position. Both wings exhibited leading-edge crushing; the right wing had spanwise crushing, the left from root to mid-span. Both flaps were at about 20 degrees. The empennage was undamaged. Flight control continuity was verified.
Cut brush at the initial impact site showed flat angular fractures with black paint transfer marks. The engine sustained impact damage. One propeller blade exhibited torsional "S" twisting and chordwise scratching; the other had leading-edge gouging. Examination found no evidence of mechanical malfunctions or failures that would have precluded normal operation.
Medical and Pathological Information
A postmortem examination attributed the cause of death to multiple blunt force injuries. Toxicological testing was negative for carbon monoxide, alcohol, and drugs.