History of Flight
On August 31, 2012, at approximately 0920 mountain daylight time, a Piper PA-12, registration N3031M, was substantially damaged after striking mountainous terrain near Rye, Colorado. The private pilot and passenger were fatally injured. The flight was conducted under 14 CFR Part 91 with no flight plan filed, and visual meteorological conditions prevailed. The aircraft departed Pueblo Memorial Airport (PUB) at about 0806.
Witnesses, including law enforcement personnel, reported that the pilot and passenger arrived overhead their planned surveillance location and established radio contact with ground personnel. Multiple passes were observed at an altitude of 500 to 1,000 feet above ground level. The airplane then maneuvered westward and disappeared from sight. It subsequently impacted terrain about two miles west of the surveillance area in heavily wooded terrain at an elevation of 10,171 feet. A post-impact fire ensued.
Personnel Information
The pilot, aged 64, held a private pilot certificate with an airplane single-engine land rating. A Class 3 medical certificate was issued on March 12, 2012, with a corrective lenses requirement, valid until March 31, 2013. At the time of the medical examination, the pilot reported 900 total flight hours, with 50 hours in the preceding six months. Records indicated approximately 140 hours in the accident airplane. The pilot's girlfriend stated that he was very familiar with mountain flying and frequently flew in the mountainous areas of Colorado, including near Lake Isabel.
Aircraft Information
The accident airplane was a 1947 Piper PA-12, registered to Three Bushwhackers Incorporated LLC. An airworthiness certificate was issued on February 23, 1956. The aircraft was equipped with a Lycoming O-290-D2 135-horsepower engine, which had accumulated about 690 hours since its last field overhaul.
Meteorological Information
A Bureau of Land Management and United States Forest Service station (WLCC2), located about 3 miles northeast of the accident site at 9,053 feet elevation, recorded at 0856 a temperature of 64.0°F, dew point of 26.5°F, and wind from the east-southeast at 3 knots gusting to 5 knots. At 0956, temperature was 67.0°F, dew point 25.8°F, and wind from the east-southeast at 5 knots gusting to 10 knots.
A Citizen's Weather Observing Program station (D0665) about 15 miles west-northwest at 8,514 feet reported an altimeter setting of 29.86 inches of mercury at 0918. Using this altimeter setting and interpolated temperature (65.5°F) and dew point (26.2°F), density altitude was calculated at 11,600 feet for 9,000 feet elevation and approximately 13,000 feet for the accident site elevation of 10,171 feet.
Wreckage and Impact Information
The aircraft impacted remote, wooded, mountainous terrain and was consumed by fire. The terrain had a significant slope, and the impact heading was downslope. Trees uphill from the impact crater exhibited freshly broken and cut limbs.
Engine examination revealed that the crankshaft rotated by hand with compression on all cylinders. Engine drive train continuity was established. Cylinders were borescope-inspected with no anomalies noted. Spark plugs appeared worn out-normal per the Champion Check-a-Plug Chart. The oil pressure screen was debris-free. Both magnetos were heat-deformed and could not be rotated. The carburetor was mostly consumed; only the throttle plate remained. The propeller was attached to the crankshaft; both blades were bent aft with chord-wise scratches and leading-edge damage. Flight control system continuity was normal. Examination of the airframe, engine, and propeller revealed no pre-impact failure or malfunction.
Medical and Pathological Information
An autopsy on September 3, 2012, by the El Paso County Coroner attributed the cause of death to blunt force injuries. Toxicology tests by the FAA's Civil Aeromedical Institute detected no ethanol or drugs.
Tests and Research
The NTSB Office of Research and Engineering conducted a climb capability study using data from a pilot operating handbook for a similar aircraft with a 100-horsepower engine, adjusted for the accident aircraft's 135-horsepower engine. At an estimated weight of 1,600 pounds (425 pounds for pilot and passenger plus estimated fuel weight) and density altitude of 13,000 feet, climb rate capability was about 350 feet per minute, and climb gradient about 240 feet per mile.
Terrain west of the surveillance area was evaluated. A valley following the Saint Charles River bends southwest after about a mile, with rising elevation toward a ridge where the accident site was located. The ridge climbs to over 11,400 feet within one mile of the site, with terrain gradient exceeding 1,000 feet per mile.