20121014023879A

On October 14, 2012 at approximately 1910 MST, aircraft N151SV impacted the ground in a remote area in pima county, Arizona. The pilot, who was the sole occupant onboard, suffered fatal injuries. The aircraft last departed benson, AZ (E95) at approximately 1830 MST on a personal flight under the provisions of 14 CFR part 91 and was en route to imperial valley, CA (ipl). Earlier in the day the pilot flew from ipl with one passenger, his wife, to E95 then continued to las cruces, NM (lru). N151SV departed lru with only the pilot and landed in E95 for fuel, then departed E95 destined for ipl.N151SV was receiving VFR flight following by abq ARTCC per request by the pilot. Radar tracking from albuquerque ARTCC begins 7 miles west of E95 at 1837 MST at an altitude of 6600' asl. The aircraft continues in a nwn direction reaching an altitude of 8500' asl. At 1801 and 50 seconds the aircraft appears to make a series of slight turns to the left and right then continuing back on course at 1802 and 13 seconds. Between 1902 and 54 seconds and 1905 and 3 seconds, while still maintaining 8500', the aircraft again begins a series of increasing left and right turns. The radar tracks then show the aircraft head in a wsw direction and soon begin to lose altitude. The aircraft then makes a 360? Right turn with radar tracking terminating at 1907 and 22 seconds at an altitude of 6600' asl. The final radar hit was approximately .6 of a mile from the accident site. Numerous attempts by abq center to contact N151SV were unsuccessful. An alnot was issued and a blackhawk helicopter operated by the border patrol located the wreckage. The aircraft wreckage was discovered in an unpopulated desert area consisting of shrubs, saguaro, prickly pear, and cholla cactus and palo verde trees, 15 miles wsw of the Marana regional airport (avr) with GPS coordinates of 32?19'31"n and 111?27'10"w at an elevation of 2365' asl. Ground scars indicate the aircraft impacted level ground at a heading of 300?. The aircraft's right wing tip first impacted the ground as evidenced by fragments of green colored glass, identified as from the right navigation light lens, along the initial ground scar. An observed contact point on a tree branch at an elevation of 12' and 29' prior to the initial ground impact point suggests the aircraft's flight path was descending at an angle of 67?.the METAR weather report from ryan field, AZ (ryn) at 0153Z (1853 MST) had the winds 330? At 5 knots. The skies were clear with 25 mile visibility. Barometric pressure was 33.00 "hg and the temperature was 77?f. the sunset was at 1752 MST and civil twilight was at 1817 MST. The moon had a waning crescent with only 1% illuminated and had set at 1715 MST.all examined airframe, engine, and accessories lacked any evidence that would indicate mechanical failure. Physical evidence of the damage to the propeller is consistent with impact with the ground while the engine is producing power. There was no conclusive evidence to show the aircraft was not operating in a normal condition. Based on radar tracks in the final minutes before the accident it is apparent the pilot experienced some sort of incapacitation. The reason for this incapacitation could have been due to a sudden medical condition, spatial disorientation, or loss of consciousness.