History of Flight
On October 4, 2009, about 0725 mountain standard time, a Piper PA-24-250 airplane, N7471P, was substantially damaged when it collided with terrain near Black Canyon City, Arizona. The airplane was registered to Chief LLC of Aguila, Arizona, and operated by the pilot under Title 14 Code of Federal Regulations Part 91. The airline transport pilot and his sole passenger were killed. General visual meteorological conditions prevailed, and no flight plan was filed for the personal cross-country flight, which originated from St. John's Industrial Airport, St. Johns, Arizona, at 0600, with an intended destination of Aguila, Arizona.
A family member reported the airplane overdue to the FAA on the morning of October 5, 2009, leading to an Alert Notification. Later that afternoon, United States Forest Service firefighters reported locating the wreckage while fighting a wildfire near the 5,499-foot level of the Bradshaw Mountain Range. The fire in the area was initially reported about 1600 on October 4, 2009.
Radar data showed the flight at 8,500 feet pressure altitude about 50 miles east of the accident site, on a west-southwest heading. A descent from 6,900 feet at 0723 to 5,700 feet at 0725 was recorded, with slight left and right turns. The last radar target was 0.32 miles southeast of the site at 5,700 feet.
Radio communications revealed that at 0700, the pilot told Albuquerque ARTCC he would "drift down a little bit lower to stay under the clouds." At 0716, he was given a frequency change and contacted the new sector at 0717, acknowledging an altimeter setting of 29.67. No further transmissions or distress calls were received.
Personnel Information
The pilot, age 74, held an airline transport pilot certificate with multiengine land ratings, and a commercial pilot certificate with single-engine land and sea ratings. A third-class medical was issued on October 10, 2008, with the limitation "must have available glasses for near vision." His logbook was not recovered. On his most recent medical application, he reported 22,239 total flight hours.
Aircraft Information
The four-seat, low-wing, retractable-gear airplane, serial number 24-2662, was manufactured in 1961. It was powered by a Lycoming O-540-A1D5 engine and equipped with a Hartzell HC-A2MVK-1 variable-pitch propeller. An annual inspection was completed on October 1, 2009, at a tachometer reading of 2,649.03 hours, with engine time since major overhaul of 527.16 hours. The tachometer was damaged at the accident site.
Meteorological Information
An NTSB meteorologist prepared a factual report. The NWS Surface Analysis Chart depicted a trough of low pressure over western Arizona with southerly winds of 10 to 20 knots. The Radar Summary Chart at 0740 showed light rain showers over central Arizona with echo tops from 18,000 to 20,000 feet. Composite radar at 0725 showed reflectivity values of 10 to 35 dBZ near the accident site.
The nearest weather station, Humbug Creek RAWS (elevation 5,250 feet, 3 miles west), recorded at 0648: wind from 216 degrees at 22 knots gusting to 31 knots, temperature 56°F, dew point 56°F, relative humidity 100%. At 0748: wind from 209 degrees at 23 knots gusting to 35 knots, temperature 54°F, dew point 54°F, humidity 100%.
Sunset Point RAWS (8 miles northeast, elevation 2,960 feet) recorded at 0653: wind from 039 degrees at 12 knots gusting to 17 knots, temperature 62°F, dew point 56°F, humidity 81%. At 0753: wind from 022 degrees at 10 knots gusting to 21 knots, temperature 62°F, dew point 57°F, humidity 84%.
Phoenix Deer Valley Airport (28 miles south-southeast) reported southeasterly winds, unrestricted visibility, and variable clouds between 3,700 and 4,200 feet AGL. Prescott's Ernest A. Love Field (32 miles north-northwest) reported at 0708: wind from 170 degrees at 12 knots gusting to 21 knots, visibility 10 miles, broken clouds at 2,700, 3,700, and 5,500 feet AGL. Luke Air Force Base (37 miles south-southwest) reported at 0725: wind from 120 degrees at 7 knots, visibility 10 miles, broken clouds at 3,900 feet AGL.
Upper air soundings from Flagstaff (70 miles north-northeast) indicated a moist low-level environment with lifted condensation level at 1,813 feet AGL, relative humidity 75% or more from the surface to 13,500 feet, and saturated conditions from the LCL to 13,000 feet. The atmosphere was moist and conditionally unstable below inversions, supporting nimbostratus to stratocumulus clouds. The freezing level was at 11,161 feet, with shallow icing conditions to 13,000 feet. The sounding wind profile showed surface wind from 170 degrees at 9 knots veering to the southwest with height, and a low-level jet from 210 degrees at 48 knots at 9,931 feet. Mean 0-6 km wind was from 230 degrees at 43 knots.
A NAM12 model sounding for 0800 depicted saturated conditions from the LCL at 542 feet AGL (6,021 feet MSL) to approximately 9,000 feet, implying mountain obscuration. The wind profile showed southerly wind veering to the southwest. At 5,518 feet, wind was estimated from 200 degrees at 30 knots. Model data indicated a 100% probability of light to moderate turbulence at 5,480 feet due to vertical wind shear of 14.1 knots per 1,000 feet.
GOES-12 satellite visible imagery at 0702 and 0732 showed the accident site under a broken to overcast layer of low stratocumulus clouds. Infrared imagery indicated cloud top temperatures of 276-278 K, corresponding to cloud tops near 10,000 feet.
Flagstaff WSR-88D radar (58 miles northeast) at 0715:55, 0725:39, and 0735:21 depicted light to moderate echoes over central Arizona. At 0725, echoes of 20 dBZ extended west and north of the accident site, with no echoes directly over the site.
Pilot reports indicated icing in clouds between the freezing level and 14,000 feet (trace to moderate), moderate turbulence between 8,000 and 15,000 feet, and one report of moderate to occasional severe turbulence below 5,000 feet over the Grand Canyon. There were urgent reports of low-level wind shear in the Prescott area and updrafts/downdrafts of ±400 fpm.
The Area Forecast for northern Arizona, valid from 0630 to 1600 on October 4, indicated scattered to broken clouds at 9,000-10,000 feet with tops to 15,000 feet, southwest wind 25 knots gusting to 35 knots. After 1100, widely scattered light rain showers with southwest wind 30 knots gusting to 50 knots.
The pilot contacted AFSS prior to departure at 0600, requesting a standard weather briefing for a VFR flight at 10,500 feet from St. Johns to "E35" (Fabens, Texas), though his intended destination was Aguila (E25). The briefer noted recommended eastbound cruising altitudes (odd thousands plus 500 feet) and advised of AIRMETs for mountain obscuration, IFR conditions, and occasional moderate turbulence below 18,000 feet, stating VFR flight was not recommended. The pilot then asked for current conditions at St. Johns, Phoenix, and Prescott, which were VFR with strong southwesterly winds. The pilot did not correct the destination or cruising altitude.
Wreckage and Impact Information
Wreckage debris was located on the eastern side of a mountain range at an elevation of 5,488 feet MSL. The energy path was oriented on a 260-degree heading, with debris within about 200 feet of the main wreckage. The first identified point of contact (FIPC) was a large flat top rock with blue paint transfer and scratches. Damaged trees were found four feet beyond the FIPC, and impact impressions on a vertical rock face 10 feet beyond. The right wing was observed upright between the rock face and FIPC. Propeller remains were found 20 feet up on the rock face.
The main wreckage was 80 feet left of the FIPC. The empennage was inverted, and the left wing was inverted adjacent to the main wreckage. Both wings were separated from the fuselage. The center fuselage was consumed by post-impact fire. Cockpit controls and instruments were displaced. The left and right wings had compression damage along leading edges; ailerons and flaps remained attached. Flight control continuity was established to the wing roots, with cable separations consistent with tension overload. The empennage exhibited fire damage; the horizontal stabilator, vertical stabilizer, and rudder were intact. Control continuity to the cockpit was established, with cable separations consistent with overload. The pitch trim drum was measured in neutral position.
The engine exhibited cylinder and accessory displacement. The propeller was separated from the crankshaft flange. One blade was separated from the hub; the other remained partially attached. Both blades showed thermal discoloration, gouging, and twisting opposite rotation. The exhaust muffler was displaced and showed no oil residue.
Medical and Pathological Information
An autopsy conducted on October 8, 2009, determined the pilot's cause of death as "blunt impact injuries." Decomposition was noted. Toxicological testing by CAMI detected ethanol in multiple tissues: 29 mg/dL in lung, 27 in liver, 27 in kidney, 22 in spleen, 18 in brain, and N-propanol in lung and brain. Due to the two-day delay in body recovery, it could not be determined if the alcohol was ingested or resulted from postmortem decomposition.
Fire
A post-impact fire sparked a localized wildfire limited to about three acres. The fire burn area extended from the FIPC down slope, consuming trees and vegetation.
Tests and Research
The recovered engine and airframe were examined on November 10, 2009. The fuel selector valve was intact and positioned on "LEFT AUX" with no obstructions. Two air-driven gyros were recovered; one from the attitude indicator showed no scoring, the other was intact and undamaged. No evidence of preimpact mechanical malfunction was observed on the airframe.
Engine examination revealed severe fire and impact damage. The number one cylinder was separated; the crankcase and accessory housing were destroyed by fire, exposing internal components. All internal components appeared intact and undamaged. No evidence of heat distress, detonation, or foreign object ingestion was observed. The left magneto was destroyed by fire; the right magneto was also destroyed. The propeller governor was separated and impact-damaged. The carburetor was fractured; the fuel screen was free of debris. The starter, alternator, oil filter, and vacuum pump were damaged or destroyed. No evidence of preimpact mechanical malfunction was observed.