NTSB Factual Report

HISTORY OF FLIGHT

On October 14, 2012, at 1908 mountain standard time, a Piper PA-28-151, N151SV, collided with desert terrain near Marana, Arizona. The pilot/owner was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The private pilot, the sole occupant, sustained fatal injuries; the airplane was substantially damaged. The personal cross-country flight departed from Benson Municipal Airport, Benson, Arizona, about 1835, with a planned destination of Imperial County Airport, Imperial, California. Dark night visual meteorological conditions prevailed along the intended route of flight, and the pilot was receiving visual flight rules (VFR) flight following services; he had not filed a flight plan.

Earlier in the day, the pilot had flown with his spouse from his home base airport in Imperial. The first leg of the flight was to Benson, where the pilot would typically refuel the airplane, and then they continued to their destination of Las Cruces International Airport, Las Cruces, New Mexico. The pilot's spouse stayed in Las Cruces and he departed for Benson about an hour thereafter with the ultimate destination being Imperial.

Recorded radar data and Air Traffic Control (ATC) recordings were obtained and reviewed by a National Transportation Safety Board investigator. Recorded radar data covering the area of the accident was examined for the time frame, and a discreet secondary beacon code target was observed that matched the anticipated flight track of the airplane en route from Benson to Imperial. The radar data consisted of about 30 minutes of returns from 1838:02 to 1907:22. The returns were consistent with the airplane flying in a northwesterly direction, and the mode C altitude gradually climbing from about 6,600 feet mean sea level (msl) to peak altitude of 8,600 feet msl.

A review of the data disclosed that about 1850 the track was over Tucson International Airport, Tucson, Arizona, cruising at an altitude around 8,500 feet msl. The track continued another approximate 35 miles with a majority of the radar returns spaced uniformly and following a track of about 300 degrees true. At 1904, the track departed from the northwesterly flight path, consistent with the airplane making a left turn and flying west for a mile. The track then made a series of turns, and it appeared the airplane turned back to the northwest direction for about 2 miles. The course turned southwest for 2 miles, and began to descend. The returns then made a 360-degree turn from 1906:03 until the last hit at 1907:22, during which time the altitude decreased 1,700 feet to 6,600 msl. The last radar return was about 0.8 nm southwest of the accident location.

PERSONNEL INFORMATION

According to the Federal Aviation Administration (FAA) Airman and Medical record files, the 57 year old pilot held a private pilot certificate with an airplane rating for single-engine land, which was issued on April 22, 2012. The pilot's most recent third-class medical certificate was issued on September 08, 2010, containing the limitation that he must wear corrective lenses for near and distant vision. There were no records of a more recent medical examination for a new medical certificate.

The pilot's flight records were found in the wreckage, and consisted of a bound logbook dated from April 10, 2011, to September 19, 2012. The summation of flight hours from the logbook revealed that the pilot had accumulated 185 hours of total flight experience, primarily all of which were flown in the accident airplane. The logs additionally disclosed that he had accrued 7.3 hours of flight time in nighttime conditions.

Based on the airport identifiers listed in the logs for flight origin and destination points, the pilot had completed the same trip twice before. The first trip recorded was dated May 2012 where he logged 4.7 hours from Imperial to Las Cruces and the following day, logged 5.1 hours for the return trip. A stop in Benson was noted on both legs where the pilot presumably refueled the airplane (no nighttime flight hours were recorded on that flight). The second trip was recorded as occurring in September 2012 with the flight to Las Cruces recorded as taking 5.5 hours. The following day, the pilot recorded a 1.2 hour flight in the local area. A separate entry for that day recorded the flight from Las Cruces back to Imperial with a stop in Benson, 0.4 hours of which was in night conditions.

The pilot's family members stated that they looked at the pilot's daily work activity sheets, and provided copies of his telephone records. They stated that he had been busy with work the 3 days before the accident. He appeared to have worked into the early morning on October 13 and then went back to work at 0700, getting little sleep. He awoke about 0430 on the day of the accident, which was not unusual.

The pilot had intended to leave about 0600 that Sunday morning, but the actual departure was about 0800. The trip was further delayed by a headwind and having to refuel in Benson. The pilot ate in Las Cruces, and was in a hurry to depart to get back to Imperial. The accident flight was the first time that he attempted to make the trip to Las Cruces and back in the same day.

AIRCRAFT INFORMATION

The Piper PA-28-151, serial number 28-7515119, was manufactured in 1974, and purchased by the pilot in May 2011. The airplane's maintenance records revealed that the last annual inspection was performed on August 1, 2012. An estimated airframe total time of 4,657.2 hours at the time of the accident was determined by adding the pilot's total flight time since the last maintenance performed. The airplane was equipped with the originally installed four-cylinder Lycoming O-360-E3D engine, serial number L-39304-27A. According to the logbooks, last recorded maintenance on the engine was performed during the annual inspection, and it was noted that at that time, it had accumulated about 90 hours since the last major overhaul.

Fuel receipts located within the wreckage indicated that while in Benson, the pilot added about 28 gallons of fuel at 1216, and then added about 14 gallons at 1804.

METEOROLOGICAL INFORMATION

The closest aviation weather observation station was located at Tucson International Airport, about 35 miles southeast of the accident site, at an elevation of 2,650 feet mean sea level (msl). A routine aviation weather observation (METAR) was issued 15 minutes prior to the accident, at 1853, and reported the following conditions: wind from 360 degrees at 3 knots; visibility 10 statute miles; clear sky conditions; temperature 27 degrees Celsius; dew point -3 degree Celsius; and altimeter setting of 30.01 inches of mercury (inHg).

Data from the United States Naval Observatory indicated that the phase of the moon was waning crescent with 1-percent of the Moon's visible disk illuminated. The sunset occurred at 1750, and the end of civil twilight was 1815.

WRECKAGE AND IMPACT

The wreckage was approximately 0.8 miles north of the last radar return at an elevation of about 2,365 feet msl. The accident site was located in unpopulated desert terrain, with the debris stretching over 470 feet from the first impact point to the farthest debris found (right main landing wheel). The main wreckage was situated at the end of the debris field; the energy path was oriented on a heading of about 300 degrees. In character, the terrain was comprised of dirt and rocks, populated by scattered brush and cactus typical of the southern Arizona region.

The main wreckage was located next to a tree on a northeast facing slope of the slightly inclined terrain that made up one side of a drainage ditch. The main wreckage consisted of the inboard left wing (and flap), the fuselage undercarriage portion of the cockpit, the tail section (vertical stabilizer, rudder, inboard portions of the stabilator), and the aft portion of the empennage. All control surfaces were accounted for at the accident site.

The first identified point of contact consisted of cut branches about 12 feet high in a tree located at the beginning of the debris field. About 30 feet from the tree was disrupted dirt where a crater was located with blue lens fragments found embedded in the soil. The crater was consistent in size and orientation to that of the right wing tip. Given the height of the cut tree branches and the distance of the impact crater from that point, the calculated descent angle would be 67 degrees.

A larger impact area, just beyond the impact crater, contained loose dirt and airplane debris with displaced dirt covering the ground in the direction of the wreckage path. The engine came to rest in a ravine 410 feet from the initial impact point. The propeller was located partially buried in dirt about 50 feet from the initial impact point.

A detailed wreckage diagram is appended to this report in the public docket.

MEDICAL AND PATHOLOGICAL INFORMATION

The Pima County Sherriff's Office Pima County, Arizona, completed an autopsy on the pilot. The FAA Toxicology and Accident Research Laboratory performed toxicological testing on specimens of the pilot. The results of the analysis of the pilot's specimens revealed no evidence of ethanol or drugs.

TESTS AND RESEARCH

The wreckage was recovered and transported to the facilities of Air Transport, Phoenix, Arizona, for a detailed examination. Present to the examination was a Safety Board investigator, as well as a representative from both Piper Aircraft and Textron Lycoming.

Airframe

The left wing separated into two major portions with the inboard half attached to remnants of the lower center fuselage section. The left flap remained partially attached to the inboard wing section. The left aileron had separated from the outboard half of the wing. The aileron bellcrank was separated from the wing structure. Both the primary and balance cable ends remained attached to the bellcrank, which exhibited deformation on its respective arms.

The right wing experienced extensive fragmentation, and the entire right wing had separated from the fuselage at the wing root. The outboard wing tip section exhibited diagonal accordion type crushing from the leading edge running inboard. The aileron surface separated from the wing, and sustained impact damage. The flap surface was broken at about mid span, and separated from the wing. The aileron bellcrank remained attached to the wing structure. Both the aileron primary and balance cables ends remained attached to the bellcrank, which exhibited deformation on its respective arms.

The flap torque tube assembly separated from the center fuselage section. The ratcheting detents of the flap lever were bent and separated. Due to the damage sustained, the position of the flaps could not be determined.

The empennage section of the aircraft sustained extensive ground impact damage and had sustained major crush damage. The empennage section separated from the cabin area. The empennage enclosure skins were ripped and torn into several sections. The rudder remained attached to the vertical stabilizer, which was still attached to the aft section of the fuselage. The stabilator was still attached to the tail section. Both rudder cables remained attached to the rudder horn. Both stabilator cables remained attached to the balance weight tube assembly. The stabilator trim jack screw exhibited 7 exposed threads with 5 threads being neutral and 16 threads corresponding to a full nose up trim setting.

The fuel selector valve (located on the left side of the cabin in front of the pilot's seat) had separated from the airplane. The valve handle was broken and separated from the valve assembly. The valve was disassembled, and found to be in the 'off' position. The fuel gascolator assembly remained attached to the selector fuel line.

Engine

The engine mount support tubes separated between the engine and firewall separating the engine from the airframe. A majority of the crankcase was intact, but the aft portion consisting of accessory drive gears had mostly broken away.

As a result of the crush damage, crankshaft rotation could not be accomplished. To facilitate further internal examination, holes were drilled through the top of the engine case material in-line with the rotational plane of each connecting rod. A lighted borescope was inserted to visualize each connecting rod, crankshaft, and camlobes at the respective cylinder position. There was no evidence of lubrication depravation or contamination found. The crankshaft and attached connecting rods showed no evidence of heat distress. The camshaft was intact, and each of the camlobes did not appear misshapen. According to the Lycoming representative, the combustion chambers of the cylinders remained undamaged by any foreign object ingestion. The gas path and combustion signatures observed at the spark plugs, combustion chambers, and exhaust system components displayed coloration consistent with normal operation.

The spark plugs were removed, examined, and photographed. The spark plug electrodes remained mechanically undamaged, and according to the Champion Spark Plugs Check-A-Plug chart AV-27, the spark plug electrodes displayed coloration consistent with normal operation. Both magnetos, which were sheared from the engine, were examined. The left magneto impulse coupler drive was found intact and secure. The drive functioned normally during hand rotation of the drive. The magneto produced spark at the four leads during hand rotation of the drive. The right magneto was fragmented and sustained damage that rendered the unit inoperative and therefore, could not be functionally tested.

The accessory gears including the crankshaft gear, bolt, and dowel were intact and remained undamaged by any pre impact malfunction.

The propeller had separated from the engine crankshaft. The propeller blades displayed leading edge gouging, torsional twisting, chordwise striations across the cambered surface, and trailing edge "S" bending. The signatures were consistent with the absorption of rotational forces applied at the crankshaft at the time of impact.

There was no evidence of any preimpact mechanical malfunctions or failures with the airframe or engine that would have precluded normal operation.

NTSB Probable Cause

The pilot’s flight in dark night conditions with no visual reference and his subsequent spatial disorientation.