CEN10FA316

According to a witness, the non-instrument-rated pilot departed when the weather was overcast at 3,000 feet and the surrounding mountain ridges were obscured. An airport located about 32 miles north of the departure airport, in the direction of travel, was reporting slightly lower ceilings. The pilot requested winds aloft for 3,000 and 6,000 feet, stating, “I need to be at about fifty five hundred probably to be safe,” adding “there’s some three thousand foot tops of some...terrain there in places.” He was likely referring to a mountain range that he would have been approaching about the time of the accident. Thus, the pilot likely intended to climb above the altitude of the reported cloud base, and, therefore, he most likely did enter the clouds. No radar data was available for the flight, and there were no eyewitnesses to the accident; however, a witness reported hearing a low flying airplane followed by the sound of an impact. A postaccident examination revealed that the left wing spar had fractured in upward bending as a result of overload; the bottom cap failed in tension. The examination did not disclose any preimpact mechanical problems with the airplane. Federal Aviation Administration guidance indicates that if neither horizon nor surface references exist, the attitude of an airplane must be determined by artificial means from the flight instruments. Further, during periods of low visibility, the supporting senses sometimes conflict with what is seen; when this happens, a pilot is particularly vulnerable to disorientation. The pilot did not possess an instrument rating, which, coupled with the low visibility as he entered the clouds, would have made him vulnerable to spatial disorientation.

HISTORY OF FLIGHT On June 13, 2010, about 0930 central daylight time, a Piper PA-28-181, N6076H, was substantially damaged when the left wing failed in flight and the airplane impacted terrain approximately 6 miles west of Umpire, Arkansas. Marginal visual meteorological conditions (MVFR) prevailed at the time of the accident. The personal flight was being conducted under the provisions of 14 Code of Federal Regulations Part 91 without a flight plan. The pilot and three passengers on board the airplane were fatally injured. The cross-country flight originated at Helms/Sevier County Airport (DEQ), De Queen, Arkansas, approximately 0915, and was en route to Gaston's Resort Airstrip (3MO), Lakeview, Arkansas. At 0835, the pilot telephoned the Fort Worth, Texas, Automated Flight Service Station and said he needed "a standard or an abbreviated briefing and winds aloft at three and six" thousand feet. The pilot told the briefer that it looked "a little bit iffy" in De Queen and towards the northeast, and he needed to fly at fifty five hundred feet to clear 3,000-foot terrain ahead of him. He said he was more concerned about conditions on his return at 1430 that afternoon. The briefer told the pilot that Mena, AR, located 32 miles north of De Queen, was reporting MVFR conditions. A pilot at DEQ who watched the airplane take off told investigators that the sky was overcast and the surrounding mountain ridges were obscured. There were no witnesses to the accident. A local resident said he heard a low-flying airplane around 0930 and heard the sound of impact. He immediately notified authorities. A medevac helicopter crew located the wreckage approximately 1230. When rescuers arrived at the accident site, they reported a clear but hazy sky. PERSONNEL INFORMATION The pilot, age 45, held a private pilot certificate with an airplane, single-engine, land rating. He was not instrument rated. He also held a third class airman medical certificate, dated January 11, 2010, with no limitations or restrictions. The pilot’s logbook, containing entries December 10, 2009, to June 8, 2010, was found at the accident site. According to the logbook, the pilot had accrued 158.5 hours total time, all but 4.6 hours of which were logged in the Piper PA-28-181. The pilot had received 47 hours of dual instruction. His only instrument time was 4 hours logged under simulated conditions when he was still a student pilot in January and February 2010. AIRCRAFT INFORMATION N6076H (serial number 28-7890161), a model PA-28-181, was manufactured by the Piper Aircraft Corporation in 1977. It was powered by a Lycoming O-360-A4M engine, rated at 180 horsepower, driving a Sensenich 2-blade, all-metal, fixed pitch propeller. The pilot’s daughter found some of the airplane’s maintenance records and gave them to the attorney who handled the pilot’s estate. The attorney made available excerpts of the airplane’s most recent annual and 100-hour inspection. The following is an excerpt from theannual inspection entry, dated September 14, 2009: “Possible crack in left wing on bracket at rear spar visible through inspection plate outer of main gear (left).” The airplane was eventually returned to service and sold to various parties. FAA issued a Letter of Intent to investigate the mechanic’s handling of this inspection (see also TESTS AND RESEARCH). METEOROLOGICAL INFORMATION The following METAR (Aviation Routine Weather Report) was recorded at DEQ at 0920, 5 minutes after the estimated time of takeoff and 10 minutes before the estimated time of the accident: Wind 170 degrees at 3 knots; visibility, 10 statute miles; ceiling, 3,000 feet overcast; temperature, 27 degrees Celsius (C.); dew point, 24 degrees C.; altimeter setting, 30.06 inches of mercury. WRECKAGE AND IMPACT INFORMATION The first point of impact was a large crater containing the buried propeller assembly. The fuselage was lying on its side at the end of the debris field. The right wing was lying next to the fuselage and exhibited leading edge accordion type aft crushing damage. The landing gear was partially attached. The fuel tank was breached, but the cap was in place. The wing tip had separated. The flap and aileron were partially attached and the aileron control cables were pulled out. Several seats lay scattered outside the wreckage. The nose gear lay next to the nose section of the fuselage. Instruments in the instrument panel were destroyed and unreadable. Both control wheels were separated from the instrument panel and were outside the wreckage. Remnants of the stabilator and vertical stabilizer remained partially attached to the fuselage. The vertical fin was twisted and bore leading edge and side impact damage. The rudder was partially attached and was curved at about mid-span with indentations. The rudder stops showed no evidence of flutter. The right outboard portion of the stabilator was located approximately 13 feet aft of the impact crater, and bore no evidence of flutter. The trim tab jack screw exposed 15 threads. According to Piper, 16 is full nose-up trim. Control cable continuity was only partially established. The engine and firewall mounts were in a ground indentation slightly left and to the rear of the fuselage. The crankcase was broken open, revealing the front portion of the crankshaft. The propeller was separated from the crankshaft flange. One blade tip was missing and both blades showed signs of S-bending and twisting. The crankshaft was broken just aft of the number two connecting rod journal. The camshaft was broken at midpoint. A borescope was used to inspect the cylinders. No anomalies noted. The left wing was separated from the fuselage. The main spar had fractured outboard of the attach points. The wing was located inverted in an area about 360 feet southwest of the main wreckage. The separated inboard root section was located 300 feet northwest of the main wreckage. The landing gear remained attached. The flap and aileron withcounterweight were intact. The flap was in the full up position. The aileron control cables were missing and were later located at the fuselage. MEDICAL AND PATHOLOGICAL INFORMATION Autopsies were performed on the pilot (ME-560-10) and the three passengers (ME-558-10, ME-559-10, ME-561-10) by the Arkansas State Crime Laboratory in Little Rock, Arkansas. All four deaths were attributed to “blunt force injuries.” Toxicological tests on the pilot were conducted by FAA’s Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma. According to CAMI’s report, acetone, ethanol, methanol, butanol, and propanol in varying amounts were detected in lung, muscle, and kidney tissue. Putrefaction was noted in the report. Diphenhydramine (an over-the-counter antihistamine with impairing effects) was detected is muscle tissue. No blood was available for testing, and it was not possible for NTSB’s medical staff to estimate when the medication was taken or whether the pilot was impaired. TESTS AND RESEARCH The ends of the left wing main spar were cut off and sent to NTSB’s Materials Laboratory in Washington, DC, for examination. According to the laboratory, the spar fractured in upward bending as a result of overstress. The bottom cap failed in tension. There was no evidence of corrosion. As a result of the entry made for the 2009 annual inspection (see AIRCRAFT INFORMATION), the wreckage was re-examined at the facilities of Dawson Aircraft in Clinton, Arkansas, on November 17, 2010. The forward attachment bracket contained a nut and bolt, but the aft attachment bracket’s nut and bolt were missing. The holes were not elongated. No crack was observed in the left wing rear spar bracket, but a pencil mark was noted on the zinc chromate. ADDITIONAL INFORMATION FAA's Advisory Circular (AC) 60-4A, entitled "Pilot's Spatial Disorientation," states (in part): "The attitude of an aircraft is generally determined by reference to the natural horizon or other visual references with the surface. If neither horizon nor surface references exist, the attitude of an aircraft must be determined by artificial means from the flight instruments. Sight, supported by other senses, allows the pilot to maintain orientation. However, during periods of low visibility, the supporting senses sometimes conflict with what is seen. When this happens, a pilot is particularly vulnerable to disorientation. The degree of disorientation may vary considerably with individual pilots. Spatial disorientation to a pilot means simply the inability to tell which way is 'up.' "The disoriented pilot may place the aircraft in a dangerous attitude..."