HISTORY OF FLIGHT On August 13, 2011, about 1200 central daylight time, a 1943 Fairchild M-62 (PT-19A) airplane, N53956, was substantially damaged when it impacted power lines and terrain along the Des Moines River near Madrid, Iowa. The pilot and passenger were fatally injured. The World War II era military training airplane was registered to a private individual. It had been restored and was being operated by the Iowa Aviation Heritage Museum. The personal flight was being conducted under the provisions of 14 Code of Federal Regulations Part 91, without a flight plan. Visual meteorological conditions prevailed for the flight. The flight originated from Boone Municipal Airport (BNW), Boone, Iowa, about 1130. The intended destination was Ankeny Regional Airport (IKV), Ankeny, Iowa. The pilot flew to BNW on the morning of the accident for a fly-in event. During the event, the pilot gave rides to several attendees. The airplane was reportedly refueled prior to departure. The pilot commented that he would be returning to IKV by following the Des Moines River. Witnesses boating on the river reported that they observed the airplane as it flew along the river. As the airplane passed their location, the wings banked apparently waving at them. The airplane was 50 to 100 feet above the river; low enough for the witnesses to notice that the airplane occupants were two men. There was no sign of distress related to the airplane. A witness who was fishing along the shoreline of the river reported that the airplane approached his location from the north. He estimated that the airplane was initially about 500 feet above ground level (agl) and descending. The airplane subsequently struck power transmission lines suspended about 200 feet above the river. The left landing gear and the left wing contacted the static lines. The airplane nosed over approximately three times in-flight and impacted a sandbar along the river, coming to rest inverted. The airplane impacted a sandbar along the Des Moines River, about 3 miles south-southwest of Madrid, Iowa. The site was about 13 miles south of BNW, the departure airport, and about 14 miles northwest of IKV, the intended destination airport. The airplane came to rest inverted. PERSONNEL INFORMATION The pilot held an airline transport pilot certificate with single-engine and multi-engine land airplane ratings. The single-engine rating was limited to commercial pilot privileges. The pilot held type ratings for BE-300, BE-1900, and SA-227 airplanes. The pilot was issued a second class airman medical certificate on August 30, 2010, with a limitation for corrective lenses. On the application for that medical certificate, the pilot indicated "No" to the current use of any prescription or non-prescription medication. He noted a total flight time of 6,600 hours, with 15 hours flown within the preceding 6 months. AIRCRAFT INFORMATION The accident airplane was a 1943 Fairchild M-62 (PT-19), serial number T42-3814. The Fairchild M-62 was a World War II era military training aircraft. It was a single engine, two place, open cockpit, monoplane design, with a conventional (tail wheel) landing gear configuration. The airplane was powered by a 170 horsepower Ranger 6-440-C2 engine. The engine was an in-line, six cylinder, air cooled design. The airplane was purchased by a private individual in December 2002, and was subsequently restored. At the time of the accident, it was being operated by the Iowa Aviation Heritage Museum. The airplane had accumulated approximately 2,560 hours total flight time at the time of the accident. The most recent annual inspection was completed on May 15, 2011, at 2,554 hours. The engine had accumulated about 172 hours since overhaul. There were no subsequent maintenance logbook entries, nor was there any record of unresolved maintenance issues associated with the accident airplane. METEOROLOGICAL INFORMATION The Ames Municipal Airport (AMW) Automated Surface Observing System (ASOS), located approximately 14 miles north east of the accident site, at 1153, recorded weather conditions as: wind from 320 degrees at 14 knots, gusting to 23 knots; scattered clouds at 3,400 feet above ground level (agl); 10 miles visibility; temperature 22 degrees Celsius; dew point 16 degrees Celsius; altimeter 29.98 inches of mercury. The Ankeny Regional Airport (IKV) Automated Weather Observing System (AWOS), located approximately 15 miles southeast of the accident site, at 1155, recorded weather conditions as: wind from 320 degrees at 12 knots, gusting to 18 knots; broken clouds at 3,600 feet agl; 10 miles visibility; temperature 25 degrees Celsius; dew point 14 degrees Celsius; altimeter 29.98 inches of mercury. WRECKAGE AND IMPACT INFORMATION The airplane impacted a sandbar along the river, and came to rest inverted. A section of a static line was located adjacent to the airplane. In addition, two yellow and black spherical power line markers were lying on the sandbar in the vicinity of the accident site. Visual examination of the power transmission lines revealed that one static lines appeared to be down. The second static line and all three transmission lines appeared to be intact. The fuselage was crushed aft to approximately the leading edge of the wings. The nose of the airplane, including the engine, was buried into the sand. The wings were partially separated from the fuselage. The leading edges of the wings were crushed aft. The fuel tanks were partially separated from the wing structure. The flaps and ailerons remained attached to both wings. The empennage was twisted relative to the fuselage. The fuselage structure immediately forward of the empennage was deformed. The vertical stabilizer and rudder were buckled and deformed consistent with an impact at the top of the structures. The rudder was partially separated from the stabilizer. The horizontal stabilizer and elevators appeared intact. Flight control continuity was confirmed. No anomalies consistent with a preimpact failure or malfunction of the airframe were observed. One blade of the two blade wooden propeller was broken off at the hub. The second blade exhibited span wise cracking. Internal engine continuity was confirmed through rotation of the crankshaft. Compression was observed on all cylinders. Both magnetos rotated freely by hand. Ignition spark was obtained across all leads on the left magneto. The right magneto was not equipped with an impulse coupling. No anomalies consistent with a preimpact failure or malfunction of the engine were observed. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy of the pilot was conducted on August 14, 2011, at the Iowa State Medical Examiner's office in Ankeny, Iowa. The pilot's death was attributed to injuries sustained in the accident. The FAA Civil Aerospace Medical Institute (CAMI) toxicology report stated: 20 (mg/dL, mg/hg) Ethanol detected in Vitreous; No Ethanol detected in Muscle; No Ethanol detected in Brain; Desmethylsertraline detected in Liver; Desmethylsertraline detected in Kidney; Sertraline detected in Liver; Sertraline detected in Kidney. Sertraline, also known under the trade name Zoloft, is commonly prescribed for the symptomatic relief of depressive illness. Desmethylsertraline is the predominant metabolite of the antidepressant sertraline. Precise blood levels of the medication could not be established because a blood sample was not available for testing. A review of available medical records revealed that the pilot had been diagnosed with obstructive sleep apnea (OSA). He had been prescribed a continuous positive airway pressure (CPAP) device for the condition. However, it was not possible to determine the extent that OSA induced fatigue might have affected the pilot, if at all, during the accident flight. The pilot's wife stated that her husband was very active and energetic. She noted that there had been several deaths in their family within a relatively short period of time, and that was the most likely reason her husband was taking Zoloft. She believed that he was on a very low dose of the medication. She had not noticed any changes in his behavior prior to the accident. She also reported that her husband had not been using the CPAP device prior to the accident and had not used it at all that summer. She also stated that his snoring was much better, and that he was not exhibiting signs of fatigue prior to the accident.