NTSB Factual Report

HISTORY OF FLIGHT

On June 13, 2014, about 1303 eastern daylight time, an experimental amateur-built 2/3 P-51B/C Mustang, N51BM, was substantially damaged when it impacted terrain shortly after takeoff from Marion County Airport (MAO), Marion, South Carolina. The private pilot was fatally injured. The airplane was registered to and operated by a private individual. Visual meteorological conditions prevailed, and no flight plan was filed for the local and personal flight, which was conducted under the provisions of Title 14 Code of Federal Regulations Part 91.

The pilot's wife reported that the pilot had planned to perform taxi tests in the airplane on the day of the accident, but that he did not intend to fly it. During the pilot's preflight inspection, she observed the pilot sump the fuel tank and activate the fuel pump. After starting the engine, the pilot taxied the airplane to the end of runway 22, and waited about "5 to 6 minutes" for another airplane to depart. The pilot then accelerated down the runway, became airborne about "midfield," and retracted the landing gear. As the airplane climbed, it made a "sharp left turn" and subsequently entered a "nose dive" before disappearing behind trees. Shortly after, she heard the sound of impact. She reported that the engine sound was smooth and continuous through the takeoff and climb.

Another witness observed the pilot complete an engine run up check before he departed and began a "shallow" climb to the south. The witness' view of the airplane was momentarily obstructed, but as the airplane came back into view, he observed it enter a nose-low attitude from about 1,000 feet above ground level, and "dive straight into the ground." The witness also reported that he did not observe any interruptions in power, and stated that it appeared the engine was running normally.

PERSONNEL INFORMATION

The pilot, age 64, held a private pilot certificate that was issued on July 26, 1986, with a rating for airplane single-engine land. The pilot's logbooks were not recovered. His most recent Federal Aviation Administration (FAA) third-class medical certificate was issued on February 2, 2014, at which time he reported 3,933 total flight hours and 22 hours accumulated in the previous 6 months. Additionally, he reported no medical conditions, hospitalizations, medications, or non-aviation related healthcare visits since his previous medical certificate issuance. His medical certificate was issued with the limitation, "must have available glasses for near vision."

According to the pilot's wife, he had accumulated approximately 350 total flight hours in the airplane make and model at the time of the accident.

AIRCRAFT INFORMATION

The airplane was powered by a Ranger 6-440C-5 Series inverted, in-line, 200 horsepower, air-cooled engine, equipped with a 4-blade wooden propeller. According to FAA records, the airplane's airworthiness certificate was issued in September 1980. The airplane was registered to the accident pilot in May 2002.

The airplane logbooks were not recovered; however, a recent maintenance history was constructed from records submitted by a mechanic who completed several owner-assisted inspections with the pilot. The records indicated that the airplane's most recent annual inspection was completed on May 15, 2013 at 786.4 hours total time in service. A recently-overhauled engine was installed and inspected on July 12, 2012 following a gear-up landing.

METEOROLOGICAL INFORMATION

The 1315 recorded weather observation at MAO, included wind from 270 degrees at 8 knots, 10 statute miles visibility, broken clouds at 4700 ft. and 5000 ft., temperature 30 degrees C, dew point 17 degrees C; barometric altimeter 29.87 inches of mercury.

Given the atmospheric conditions present, the density altitude at the time of the accident was calculated as approximately 2,150 feet.

WRECKAGE AND IMPACT INFORMATION

The airplane came to rest in a cornfield about one mile southeast of MAO, and all major structural and flight control components were accounted for at the accident site. An initial impact point (IIP) was identified by several broken corn stalks. The empennage was connected to a portion of the fuselage, which was oriented on a 258-degree magnetic heading. Both wings exhibited aft crush damage along their leading edges, and the wing roots were covered in a black residue that resembled oil. All four propeller blades were separated from the propeller hub; two of the blades came to rest in the debris path, and the other blades were found in the cornfield, one about 80 feet and the other about 6 feet from the main wreckage.

Both ailerons were impact-separated at a bell crank that connected the aileron assemblies to the control stick. The wing flap control tubes were traced from the cockpit to the wing flaps, which could be manipulated by hand. A clevis rod that connected the control tubes to the flap handle separated from the turnbuckle body, which exhibited evidence of shear damage to its internal threads. An examination by the NTSB materials laboratory confirmed that the damage was consistent with mechanical overloading of the rod end from the turnbuckle body. A safety wire that connected the rod end to the turnbuckle also displayed damage consistent with overload. Elevator, rudder, and aileron flight control continuity was traced from the cockpit to each of the respective control surfaces.

The aluminum fuel tanks were breached and an odor of fuel was detected at the accident site. Both fuel tank strainer screens were free of contaminants. Fuel line continuity was traced from the wing tanks through the fuel selector to the fuel line at the engine, which exhibited evidence of overload separation. The fuel selector rotated freely between the right and left tank positions and was not obstructed. The carburetor was not recovered from the accident site.

Engine

Due to impact damage to the crankshaft, the engine crankshaft could not be rotated and internal drive continuity could not be established. The right magneto case displayed impact damage, but the primary leads remained secured to the unit and were continuous to the right side spark plugs. The left magneto was also impact-damaged and several primary leads were severed. The throttle linkage was intact and operable through its full range from the throttle knob to the engine. A portion of the oil hose remained connected to the oil pump and the oil reservoir, which had been breached. A sample taken of the oil within the crankcase appeared clean and free of contaminants. Examination of the crankcase revealed an evenly-distributed presence of oil and no damage other than the bend to the shaft. While a large breach in the oil reservoir was present the internal engine components did not display any indications of lubrication distress, overheating, or oil starvation. Additionally, there was no evidence of internal scoring within the crankcase consistent with a catastrophic engine failure. The carburetor was not recovered from the accident site.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was performed on the pilot by the Medical University of South Carolina, Department of Pathology and Lab Medicine, Charleston, South Carolina. The autopsy report listed the pilot's cause of death as "multiple blunt force injuries."

Forensic toxicology testing was performed on specimens of the pilot by the FAA Bioaeronautical Science Research Laboratory, Oklahoma City, Oklahoma. Testing detected the presence of Zolpidem, a short-acting prescription sleep aid marketed under the trade name Ambien, in the pilot's liver and urine. The test was negative for ethanol.

Medical records obtained from the pilot's primary care physician (PCP) indicated a history of non-insulin-dependent diabetes, hypertension, high cholesterol, and significant heart disease. His heart conditions included arrhythmias, coronary artery disease, and valvular disease. In 1998, the pilot was admitted to the hospital for angina after failing an exercise stress test. A cardiac catheterization revealed stenosis of the proximal left anterior descending coronary artery that involved the large diagonal. In addition, he had gallbladder surgery in 2003. Records also indicated that the pilot underwent quarterly visits to his PCP for many years. Neither these visits nor the pilot's diabetes or heart conditions were ever reported by the pilot on his FAA medical certificate applications.

The pilot's most recent visit to his PCP was on February 27, 2014, three weeks after his last FAA medical certificate examination. At this time his medication list included nitroglycerin sublingual tablets, used to treat symptoms of angina; Mag-oxide, a form of magnesium used to treat low magnesium levels; metformin, used to treat Type II diabetes; Atacand, a blood pressure medication also used for the treatment of heart failure; Lipitor, a cholesterol-lowering agent; aspirin, and Ambien.

A laboratory test was completed during the pilot's most recent examination, which demonstrated a fasting blood sugar of 196 mg/dl (normal is 65-110 mg/dl) and Hemoglobin A1C of 9.4%. Hemoglobin A1C is a measure of the average blood glucose level over the preceding several weeks. Normal Hemoglobin A1C is below 5.6%, diabetes is diagnosed with a Hemoglobin A1C above 6.4%, and good control of diabetes is considered a result less than 7%. No stress tests or other evaluation of the status of his coronary artery disease were present in records from the three years prior to the accident.

NTSB Probable Cause

The airplane's impact with terrain shortly after takeoff due to a physiological incapacitation of the pilot.