CEN12FA154

During a local flight, the pilot contacted an air traffic controller and stated he was returning to his departure airfield. Subsequently, the airplane disappeared from radar, and there was no reported distress call from the pilot or witnesses to the accident. The wreckage was found in an open field. At the time of the accident, visual meteorological conditions prevailed. Impact markings were consistent with the airplane having been in about a 90-degree nose-low attitude when it impacted terrain. An examination of the airframe and engine did not reveal any preimpact anomalies that would have precluded normal operation. An autopsy performed on the pilot noted evidence of an enlarged heart and extensive coronary artery disease. Given this information and the pilot’s history of a left anterior hemiblock, it is likely that the pilot became incapacitated due to a sudden cardiac arrhythmia or acute myocardial infarction.

HISTORY OF FLIGHT On February 10, 2012, about 1240 central standard time, a Cessna 172N, N5427J, impacted terrain near Floresville, Texas. The commercial pilot, the sole occupant, was fatally injured and the airplane was substantially damaged. The airplane was registered to a private individual and operated by Pro Flite Aviation, San Antonio, Texas, under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The local flight originated from the Stinson Municipal Airport (SSF), San Antonio, Texas, at 1222. The pilot received flight following services from air traffic control before radio and radar contact was lost. There were no distress calls made by the pilot and no eyewitnesses to the accident. PERSONNEL INFORMATION The pilot, age 58, held a commercial pilot certificate with airplane multi-engine land and instrument airplane ratings, and a private pilot certificate with an airplane single engine land rating. On October 29, 2011, the pilot was issued a third class medical with the restriction to have glasses available for near vision. On the pilot’s medical application, he reported having accumulated 2,707 hours with 0 hours accumulated in the preceding six months. AIRCRAFT INFORMATION The airplane was a single engine, high wing, fixed landing gear, four seat, Cessna 172N, serial number 17273790, and was manufactured in 1980. It was powered by a normally aspirated, 160 horsepower Lycoming O-320-H2AD engine, serial number L-1174-76T, that drove a McCauley, metal, 2-bladed, fixed pitch propeller. A review of maintenance records revealed that the last annual inspection was accomplished on October 23, 2011, at a total airframe time of 8,268.5 hours. The airplane had accumulated 8,345.4 hours when the pilot checked out the airplane from the fixed base operator (FBO) at SSF. METEOROLOGICAL INFORMATION At 1853, an automated weather reporting facility located at SSF, approximately 15 nautical miles north-northwest of the accident site, reported wind from 330 degrees at 9 knots, 10 miles visibility, few clouds at 2,400 feet, a broken layer at 4,300 feet and an overcast layer at 5,000 feet, temperature 59 degrees Fahrenheit (F), dew point 50 F, and a barometric pressure of 30.17 inches of mercury. COMMUNICATIONS A review of the radio recordings, revealed normal radio communications; the last communication indicated that the pilot was returning to the Stinson Airport. WRECKAGE AND IMPACT INFORMATION The airplane impacted an open field leaving an outline of the airplane’s wings, wing struts, and tires, consistent with an impact of approximately 90 degrees nose low. The main wreckage was located 41.5 feet northeast of the impact markings in a nose low attitude. Both wings displayed symmetric, accordion crushing along their entire length. Both flaps were in the retracted position. The fuel selector was seated in the “both” position. Theempennage was twisted and tore aft of the cabin compartment. The vertical stabilizer and elevators displayed impact damage, but were otherwise unremarkable. Flight control continuity was established from the cockpit control linkage to their respective flight controls. A block of wood was found in the empennage near the flight control cables. The block of wood displayed gouges and rubbing. It was sent for examination at the NTSB laboratories in Washington, D.C. No preimpact anomalies were detected with the airframe. The propeller fractured from the propeller hub. Both blades contained signatures of twisting, polishing, and chord wise scratches. The propeller hub was displaced axially and displayed torsional shearing and rotational smearing of metal surfaces. The gascolator was found destroyed and its screen was found free of obstructions. The engine’s carburetor was disassembled for examination as its throttle plate was found in the full open position. The metal bowl floats were hydraulically deformed and the fuel screen was free of obstructions. The engine’s oil screen was found free of particulates. The oil filter was opened and found free of any large particulates. The magnetos were impact damaged. The cabin heat shroud was removed and disassembled; there was no evidence of carbon monoxide intrusion. Impact damage to the engine prevented rotation of the crankshaft. The cylinders and engine interior were observed with a lighted borescope and no defects were noted. No preimpact anomalies were detected with the engine. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the pilot by the Bexar County Medical Examiner’s Officer. The cause of death was multiple sustained injuries. The manner of death was ruled an accident. The autopsy noted the following findings: Presumed cardiomegaly (430 g cardiac remnant) Severe calcific atherosclerosis, right coronary artery (left coronary system not identified) Forensic toxicology was performed on specimens from the pilot by the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The samples obtained were marked putrefied and not suitable for the testing of carbon monoxide and cyanide. The following were detected in the toxicology: 28 (mg/dL, mg/hg) ETHANOL detected in Muscle 20 (mg/dL, mg/hg) ETHANOL detected in Heart Metoprolol detected in Muscle Metoprolol detected in Kidney Ranitidine detected in Muscle Ranitidine detected in Heart Metoprolol is a beta-blocker used in the treatment of hypertension. Ranitidine is a histamine receptor blocker used in the treatment of gastritis. A review of the pilot’s medical records from his personal physician revealed that he was prescribed Toprol, Hyzaar, ranitidine, and Flomax. He also had a mildly elevated hemoglobin A1C at 6.6%. A review of the pilot’s medical records from his Aviation Medical Examiner (AME) stated that the pilot had annual electrocardiograms (EKGs) performed as part of his first class certification from 2000 to2003. In each EKG, the pilot had a left axis, left anterior hemiblock and a non-specific interventricular conduction delay. This meant the anterior fascicle of the left bundle (or one third) of the electrical system in the ventricles was no longer conducting electricity. TEST AND RESEARCH Wooden Block The dimensions of the block of wood was consistent with an airplane chock. Aged areas of oil soiling were detected on portions of the block. Examination of the block did not reveal any cable patterning or signatures of control cable machining of the block. Damage to the aft bulk head of the airplane likely displaced the wooden block into the empennage area during the impact sequence. Radar Information The pilot remained under radar contact for the accident flight. The radar information recorded the airplane as it traveled to the southeast of SSF. The airplane headed towards a ranch area and flew three complete left hand turns. The airplane then tracked northwest and then north before it flew another left hand turn and then disappeared from radar.