CEN13FA078

The airplane was on approach to an unimproved airstrip when it struck power lines and then impacted terrain. The pilot had previously flown into this airstrip but had not done so recently. When the field was previously used as an airstrip, the power lines were buried; however, the power lines had recently been moved above ground. The pilot may not have been aware that the power lines had been moved above ground, and the lines were not marked. The surviving passenger stated that he never saw the power lines before the airplane struck them. The pilot's medical records revealed diagnoses of hypertension, diabetes, high cholesterol, and bipolar disease. Toxicology testing showed the presence of medications consistent with the treatment of these conditions. Although the pilot’s medical records and toxicology results indicated that the pilot had recently stopped taking some medications that could have adversely affected his performance, his bipolar disease would have had significant negative effects on cognition, including memory and executive functioning/judgment, and would have been disqualifying for a medical certification. Therefore, although it is possible that the pilot's underlying psychiatric disease and its treatment may have affected his judgment, it is not possible to determine the extent to which it may have contributed to the accident.

HISTORY OF FLIGHT On November 28, 2012, about 1057 Central Standard Time, a Taylorcraft BC12-D, N94973, struck power lines on approach to an unimproved airstrip in Clutier, Iowa. The pilot was fatally injured and the passenger sustained serious injuries. The airplane was substantially damaged. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a personal flight. Visual meteorological conditions prevailed at the time of the accident, and no flight plan had been filed. The local flight originated from Traer (K8C6) Municipal Airport, Traer, Iowa, at an undetermined time. Witnesses told Tama County Sheriff’s deputies that they saw the airplane flying very slow at treetop level. It flew west then turned south. They didn’t think it was high enough to clear a hill. The airplane then disappeared from their line of sight. The witnesses heard the crash and saw smoke. When Federal Aviation Administration (FAA) inspectors arrived on the scene, the Tama County Sheriff’s Office told them the airplane was on approach to an unimproved airstrip near the intersection of 245th Street and R Avenue. The passenger told first responders that they were “attempting to land.” The passenger told his son they “never saw the wires.” The pilot had flown into this airstrip on previous occasions, but had not done so recently. When the field was used as an airstrip, power lines were buried underground along the approach end of the runway. Recently, however, the lines had been strung up on power poles. It could not be determined if the pilot was aware of the raised power lines. PERSONNEL (CREW) INFORMATION The pilot, age 69, held a private pilot certificate with an airplane single-engine land rating. His expired third class airman medical certificate, dated June 19, 2001, contained the restriction for wearing corrective lenses. At that time, the pilot reported he had logged approximately 700 hours total flight time. The Taylorcraft BC12-D is defined by FAA as a light sport aircraft (LSA). Pilots flying LSAs are only required to possess a valid driver’s license and comply with Title 14 Code of Federal Regulations 61.53(b), which states that no person may act “as pilot in command, or in any other capacity as a required pilot flight crewmember, while that person knows or has reason to know of any medical condition that would make the person unable to operate the aircraft in a safe manner.” AIRCRAFT INFORMATION N94973 (serial number 9373), a model BC-12D, was manufactured by Taylorcraft Aircraft Corporation in 1946. It was a 2-place, high-wing monoplane. The fuselage was constructed of welded steel tubing and covered with fabric. The wings employed braced steel tube struts. It was powered by a Continental C-65-8 engine, rated at 65 horsepower, driving a Sensenich 2-blade, fixed pitch wooden propeller. The airplane’s gross weight was 1,200 pounds. METEOROLOGICAL INFORMATION Weather recorded at 1053 by theMarshalltown (KMIW), Iowa, Automated Surface Observing System (ASOS), located about 26 miles west of Clutier, was as follows: Wind, 220 degrees at 3 knots; visibility, 10 statute miles; sky condition, clear; temperature, 1 degree C. (Celsius); dew point, -4 degrees C.; altimeter, 30.39 inches of Mercury. AERODROME INFORMATION The airstrip had one runway, aligned on a magnetic heading of 136 degrees. It was about 1,760 feet long and 105 feet wide. The field elevation was 999 feet msl (mean sea level). WRECKAGE AND IMPACT INFORMATION The wreckage was located near the threshold of the runway at geographical coordinates 42 degrees, 05.159’ North latitude, and 092 degrees, 26.527 West longitude. The nose of the airplane was aligned on a magnet heading of 261 degrees. Four severed strands of electrical transmission cables extended from the west utility pole to the airplane wreckage and were wrapped around the landing gear, engine, and passenger cabin. Fire had consumed much of the fabric covering back to the empennage. Both wings were consumed by the fire. According to the Grundy County Rural Electric Cooperative, the exact time of the power outage was recorded at 10:57:06. Four wires were severed, interrupting power to 300 residents. The wire type was 000 ACSR (aluminum conduit, steel reinforced), transmitting 12,500 volts. The wires were not marked with orange balls. MEDICAL AND PATHOLOGICAL INFORMATION The passenger succumbed to his injuries on January 6, 2013. Because more than 30 days had elapsed since the accident, his injuries did not meet the definition of “fatal injury” as contained in Title 49 CFR Part 830.2. According to the autopsy report, the pilot’s death was attributed to thermal and blunt force injuries. The report also noted the pilot had severe hypertensive and arteriosclerotic cardiovascular disease and chronic obstructive pulmonary disease. The toxicology report noted the presence of amlodipine, carbamazepine, chlorthalidone, glipizide, losartan, and rosuvastatin in blood and liver. NTSB’s medical officer was consulted. According to her factual report, amlodipine (marketed under the trade name Norvasc), chlorthalidone (marketed under the trade name Thalitone), and losartan (marketed under the trade name Cozaar) are medications used to treat hypertension. Glipizide (marketed under the trade name Glucotrol) is an oral agent used to treat diabetes, and rosuvastatin (marketed under the trade name Crestor) is used to treat high cholesterol. Carbamazepine (marketed under the trade name Tegretol) is used to prevent seizures, treat bipolar disease, and prevent migraine headaches. Examination of the pilot’s personal medical records revealed a diagnosis of hypertension (the pilot had reported controlled hypertension to the FAA), diabetes, high cholesterol, prostate cancer in remission, peripheral vascular disease, and bipolar disease with two psychiatric hospitalizations in the year preceding the crash. The records did not indicate thatcardiac disease had been diagnosed.