WPR14FA183

The flight instructor’s failure to arrest the airplane’s descent and maintain clearance from mountainous terrain while maneuvering at a low altitude.

A witness reported that he observed the airplane at an altitude of between 800 to 1,000 ft above ground level about 2 miles from his location. About the same time, he also heard the airplane's engine sputter, and he then observed the airplane in a vertical, nose-down attitude for 3 to 4 seconds before it went out of sight behind a hill. The wreckage was found about 2 hours later in remote mountainous, rocky terrain. An on-site examination of the airframe and engine revealed that the airplane impacted the terrain upright in a flat orientation on a 27-degree downslope. Based on observed impact signatures, the airplane's forward momentum was negligible just before it impacted terrain. All of the components necessary for flight were accounted for at the accident site. Additionally, examinations of the airframe and engine revealed no anomalies that would have precluded normal operation. Based on the witness's observations and the physical evidence observed at the accident site, it is likely that the airplane was in a steep descent at a low altitude and that the flight instructor failed to pull the airplane up and out of the nose-down attitude at a sufficient altitude to preclude impact with terrain.

On May 8, 2014, an autopsy of the right-seat pilot was performed at the facilities of the Office of the Medical Examiner, Utah Department of Health, Salt Lake City, Utah. The results of the examination revealed that the cause of death was attributed to "total body blunt force injuries." Toxicological testing was performed on the right-seat pilot by the FAA's Civil Aeromedical Institute, Oklahoma City, Oklahoma. The results of the testingrevealed no Carbon Monoxide detected in the Blood, no Ethanol detected in the Vitreous, and testing for Cyanide not performed. Additionally, Desmethylsildenafil and Sildenafil (Viagra) was detected in the Blood and Urine. On May 8, 2014, an autopsy of the left-seat pilot was performed at the facilities of the Office of the Medical Examiner, Utah Department of Health, Salt Lake City, Utah. The results of the examination revealed that the cause of death was attributed to "total body blunt force injuries." Toxicological testing was performed on the right-seat pilot by the FAA's Civil Aeromedical Institute, Oklahoma City, Oklahoma. The results of the testing revealed no Carbon Monoxide detected in Blood, no Ethanol detected in Blood, and no testing performed for Cyanide. Additionally, all testing for drugs was negative. An examination of the airframe and engine was conducted at the accident site on May 8, 2014. The examination revealed that the airplane had come to rest on the side of a mountain in an upright position, oriented facing down slope on an incline of about 27 degrees. The airplane's at rest magnetic heading was 350 degrees; a relative impact heading could not be definitively determined. Airframe Examination All major structural components of the airplane were present at the accident site. All control surfaces were observed attached at their relative attach points. Control cable continuity was established throughout the airframe. Cables were observed pinched under the cabin floor. The elevator trim tab was faired, and the elevator trim control was damaged. The flaps were in the retracted position; the flap actuator retracted 0.0" extension. The flap switch was spring loaded to neutral. The throttle was closed, the mixture control was full rich, and the carburetor heat was off. The magneto switch was selected to the BOTH position. The rudder stop Airworthiness Directive had been complied with: Left present and Right separated in the impact sequence. The rudder stop bolts were damaged. The #1 control yoke (left pilot station) was observed to be unremarkable, and the #2 yoke (right pilot station) had separated due to impact forces. The position of the fuel selector was undetermined. Both fuel tanks had been breached (supply line). Both tanks contained fuel, and both fuel caps were serviceable and secured. A survey of the cockpit instrumentation revealed the following: the directional gyro read 060 degrees, the airspeed indicator read 0, and the vertical speed indicator also read 0. The transponder was observed set at squawk code 1200 (VFR). The fuel indicators read empty, and the fuel pressure read 0. The altimeter reading was 2,630 feet, and the pressure was set at 29.78 inHg. The Omni Bearing Selector read 260 degrees, the tachometer read 629.6 hours, and the Hobbs meter read 2,415.0 hours. The examination of the airframe revealed no catastrophic failure that would have precluded normal operation. Engine Examination The engine remained attached to the airframe by the engine mount. The engine had sustained significant impact energy damage at the oil sump and exhaust system. Visual examination of the engine revealed no evidence of pre-impact catastrophic mechanical malfunction or fire. The vacuum pump was removed, and the crankshaft was rotated by hand through the drive pad utilizing a drive tool. The crankshaft was free and easy to rotate in both directions. Thumb compression was observed in proper order on all four cylinders. The top spark plugs were removed and examined, with normal wear observed. The complete valve train was observed to operate in proper order, and appeared to be free of any pre-mishap mechanical malfunction. Normal "lift action" was observed at each rocker assembly. Clean, uncontaminated oil was observed at all four rockerbox areas. Mechanical continuity was established throughout the rotating group, valve train and accessory section during hand rotation of the crankshaft. The combustion chamber of each cylinder was examined through the spark plug holes utilizing a lighted borescope. The combustion chambers remained mechanically undamaged, and there was no evidence of foreign object ingestion or detonation. The valves were intact and undamaged. There was no evidence of valve to piston face contact observed. There was significant ductile bending of the exhaust system components. The left and right magnetos remained securely clamped at their respective mounting pads. The ignition harness was secure at each magneto. Magneto to engine timing could not be ascertained, due to the destruction of the flywheel. The impulse coupler equipped left magneto produced a spark at the end of each spark plug lead (B2 & 4, T1 & 3) during hand rotation of the crankshaft. The right magneto was removed and the drive was found intact and properly safetied. The magneto was observed to produce spark at all four plug leads during hand rotation of the drive. The carburetor bowl was displaced from the carburetor due to the forces of impact. The portion of carburetor that remained attached at the mounting pad was secure. The fracture surface signatures were consistent with overload. The internal float assembly had sustained impact energy damage and had been displaced from the mounting. There was no fuel observed in the float bowl, and no visible contaminates were observed within the carburetor bowl. On site examination of the engine driven fuel pump, fuel lines, and carburetor controls was precluded by the positioning of the airplane and engine at the accident site. The engine fuel system was examined further (post recovery) on July 25, 2014 at the hangar facilities of Above View, Jet Center, St George Airport, Utah. The carburetor sustained impact energy damage, as described previously. The throttle/mixture controls were found securely attached at their respective control arms of the carburetor. The fuel pump was attached to the engine at the mounting pad. The fuel lines remained secure at their respective fittings. The fuel pump cover was removed for examination. The fuel pump remained free of internal mechanical malfunction and obstruction to flow. The diaphragm remained intact. The foam filter element remained securely attached to the airbox bracket. The filter element remained intact and exhibited no evidence of pre-impact obstruction to airflow. The two-bladed, fixed pitch, McCauley propeller remained attached at the crankshaft flange. The spinner was attached to the propeller. The propeller blade tips exhibited minor rotational damage signatures. The examination of the airplane's engine failed to reveal any anomalies that would have precluded normal operation. At 0835, the SGU Automated Weather Observing System (AWOS), located 10 nm southeast of the accident site, reported wind 130 degrees at 4 knots, visibility 10 miles, overcast clouds at 7,000 feet, temperature 12 degrees C, dew point minus 1 degree C, and an altimeter setting of 29.75 inches of mercury. Flight Instructor The flight instructor (CFI), age 75, held an airline transport pilot certificate, with single-engine and multiengine land ratings, and instrument airplane rating, and a flight instructor rating for airplane single-engine, multiengine, and instrument airplane. The instructor's most recent biennial flight review was conducted on October 9, 2013, and his most recent FAA first-class airman medical certificate was issued on June 11, 2013, with no limitations