ERA15FA362

The pilot's failure to maintain airspeed and her exceedance of the airplane's critical angle-of-attack, which led to an aerodynamic stall, following a total loss of engine power for reasons that could not be determined because postaccident examination of the airframe and engine did not reveal any anomalies that would have precluded normal operation.

The private pilot rented the airplane for a local pleasure flight and departed the airport with full fuel tanks. The airplane had been flying for about 30 minutes and then began a series of turns with its altitude fluctuating between 1,900 and 2,100 ft mean sea level (about 600 to 800 ft above ground level). About that time, one witness reported the engine began "spitting and sputtering" and experienced a total loss of power. Other witnesses reported that the engine stopped, restarted, and then lost power again. The airplane subsequently pitched nose down and entered a spin before ground impact, which is indicative of an aerodynamic stall. Postaccident examination of the airframe and engine did not reveal any evidence of preimpact malfunctions; however, damage to the engine and its associated components precluded a functional check of the engine. Additionally, there were no anomalies noted or reported with the fuel source that would have resulted in a loss of engine power. Although the environmental conditions were favorable for serious carburetor icing at glide power, it is likely the pilot was operating the airplane in cruise flight before the reported engine fluctuations.

An external examination of the pilot, and an autopsy of the passenger were performed by Onondaga County Medical Examiner, Syracuse, New York. The cause of death for both was listed as blunt impact injuries. Forensic toxicology of specimens of the pilot and passenger were performed by the Medical Examiner's Office, and also by the FAA Bioaeronautical Sciences Research Laboratory (FAA), located in Oklahoma City, Oklahoma. The Medical Examiner's toxicology report for the pilot indicated the results were negative for volatiles, carbon monoxide, and tested drugs, while the FAA toxicology report for the pilot indicated the results were negative for carbon monoxide, volatiles, and tested drugs; testing for cyanide was not performed. The Medical Examiner's toxicology report for the passenger indicated the results were negative for volatiles, carbon monoxide, and tested drugs, while the FAA toxicology report for the passenger indicated the results were negative for carbon monoxide and volatiles. Testing for cyanide was not performed and unquantified amount of Ibuprofen was detected in the submitted urine specimen. A weather observation taken at Griffiss International Airport (RME), Rome, New York, at 1253, reported the visibility was 10 statute miles, and few clouds at 3,800 ft. The temperature and dew point were 17 and 7 degrees Celsius respectively, and the altimeter setting was 30.16 inches of mercury. The accident site was located about 22 nautical miles south-southwest from RME. According to a carburetor icing probability chart found in FAA Special Airworthiness Information Bulletin CE-09-35, the temperature and dew point reported at RME about the time of the accident were favorable for "serious icing at glide power." The pilot, age 18, seated in the left seat, held a private pilot certificate with an airplane single-engine land rating issued August 17, 2015. She held a third class medical certificate with no limitations issued October 3, 2013. A review of the pilot's logbook that contained entries from her first logged flight dated August 2, 2013, to her last logged flight dated September 2, 2015, revealed she logged a total time of 130.6 hours, of which 13.9 hours were as pilot-in-command (PIC). Of the 13.9 hours logged as PIC, 1.1 hours were in the accident airplane. In the last 90 and 30 days, she logged 14.1 hours and 3.4 hours, respectively, of which 2.9 hours were in the accident airplane. According to the airplane owner, he flew with the accident pilot in the accident airplane on two separate flights as part of a checkout for insurance purposes. The checkout flights were performed on August 29 and 30, 2015; the flight duration of both was recorded to be 1.8 hours. The flights included practice departure stalls, approach to landing stalls, a power off stall from a left skidding turn, and several simulated engine failures; one of which culminated with a landing to a grass field. The airplane owner indicated that the accident pilot performed all the maneuvers "very well." According to Federal Aviation Administration (FAA) records, the passenger did not hold any pilot certificate. The airplane crashed at the edge of a tree line adjacent to a field. The accident site was located about 310 degrees and 6 nautical miles from the geographic center of VGC. Further inspection of the immediate area revealed a gentle sloped clearing at a higher elevation about 700 feet and 160 degrees from the accident site location. The airplane came to rest with the empennage elevated at a 60 degree angle from the ground. The empennage was lying over both wings, which was oriented on a magnetic heading of 308 degrees. Inspection of the immediate area revealed damage to several tree limbs of an 80-foot tall tree about 30 feet above ground level; the tree limbs were damaged on the northwest side of the tree. The heading from the damaged tree limbs to the main wreckage was approximately 194 degrees. Also located in the immediate wreckage area were tree limbs of varying diameters, none of which exhibited evidence of smooth cuts oriented at a 45-degree angle. All primary and secondary flight controls and structure remained attached or were in close proximity to the main wreckage. No pre or postcrash fire was noted on any component of the wreckage. Examination of the cockpit, which was destroyed by impact revealed the pilot's seat remained attached to the seat tracks at all seat feet positions; the seat lock pin was in the fourth hole from the front, and a safety stop was in place on the inboard seat track. The pilot's lapbelt and shoulder harness remained attached, but the lapbelt webbing was cut. The co-pilot's seat remained attached at the left forward and right aft seat feet positions. The co-pilot's lapbelt and shoulder harness were not buckled. The pilot's control yoke was fractured, while the right horn of the co-pilot's control yoke was fractured. The airspeed indicator, which was separated from the instrument panel indicated 68 mph. The vertical speed indicator was separated from the instrument panel and the needle was separated from faceplate, no needle slap mark was noted. The throttle control was extended 1.75 inches, and the mixture control was fractured at the instrument panel. The carburetor heat control knob was missing and the control was extended 0.50 inch. The tachometer was impact damaged and the needle was missing, no needle slap mark was noted. A needle slap mark on the oil pressure gauge faceplate was noted at the lower end red line radial. The ignition switch was in the both position and the key was inserted but broken. The switch was impact damaged. It was disassembled with no evidence of any preimpact anomalies and subsequently functioned properly in all positions when tested. Examination of the engine primer control revealed the outer nut that secured the primer to panel was separated from the barrel. The primer was impact damaged; however, the knob was in the locked position and was required to be rotated about 180 degrees before it could be unlocked from the outer knurled nut, which was separated. Two cellular phones were recovered and retained for further examination. Examination of the both wings revealed extensive impact damage. Both lift struts remained connected at both ends. Vented fuel caps remained installed on both fuel tanks, which were breached; no stains were noted aft of either fuel tank opening. Residual blue colored fuel consistent with 100 low lead fuel was found in the left fuel tank, while no fuel was found in the right fuel tank. Both flaps and ailerons remained connected; however, impact damage was noted to the left aileron, right flap, and right aileron. One flap cable remained connected to the flap bellcrank near the left flap control surface, but the other cable was pulled from the bellcrank and exhibited tension overload. The right flap pushrod was bent and the rod was fractured at the right flap attach point. The flap motor support was fractured, and the flap jackscrew had no threads extended, which equated to the flaps retracted position. The flap cable exhibited tension overload about 2 ft outboard from the bellcrank. Operational testing of the stall warning horn revealed it did not operate. The internal portion of the wing leading edge was accessed, which revealed the plastic tube remained connected to a portion of the housing, but the housing was fractured. When suction was applied to the portion of housing that was still attached to the plastic tube, the stall warning horn was heard to operate. Examination of the flight control system revealed aileron, elevator, and rudder flight control continuity from the cockpit to each cable where cut for recovery, and from that point to each control surface. The elevator push/pull rod remained connected to the forward bellcrank, but the push/pull rod exhibited "S" type bending and was fractured near the control yoke attach point. Examination of the c