ERA14FA077

The noninstrument-rated pilot's spatial disorientation after inadvertently encountering instrument meteorological conditions at night and his subsequent loss of airplane control.

Before the flight, the pilot obtained weather information for an airport near the departure airport and for an airport about 275 miles south along his route of flight. He did not file a flight plan, did not receive any other services for the accident flight, and departed in night visual meteorological conditions. According to GPS and air traffic control data, the airplane was flying on a southwesterly heading before it turned right. It subsequently turned left and then right before it entered a descending left turn and impacted terrain. Examinations of the airframe and engines revealed no preimpact mechanical malfunctions that would have precluded normal operation. Further, there was no evidence of a medical impairment that would have affected the pilot's performance. A review of the plot's logbooks revealed no entries for night or instrument flight in the year before the accident. A National Weather Service observation from about 15 miles southwest of the accident site showed rapidly changing conditions with a band of snow moving across the region at the time of the accident. In addition, the next observation showed a lowering ceiling that was overcast to broken from 3,200 to 2,800 ft above ground level; snow started falling about 26 minutes after the accident. Considering the weather conditions around the time of the accident, it is likely that the pilot inadvertently encountered instrument meteorological conditions in light snow with no visible surface lights and, as a result, had to transition to relying solely on the instruments. Given these conditions, the pilot's limited instrument and night experience, and the pilot's maneuvering, it is likely that he experienced spatial disorientation and subsequently entered a descending left turn and lost control of the airplane.

Engine Examinations Both engines were examined at Anglin Aircraft Recovery in Clayton, Delaware. They were removed from storage and placed on pallets prior to the investigation team arrival. Upon arrival, the team determined which engine was the left and the right. The examination revealed that there were no mechanical malfunctions or abnormalities that would have precluded normal operation with either engine. A detailed engine examination report for each engine are available in the official docket of this investigation. Electronic Devices A Garmin GPSMAP 696, an iPhone, a Motorola Droid X, and an iPad were found in the main wreckage area, retained, and sent to the National Transportation Safety Board Recorders laboratory for data download. Data was unable to be extracted from the iPhone nor the Motorola Droid X due to impact damage. The Garmin GPSMAP 696 contained data that was recorded at the time of the accident flight. The data began at 0439 and continued until 0528. The last recorded data points indicated that the airplane was on a direct course to DYB, made a slight right turn approximately 45 degrees away from the track toward DYB at 0524. Then, it made a turn back to the left approximately 90 degrees, to the right approximately 90 degrees, and finally, it banked to the left and continued the bank and began a descent until the data points ended. The last data point recorded a ground speed of 141 knots. Spatial Disorientation According to the FAA Airplane Flying Handbook (FAA-H-8083-3), "Night flying is very different from day flying and demands more attention of the pilot. The most noticeable difference is the limited availability of outside visual references. Therefore, flight instruments should be used to a greater degree.… Generally, at night it is difficult to see clouds and restrictions to visibility, particularly on dark nights or under overcast. The pilot flying under VFR must exercise caution to avoid flying into clouds or a layer of fog." The handbook described some hazards associated with flying in airplanes under VFR when visual references, such as the ground or horizon, are obscured. "The vestibular sense (motion sensing by the inner ear) in particular tends to confuse the pilot. Because of inertia, the sensory areas of the inner ear cannot detect slight changes in the attitude of the airplane, nor can they accurately sense attitude changes that occur at a uniform rate over a period of time. On the other hand, false sensations are often generated; leading the pilot to believe the attitude of the airplane has changed when in fact, it has not. These false sensations result in the pilot experiencing spatial disorientation." According to the FAA Instrument Flying Handbook (FAA-H-8083-15), a rapid acceleration "...stimulates the otolith organs in the same way as tilting the head backwards. This action creates the somatogravic illusion of being in a nose-up attitude, especially in situations without good visual references. The disoriented pilot may push the aircraft into a nose-low or dive attitude." The FAA publication Medical Facts for Pilots (AM-400-03/1), described several vestibular illusions associated with the operation of aircraft in low visibility conditions. Somatogyral illusions, those involving the semicircular canals of the vestibular system, were generally placed into one of four categories, one of which was the "graveyard spiral." According to the text, the graveyard spiral, "…is associated with a return to level flight following an intentional or unintentional prolonged bank turn. For example, a pilot who enters a banking turn to the left will initially have a sensation of a turn in the same direction. If the left turn continues (~20 seconds or more), the pilot will experience the sensation that the airplane is no longer turning to the left. At this point, if the pilot attempts to level the wings this action will produce a sensation that the airplane is turning and banking in the opposite direction (to the right). If the pilot believes the illusion of a right turn (which can be very compelling), he/she will reenter the original left turn in an attempt to counteract the sensation of a right turn. Unfortunately, while this is happening, the airplane is still turning to the left and losing latitude. Pulling the control yoke/stick and applying power while turning would not be a good idea–because it would only make the left turn tighter. If the pilot fails to recognize the illusion and does not level the wings, the airplane will continue turning left and losing altitude until it impacts the ground." An autopsy was performed on the pilot on December 27, 2013, by Forensic Pathology Associates, Allentown, Pennsylvania. The autopsy findings included the cause of death as "multiple injuries." Forensic toxicology was performed on specimens from the pilot by the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology report stated no ethanol or drugs were detected in the liver. An observation site from a National Weather Service source for Fountain Dale (RYT), Hamiltonban, Pennsylvania, located approximately 15 miles southwest of the accident site, at the time of the accident, showed rapidly changing conditions during the period with a band of snow moving across the region. The RYT weather observation at 0453 indicated wind from 220 degrees at 3 knots, visibility 10 miles, ceiling overcast clouds at 7,000 feet above ground level (agl), temperature minus 4 degrees C, dew point minus 8 degrees C, and an altimeter setting 30.22 inches of mercury. The RYT weather observation at 0553 indicated wind calm, visibility 10 miles, ceiling overcast at 3,200 feet agl, temperature minus4 degrees C, dew point minus 9 degrees C, and an altimeter setting of 30.21 inches of mercury. The RYT weather observation at 0608 indicated calm wind, visibility 3 miles in light snow, ceiling broken at 2,800 feet, overcast at 7,000 feet, temperature minus 4 degrees C, dew point minus 8 degrees C, and an altimeter setting of 30.20 inches of mercury. In addition, the remarks section stated that snow began at 0556. According to the Astronomical Applications Department at the United States Naval Observatory, the official moonset was at 1224, the official beginning of civil twilight was at 0659, and official sunrise was at 0729. The phase of the moon on the day of the accident was waning crescent, with 38 percent of the moon's visible disk illuminated. A search of Flight Service Station records revealed that the pilot requested weather information and Notice to Airman (NOTAMs) on the day of the accident for Williamsport Regional Airport (IPT), Williamsport, Pennsylvania, and Farmville Regional Airport (FVX), Farmville, Virginia. The pilot did not file a flight plan and did not receive any other services for the accident flight. The weather reported at IPT, which was approximately 27 miles northwest of the departure airport, around the departure time, indicated wind from 090 at 8 knots, visibility 1 ¾ statute mile, light snow, clouds overcast at 2,600 feet agl, temperature minus 4 degrees C, dewpoint minus 7 degrees C. The airplane impacted the ground and came to rest inverted. The wreckage path was oriented on a 179 degree heading and the debris path began about 2,350 feet prior to where the main wreckage came to rest. The main wreckage was oriented on about a 180 degree heading. Several pieces of airframe skin were located in the field leading up to the main wreckage. The first piece of airframe skin was located approximately 2,350 feet prior to the main wreckage. First responders reported an odor similar to 100LL in the field where the main wreckage was located. The nose landing gear was located in the vicinity of and was separated from, the main wreckage. The left and right engines were separated from the main wreckage, embedded in the field, and located approximately 1