CEN23FA031

The pilot’s flight into low instrument flight rules conditions and turbulence, which resulted in spatial disorientation, loss of control, and an impact with terrain. Contributing to the accident was the pilot’s lack of total instrument experience.

The pilot obtained a preflight weather briefing about 2.5 hours before departing on an instrument flight rules (IFR) cross-country flight. Automatic dependent surveillance-broadcast (ADS-B) and weather data indicated the flight encountered low IFR (LIFR) conditions during the approach to the destination airport. These conditions included low ceilings, low visibility, localized areas of freezing precipitation, low-level turbulence and wind shear. The ADS-B data revealed that during the last minute of data, the airplane’s descent rate increased from 500 ft per minute to 3,000 ft per minute. In the last 30 seconds of the flight the airplane entered a 2,000 ft per minute climb followed by a descent that exceeded 5,000 ft per minute. The last data point was located about 1,000 ft from the accident site. There were no witnesses to the accident. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The airplane’s flight instruments and avionics were destroyed during the accident and were unable to be functionally tested. The rapid ascents and descents near the end of the flight track were consistent with a pilot who was experiencing spatial disorientation, which resulted in a loss of control and high-speed impact with terrain. The pilot purchased the airplane about 3 weeks before the accident and received about 15 hours of transition training in the airplane, including 1 hour of actual instrument conditions during high-altitude training. The pilot’s logbook indicated he had 5.2 hours of actual instrument flight time. At the time of the pilot’s weather briefing, the destination airport was reporting marginal visual flight rules (MVFR) conditions with the terminal area forecast (TAF) in agreement, with MVFR conditions expected to prevail through the period of the accident flight. LIFR conditions were reported about 40 minutes before the airplane’s departure and continued to the time of the accident. Light freezing precipitation was reported intermittently before and after the accident, which was not included in the TAF. The destination airport’s automated surface observing system (ASOS) reported LIFR conditions with overcast ceilings at 300 ft above ground level (agl) and light freezing drizzle at the time of the accident. Low-level turbulence and wind shear were detected, which indicated a high probability of a moderate or greater turbulence layer between 3,600 and 5,500 ft mean sea level (msl) in the clouds. During the approach, the airplane was in instrument meteorological conditions with a high probability of encountering moderate and greater turbulence, with above freezing temperatures. The National Weather Service (NWS) had issued conflicting weather information during the accident time period. The pilot’s weather briefing indicated predominately MVFR conditions reported and forecasted by the TAFs along the route of flight, while both the NWS Aviation Weather Center (AWC) AIRMET (G-AIRMET) and the Graphic Forecast for Aviation (GFA) were depicting IFR conditions over the destination airport at the time of the briefing. The TAFs, G-AIRMET, and Current Icing Product (CIP)/Forecast Icing Products (FIP) were not indicating any forecast for icing conditions or freezing precipitation surrounding the accident time. The pilot reviewed the TAF in his briefing, expecting MVFR conditions to prevail at his expected time of arrival. The TAF was amended twice between the period of his briefing and the time of the accident to indicate IFR to LIFR conditions with no mention of any potential freezing precipitation or low-level wind shear (LLWS) during the period. Given the pilot’s low actual instrument experience, minimal amount of flight experience in the accident airplane, and the instrument conditions encountered during the approach with a high probability of moderate or greater turbulence, it is likely that the pilot experienced spatial disorientation and lost control of the airplane.

A flight instructor who recently provided instruction to the pilot reported that the pilot had purchased the airplane about 3 weeks before the accident. Between October 23, 2022, and October 28, 2022, the instructor and the pilot completed 10 hours of ground instruction and 15.1 hours of flight instruction in the accident airplane. The instructor gave the pilot a low average score at the completion of the training. Between the completion of the training and the accident the pilot had logged 9.4 hours in the accident airplane. The pilot’s logbook, which was in the main wreckage, revealed that the pilot had accumulated 505.3 total flight hours, of which 24.5 hours were in the accident airplane. Of the 505.3 hours, the pilot logged 5.2 hours of actual instrument flight time, of which 1.0 hour was in the accident airplane. The instructor reported the 1.0 hour of actual instrument time in the accident airplane was an encounter with IFR conditions during high-altitude training. The accident airplane was equipped with avionics that included a Meggitt Magic six-screen electronic flight display, a Bendix KMD 850 multi-function display, Meggitt Magic 1500 autopilot/flight director, and a Garmin GNS 430W GPS/WAAS navigation system. The flight instructor noted some discrepancies with the avionics components when he was completing his training with the accident pilot, including coupling an area navigation (RNAV) approach with the autopilot. The accident pilot had planned to complete an avionics upgrade scheduled for January 2023. The instructor recommended the pilot fly only ground-based approaches until the upgraded system was installed. An autopsy of the pilot was performed by Western Pathology Consultants, PC, Scottsbulf, Nebraska, which listed the cause of death as “multiple blunt force injuries.” The Federal Aviation Administration Civil Aerospace Medical Institute Bioaeronautical Sciences Research Branch, Forensic Sciences, performed toxicology testing of postmortem specimens from the pilot. The results were negative for all tests conducted. Postaccident examination of the accident site revealed the airplane impacted terrain on the bank of an irrigation reservoir. A postimpact fire partially consumed the airplane. The main wreckage, which consisted of the engine, fuselage, and empennage, came to rest within the initial impact area. Fragmented airplane structure was located within a 50 ft diameter of the main wreckage. The engine and propeller assembly were embedded in the terrain, followed by the cockpit, cabin, and empennage. The left and right wings came to rest adjacent to the main wreckage (see Figures 3 and 4). The airplane’s flight instruments and avionics were destroyed by impact and thermal damage. The airplane’s landing gear and flaps were in the retracted position. The airplane’s fuel system was destroyed, and there was a fuel odor and fuel sheen on the water surface at the accident location. Figure 3. Aerial view of accident location (Source: Nebraska State Patrol) Figure 4. Accident main wreckage (Source: Piper Aircraft, Inc.) Flight control continuity could not be established due to airplane fragmentation and recovery operations; however, all cable and flight control separations were consistent with the impact sequence or recovery operations. The pitot tube, which was separated from the wing structure, was tested with a slave battery and cables. When battery power was applied to the pitot heat terminals, the tube heated and no anomalies were noted. The engine compressor and turbine module housings displayed torsional deformation, and the compressor blades were all separated at the blade roots. The exhaust tubes exhibited ductile crush damage. The four-blade propeller assembly hub was fragmented. The propeller blades displayed chordwise scratching, leading edge gouging, and twist deformation in the direction of rotation. No preimpact mechanical malfunctions or failures were noted that would have precluded normal operation of the airplane. On November 9, 2022, about 0934 central standard time, a Piper PA46-500TP, N234PM, was destroyed when it was involved in an accident near Bignell, Nebraska. The pilot and passenger sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 business flight. According to air traffic control information, the pilot established contact with Denver Air Route Traffic Control Center (ZDV), reported inbound to the North Platte Regional Airport (LBF), North Platte, Nebraska, and the controller issued the current altimeter setting. The controller asked the pilot for the preferred approach and he requested the instrument landing system (ILS) runway 30 approach. At the request of the pilot, the controller provided vectors to the approach and instructed the pilot to fly to a heading of 230°. The pilot requested to begin the descent, and the controller cleared the pilot to turn right to 280° and descend to 7,000 ft mean sea level (msl). The controller then instructed the pilot to descend to 5,000 ft msl and turn right heading 280°, maintain 5,000 ft msl until established on the ILS, and cleared the pilot for the ILS runway 30 approach. In the same clearance and without receiving a proper read back, the controller instructed the pilot to report the cancellation of his instrument flight plan and change radio frequencies to the LBF common traffic advisory frequency. After a position change with controllers, the relieving controller reported the airplane overdue, and an alert notice (ALNOT) was issued. A review of the ADS-B data revealed that during the last minute of data, the airplane’s vertical descent rate increased from 500 ft per minute to 3,000 ft per minute. In the last 30 seconds, the vertical rate increased to a climb of 2,000 ft per minute, and then sharply decreased to a left descending turn exceeding 5,000 ft per minute. The last data point was located about 1,000 ft west-northwest of the accident site (see Figures 1 and 2). Figure 1. ADS-B flight track view looking east-southeast. Figure 2. ADS-B flight track view looking west-northwest. About 3 miles southeast of LBF, a resident noticed smoke coming from a field and contacted the local fire department. Local authorities responded to the area and reported the airplane accident. There were no witnesses to the accident. The Federal Aviation Administration Civil Aerospace Medical Institute’s publication, “Introduction to Aviation Physiology,” defines spatial disorientation as a “loss of proper bearings; state of mental confusion as to position, location, or movement relative to the position of the earth.” Factors contributing to spatial disorientation include changes in acceleration, flight in IFR conditions, and unperceived changes in aircraft attitude. The FAA’s Airplane Flying Handbook (FAA-H-8083-3C) describes some hazards associated with flying when the ground and horizon are obscured. The Handbook states, in part, the following: Spatial disorientation has been a significant factor in many airplane upset accidents. Accident data from 2008 to 2013 shows nearly 200 accidents associated with spatial disorientation with more than 70% of those being fatal. All pilots are susceptible to false sensory illusions while flying at night or in certain weather conditions. These illusions can lead to a conflict between actual attitude indications and what the pilot senses is the correct attitude. Disoriented pilots may not always be aware of their orientation error. Many airplane upsets occur while the pilot is engaged in some task that takes attention away from the flight instruments or outside references. Others perceive a conflict between bodily senses and the flight instruments and allow the airplane to divert from the desired flightpath because they cannot resolve the conflict. The accident pilot obtained a preflight weather briefing and filed an IFR flight plan at 0604,