N234PMPiper PA46-500TP · 2005

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.

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.

The accident pilot obtained a preflight weather briefing and filed an IFR flight plan at 0604, with an estimated departure of 0730 for a direct route to LBF at a planned altitude of 16,000 ft msl, with an alternate airport of Lexington, Nebraska. The standard route briefing provided the current hazards as a G-AIRMET for IFR and LLWS conditions extending over the route and accident site. The freezing level was noted between 8,000 and 12,000 ft msl over the route, with no icing expected below 16,000 ft msl. The briefing included Meteorological Aerodrome Report (METARs) for LBF and for other airports along the route from 0353 and 0553, and the TAF issued for LBF at 0832.

The initial TAF for LBF, issued at 0538 and used by the pilot in his preflight weather briefing indicated that MVFR conditions were expected to prevail through 1200 with north-northwesterly winds. After 1200, VFR conditions were expected to prevail with southerly winds gusting to 28 kts. The forecast did not include any forecast for LLWS. The TAF was amended at 0800 with LIFR conditions expected to prevail with an overcast ceiling at 300 ft agl through 1200.

A review of the ASOS observations for LBF indicated that a cold front moved through the area after 0100 and was followed by MVFR ceilings lowering conditions to IFR at 0624, which was after the pilot obtained a preflight weather briefing. At the time of the briefing, LBF was reporting MVFR conditions with the TAF in agreement, with MVFR expected to prevail during the planned flight. LIFR conditions were reported about 40 minutes before the flight’s departure from LNK at 0832 and continued through the time of the accident. Light freezing precipitation was reported intermittently before and after the accident, which was not included in the TAF or other graphic forecasts. The surface temperatures had dropped below freezing 3 hours before the accident and had been above freezing during the night and into the early morning hours, and thus the ground was not frozen and retained some residual heat. The LBF ASOS reported LIFR conditions with overcast ceilings at 300 ft agl and light freezing drizzle at the time of the accident due to below freezing temperatures at the surface.

The High-Resolution Rapid Refresh (HRRR) sounding for 0900 was plotted using the Universal Rawinsonde Observation (RAOB) analysis program. The program indicated a high potential for moderate or greater turbulence between 3,600 and 5,500 ft msl in the inversion where the sounding identified strong wind shear. The National Weather Service (NWS) did not have any current advisories for turbulence and had a G-AIRMET current for LLWS with a 20 kt change in wind speed within 2,000 ft of the surface.

The NWS Graphic Forecast for Aviation (GFA) provides a forecast for the en route phase of flight and for locations without a TAF. The GFA 6-hour forecast issued about 0400 and available at the time of the pilot’s preflight briefing depicted easterly winds at 10 to 15 kts over the region with visibility unrestricted, while a G-AIRMET for IFR conditions extended over the area. The GFA cloud forecast depicted overcast clouds with bases at 3,500 ft msl and tops between 7,000 and 8,000 ft msl.

The NWS AWC CIP about 0600 depicted the potential for light icing over extreme northwest Nebraska and a trace of ice immediately north of the accident site with little to no supercooled large droplets (SLD) expected over the accident site. The NWS AWC 3-hour FIP depicted no icing conditions over the accident site.

During the time period surrounding the accident, the NWS had no SIGMETs, Convective SIGMETs, or Center Weather Advisories (CWA’s) current for the area. The NWS did have G-AIRMETs current for IFR conditions and LLWS below 2,000 ft agl. There were no G-AIRMETs current for icing over the route of flight.

A pilot operating a Cessna 208 for a regional freight carrier from Omaha, Nebraska, to LBF, was following the accident airplane on the instrument approach. The pilot recalled the LBF weather being reported as a ceiling near 200 ft with visibility 1 to 2 miles with occasional freezing rain. He indicated the cloud tops were between 7,500 ft to 7,900 ft with cumulus type clouds and anticipated a turbulent approach with potential icing and a tailwind landing on runway 30. The pilot categorized the approach as “very demanding.” After the accident airplane could not be accounted for in front of him, the pilot made two loops in a holding pattern and then diverted to another airport to the south due to reported light freezing precipitation. The pilot reported that the TAFs he received were somewhat behind the actual reported weather conditions and did not reflect the actual conditions until after 1200. He indicated he thought the front had moved through faster than expected.

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.

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.

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.

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.

On October 29, 2010, about 1611 central daylight time, a Piper Aircraft, Inc. PA-46-500TP, N234PM, was substantially damaged during a forced landing following a loss of engine power while departing Charles R. Johnson Airport (T05), Port Mansfield, Texas. The airline transport pilot and two passengers were not injured. The cross country flight was being conducted under the provisions of 14 Code of Federal Regulations Part 91 with an instrument flight rules flight plan. The flight was originating from T05 at the time of the accident, with Alfred C. Thomas Airport (T69), Sinton, Texas, as the intended destination. Visual meteorological conditions prevailed at the time of the accident.

The pilot stated preflight and run up for takeoff were uneventful. The takeoff roll and departure were normal through gear retraction. Following gear retraction, at about 125 knots, the engine lost power for about 2 seconds. The engine regained power for 3 to 4 seconds and then "lost power again." The pilot flew under power lines and performed a forced landing in a semi open field. During landing the left wing impacted a tree and spun the airplane about 180 degrees, substantially damaging the airplane.

Two postaccident examinations of the wreckage occurred. One took place at the scene of the accident on November 1, 2010, under the supervision of a Federal Aviation Administration inspector. The second took place at a secure storage facility on November 9, 2010, under the supervision of a NTSB investigator. Fuel was noted in the low pressure fuel bowl and the main fuel sump bowl. The fuel appeared clear and free of contaminants. No anomalies were noted with the airframe during either of these inspections. The engine data acquisition unit (DAU) was removed and sent to the NTSB vehicles recorder laboratory for download, and the engine with attached accessories were removed from the airframe and sent to the manufacturer’s facility for examination.

The engine was disassembled and examined under the supervision of a Canadian Transportation Safety Board (TSB) investigator on February 17 and 18, 2011. The engine displayed impact damage, deformation of the exhaust duct, and locally at the gas generator case. The 1st and 2nd stage power turbine guide vane rings displayed circumferential rubbing as a result of making contact with their adjacent components under impact loads. Nothing was noted during the disassembly of the engine that would have precluded normal operation.

The fuel control unit (FCU) was examined externally and tested for operation on a flow bench. The unit met all requirements of a normal Bendix acceptance test with only minor variances attributable to adjustments made during engine set up following installation in the airplane. The fuel control pump was tested separately from the FCU and found to be within normal acceptable limits in both the normal and bypass modes and the inlet screen and outlet filters were both clear of debris or obstructions. The torque limiter, compressor bleed valves, dump and starting solenoid valve, fuel nozzle set, and the fuel oil heater thermovalve all tested within manufacturer’s specifications. The Woodward propeller over-speed governor was tested at an independent facility under the supervision of the NTSB investigator in charge and no anomalies were noted that could have contributed to the accident.

The DAU was downloaded and both channels of the DAU recorded engine condition trend monitoring (ECTM) data events; however, no ECTM events were recorded on the day of the accident.