WPR23FA083

The pilot’s decision to continue visual flight rules flight into instrument meteorological conditions, which resulted in a loss of airplane control due to spatial disorientation.

The pilot departed on a cross-country visual flight rules (VFR) flight on a route with which he was familiar. On the day of the accident, visual meteorological conditions (VMC) prevailed along most of the route; however, the mountain pass just north of the departure airport was obscured by low clouds and light rain. The pilot had obtained weather information before departure that would have reflected the instrument meteorological conditions (IMC), and he would have been able to see the mountain obscuration from the departure airport. Recorded data from onboard avionics revealed that, during previous flights on the accident route, the pilot typically departed and flew direct toward the destination through the mountain pass north of the departure airport, engaging the autopilot shortly after takeoff. The accident takeoff and departure were uneventful, but rather than taking the northern route through the pass as usual, the pilot chose an initial heading to the northeast, toward rising terrain. It is likely that the airplane entered IMC at this point and continued in IMC for the remainder of the flight. The airplane descended as it approached the terrain, and the pilot appeared to make corrective control inputs via the autopilot using the heading mode (HDG) function to turn left back toward the pass. The airplane responded appropriately, and once the airplane had reached the entrance of the pass, the pilot provided a series of small heading corrections toward the north. The airplane then continued on a track similar to previous flights, but veered to the left of the pass, then continued the left turn toward rising terrain. Recorded data indicated that, around this time, power was applied to both engines and the airplane started to climb, likely as a result of the terrain awareness system alerting the pilot to the rising terrain ahead. The airplane then began a series of extreme pitch and bank excursions while climbing and descending in a left turn. The airplane ultimately impacted the ground in a steep left wing- and nose-low attitude. Based on the recorded basic autopilot mode parameters, which included commanded (but not selected) altitude and bank values, the directional commands the pilot issued the autopilot could not be definitively determined; however, it is likely that, based on his use of HDG mode, he was guiding the airplane incrementally through the pass in an effort to avoid terrain and/or inclement weather. The pilot was likely attempting to negotiate the surrounding terrain by reference to the terrain awareness features of the airplane’s integrated flight display (IFD). This feature was not designed to be used as the sole source of navigation. Review of the data during the final stages of the flight indicated that the pilot was most likely disoriented and fighting against the autopilot. The autopilot was equipped with a return-to-level (LVL) safety feature, which can be activated by the pilot at any time. The LVL system works to return the airplane to a straight-and-level flight attitude. About 40 seconds before ground impact, the autopilot was turned off, and LVL mode was activated, likely by the pilot. The autopilot immediately issued commands to regain control, and although it appeared to respond, the descent and roll continued, possibly due to the pilot physically overpowering the autopilot’s control inputs via the control column. Examination of the flight control system did not reveal any anomalies that would have precluded normal operation. The recorded data indicated that both engine power levels mirrored each other during the entire flight, and damage signatures to the engine and propellers were consistent with them both producing power at the time of impact. Damage to the airplane prevented a complete assessment of the operational status of the IFD system; however, the recorded data confirmed that the autopilot was being used throughout the accident flight. The airplane was also equipped with a set of independent backup flight instruments; therefore, the pilot had the capability to disengage the autopilot and fly the airplane by reference to those instruments if needed; however, it could not be determined if he had practiced such procedures before or was current and capable of hand-flying the airplane in IMC. The weather conditions at the accident site were conducive to the accretion of airframe icing, and although the airplane was equipped with deicing equipment, whether it was in use during the flight could not be determined. The system’s operation was not automatic and would have required manual activation by the pilot at regular intervals, which would have represented additional workload and a diversion of his attention as he attempted to maneuver through the terrain. The pilot had no urgent personal activities that would have required him to return that day, but he was aware of the incoming weather system (which persisted for a few days after the accident), and he had a vacation planned for the following week. Returning by car would have resulted in a relatively long drive of over 300 miles. Although the pilot held an instrument rating, no pilot logbooks were available to review, and his recency of instrument flight experience could not be determined. Given his familiarity with the accident route of flight and the isolated nature of the IMC along the route, it is likely that the pilot became overconfident in the airplane’s automation to navigate through the relatively small area of mountain obscuration. The airplane’s erratic pitch and bank excursions just before the accident are consistent with the known effects of pilot spatial disorientation, and the pilot’s susceptibility to the development of spatial disorientation would have increased with a lack of recent IFR flight experience. Based on the available information, it is likely that the pilot’s decision to continue the visual flight rules flight into IMC resulted in his spatial disorientation, a subsequent loss of airplane control, and impact with terrain.

There was no record of the pilot filing an instrument flight rules flight plan or requesting flight following. A pilot who planned to depart SGU on a VFR flight to the SLC area about 1400 on the day of the accident stated that, before departure, he checked enroute weather and the reporting stations all indicated VMC along the route of flight. While on the airport ramp, he observed two airplanes flying in the traffic pattern, yet to the north, he could see clouds obscuring the mountains along his intended route. He considered departing and flying toward the New Harmony area to see if he could travel through the pass, but decided to cancel the flight and drive instead. As he drove through the pass and reached New Harmony, the area was completely enveloped in low clouds. Once he passed through to Cedar City, the cloud bases increased, and visibility was restored to what he considered to be VMC. Surface Observations About the time of the departure and accident, VMC conditions were reported at both the departure and arrival airports, along with airports enroute. Specifically: An Automated Weather Observing Station (AWOS) at SGU about 31 miles south-southwest of the accident site at an elevation of about 2,885 feet, reported at 1456 calm wind, 10 miles visibility, scattered clouds at 4,100 ft agl, a broken layer at 6,500 ft, and light rain. An Automated Surface Observing Station (ASOS) was located at Cedar City Regional Airport (CDC2), which was located along the presumed route of flight, about 14 miles north-northeast of the accident site at an elevation of about 5,620 feet. At 1453, the station reported 11knot wind from 220°, with 10 miles visibility, and few clouds at 12,000 ft agl. During the one-hour period before and after the accident, the SLC ASOS was reporting winds generally out of the south, with few clouds between 6,000 ft and 18,000 ft agl and 10 miles visibility. High-Resolution Rapid Refresh (HRRR) Model Sounding A HRRR model sounding along the airplane’s inbound flight path earlier in the day indicated the potential for few to broken clouds between about 6,300 and 8,500 feet. By 1500, weather conditions had deteriorated, with the model sounding for the accident site identifying clouds in the lower atmosphere from about 6,500 feet (msl) through 9,300 feet with the potential for freezing fog below. The freezing level was noted at about 6,300 feet. The potential for light rime icing was identified below about 8,800 feet, with moderate clear icing identified in about the lowest 100 feet of the atmosphere. Light low-level wind shear was also identified within the lowest 100 feet. The wind nearest the surface was from the south at a magnitude of about 10 knots, but the wind increased in magnitude to a westerly wind of about 30 knots near 15,000 feet. According to Leidos Flight Services (LFS) and its third-party vendors using the LFS system, there was no contact with the accident aircraft on the day of or the day before the accident. The pilot used ForeFlight for flight planning. Data provided by ForeFlight indicated that he had entered the route of flight into the application earlier in the day, and 20 minutes before takeoff he viewed weather imagery, including turbulence, lowest freezing levels, and aviation surface forecasts, along with wind speed forecasts at both the surface and 15,000 ft msl. Previous Flights Data extracted from the airplane’s IFD indicated that the pilot had flown the same route four times from July through to the period leading up to the accident. All flights followed the same general direct track between SGU and SLC. Weather for all those flights indicated VMC prevailed with 10 miles visibility and either clear skies, or few scattered or broken clouds along the route of flight. The flight parameters showed that, for the four previous flights between SGU and SLC, the pilot departed from runway 19 and initiated a climbing left turn onto the downwind leg. About midfield he would engage the autopilot, setting the roll mode to wings level (WL) and the pitch mode to vertical speed (VS). Northeast of the outer limits of St. George, and as he approached the mountain pass to New Harmony, he was usually at an altitude of between 7,000 and 9,500 ft and climbing. He would then switch the autopilot roll mode to either GPS or heading (HDG) as the airplane flew climbed through and out of the pass at altitudes of between 10,000 and 11,500 ft. The airplane would then remain on a direct north-northeast track of about 13° to the SLC area. The drive from SGU to SLC by car would have been about 320 miles and taken between 4 and 5 hours. The pilot held a private pilot certificate with ratings for airplane single- and multi-engine land, and instrument airplane. According to his most recent FAA medical exam, dated February 24, 2022, he reported 2,625 total flight hours, with 50 in the last six months. The pilot’s logbooks were not recovered. Review of data extracted from the airplane’s integrated flight deck (IFD) indicated that most of the flights flown during the year leading up to the accident were direct between SLC and SGU, with some short local flights to airports just north of SLC. According to family members, the pilot was based in Salt Lake City, but had a house in the St. George area, and routinely flew the accident route. The reason for the flight was to check on his house and another construction project in the area. They were not aware of any urgent reason for him to return that day, and although he was planning on leaving for a vacation, it was not until the following week. The pilot’s daughter, who had a pilot’s certificate, stated that he was meticulous with his flight preparation and routinely flew using the autopilot. She stated that the airplane had a well-equipped avionics suite, including terrain awareness and weather. The pilot started flying in the 1990’s, and this was his third Seneca. She was not aware of any issues with the airplane or its autopilot, and while he sometimes flew under instrument flight rules (IFR) and in inclement weather, for the flights between Salt Lake and St George he typically flew under VFR and direct between the two airports. Earlier on the day of the accident, he had mentioned that there was a window in the weather before storms were coming through the area. The airplane was manufactured in 2014 and purchased new by the pilot. It was equipped with a Garmin G1000 IFD, which included a primary and a multi-function display and a GFC 700 Automatic Flight Control System (AFCS) autopilot. The airplane also included an Aspen Avionics EFD1000 primary flight display, configured as a backup system. The Garmin IFD included a synthetic vision system, which displayed terrain and obstacle clearance alerts on the primary screen, along with the topography immediately in front of the airplane. The system provided visual and audible alerts of terrain threats relative to the projected flight path. The G1000 Cockpit Reference Guide specifically stated that the terrain avoidance feature was not to be used as the sole means of navigation and terrain separation, and that it was only to be used as an aid to terrain avoidance. The AFCS included return-to-level (LVL) and Electronic Stability and Protection (ESP) features. When LVL is activated, the autopilot returned the airplane to a wings-level attitude and zero vertical speed. LVL mode was activated by pressing a switch at the top center of the instrument panel and could be activated while the autopilot was engaged or disengaged. Regardless of autopilot status prior to activating LVL Mode, the autopilot would become engaged in the lateral and vertical modes of LVL. Selecting another lateral or vertical mode while LVL was active would activate that mode and cancel the LVL in that axis. ESP functioned only when the autopilot was disengaged. When enabled, ESP provided a control force feedba