WPR23FA173

The pilot’s exceedance of the airplane’s critical angle of attack and failure to maintain adequate airspeed on short final while operating in adverse wind conditions, which resulted in an aerodynamic stall and impact with terrain.

Nearing the end of a cross-country flight, the pilot entered the airport traffic pattern for a landing at an airport that was surrounded on all quadrants by mountainous terrain. ADS-B data showed the pilot overshot the extended runway centerline when turning onto final approach. On short final the airplane’s airspeed decreased, and surveillance video footage revealed that the airplane’s right wing dropped, followed by a right roll and rapid descent. Subsequent video footage showed the airplane momentarily entered a level attitude, followed by the right wing dropping again. The airplane then entered a roll to the right and a rapid uncontrolled descent until it impacted the ground. The airport’s automated weather observation system (AWOS) indicated that visual meteorological conditions (VMC) prevailed over the accident site, with unrestricted visibility and clear skies. The calculated density altitude at the time of the accident was about 8,200 ft. Weather data revealed thermodynamic and wind profiles that supported mountain wave activity, including updrafts and downdrafts near the accident site. Forecasting models indicated a hydraulic jump across the area at the time of the accident, which implied strong vertical motions that would likely have produced variations in the airplane’s airspeed and the potential for severe to extreme turbulence. A review of the airplane’s performance using ADS-B data and the environmental conditions, including the strong southerly wind at the time of the accident, determined that after the pilot overshot the final approach, he initiated a 20° left turn to rejoin the final approach track. Based on ADS-B heading, altitude, and airspeed data, the increased load factor of the pilot’s right-wing aileron deflection and low airspeed likely exceeded the right wing’s critical angle of attack. The National Weather Service (NWS) issued an urgent weather advisory about 1300, about 30 minutes before the accident flight departed. The urgent advisory identified that the accident site area was expected to encounter wind from the southwest at 25 to 35 mph with gusts to 60 mph. Additionally, the NWS issued a G-AIRMET valid for occasional moderate turbulence below 16,000 ft over the accident site, and advisories for mountain obscuration and strong surface winds immediately bordering the accident site. A search of the FAA-contracted Automated Flight Service Station provider’s records indicated no contact from the pilot for any weather briefing information on the day of the accident. A separate search of ForeFlight weather products indicated that the pilot did not have an account, and no weather briefings or flight plans were filed for the accident airplane on the day of the accident. It is unknown what weather information, if any, the pilot checked or received before or during the accident flight.

A search of the FAA contracted Automated Flight Service Station provider, Leidos Flight Service, records indicated that there was no contact from the pilot for any weather briefing information on the day of the accident. A separate search of ForeFlight weather products indicated that the pilot did not have an account, and no weather briefings or flight plans were filed for N2038Y on the day of the accident. It is unknown what weather information, if any, the pilot checked or received before or during the accident flight. The closest weather reporting facility to the accident site is located at L35, about 0.5 miles west of the accident site. The airport is located east of Big Bear Lake and surrounded by mountainous terrain on all quadrants. Sugarloaf Mountain is located 5 miles south of the accident site at 9,952 ft. The airport had an AWOS, which was not augmented by any human observers and transmitted locally on 135.925 Megahertz (MHz) and broadcast observations to users every 20 minutes. Surrounding the time of the accident the following conditions were reported: At 1355, wind was 11 kts from 240° gusting to 18 kts, visibility 10 statute miles or more, sky clear below 12,000 ft agl, temperature 13° C, dew point temperature -13° C, and altimeter 29.84 inches of mercury (inHg). At 1415, wind was 6 kts from 220° gusting to 19 kts, visibility 10 statute miles or more, sky clear below 12,000 ft agl, temperature 13° C, dew point temperature -11° C, and altimeter 29.84 inHg. While the wind generally prevailed from the southwest during the observations, there were numerous variations of up to 60° in wind direction reported during the period. Multiple pilot reports (PIREPs) were issued before the accident, which reported on the atmospheric conditions that were generally south of the accident site. At 1450 a PIREP from a pilot of a B-737 departing Palm Springs International Airport (PSP) Palm Springs, California, reported the wind from 310° at 27 knots gusting to 36 knots, with a loss of 25 knots of airspeed on departure. There was also a single report of moderate turbulence from a Cirrus SR22 at 12,000 ft about 20 miles to the southwest of the accident site. The NWS issued an urgent weather advisory about 1300. The urgent advisory identified that the accident site area was expected to encounter wind from the southwest at 25 to 35 mph with gusts to 60 mph. Additionally, the NWS issued a G-AIRMET valid for occasional moderate turbulence below 16,000 ft over the accident site, and advisories for mountain obscuration and strong surface winds immediately bordering the accident site. The National Oceanic Atmospheric Administration (NOAA’s) HRRR sounding thermodynamic and wind profiles indicated mountain wave development over the area. NOAA’s Geostationary Operational Environmental Satellites (GOES) imagery indicated localized mountain wave activity with potential updrafts and downdrafts in the vicinity of the accident site at the time of the accident. The FAA published Advisory Circular (AC) 00-57 “Hazardous Mountain Winds and Their Visual Indicators” to assist pilots in diagnosing the potential for severe wind events in the vicinity of mountainous areas. Vertical propagating mountain waves and trapped lee waves were confirmed in the area during the time of the accident. The AC stated that the consequences for a pilot flying through propagating mountain waves include airspeed and altitude deviations and the possible sudden onset of severe or extreme turbulence. Often accompanying these high-altitude effects is the occurrence of very strong surface winds in the form of downslope winds that create a low-level hazard to all aircraft. Further, these extreme low-level winds often terminate abruptly in a hydraulic jump located some distance away from the mountain’s lee slope. The University Corporation for Atmospheric Research WRF Model produced over the region between 1300 through 1500 also depicted conditions favorable for mountain wave activity and a potential hydraulic jump. The “jump” is noted in the horizontal and vertical velocity wind fields and in the streamline analysis as a convergence zone with vortices. The jump region was identified moving across the accident site area about 1300, with strong upward vertical motion of 200-800 fpm followed by downdrafts. According to the pilot’s most recent FAA medical certification, dated May 11, 2022, he self-reported that his civil flight experience included 2,000 total hours of flight experience and 50 hours within the 6 months before the exam. Only one pilot logbook was made available to investigators. A review of available logbook indicated that777.2 hours were forwarded from another source, and it is unknown what type of airplane was flown for those hours. The logbook showed the pilot completed a flight review on September 7, 2019. Although improperly annotated, most pilot logbook entries in the available logbook indicated that the primary aircraft flown by the pilot was the accident airplane. The pilot’s total flight experience as of November 1, 2020, was 983 hours. An aircraft flight log was provided for the accident airplane, with the initial entry dated May 21, 2020, and the last entry dated November 1, 2020. The airplane’s flight log contained a total of seven entries. Two entries dated July 30, 2020, and September 1, 2020, were missing from the airplane’s flight log, but were annotated in the pilot’s logbook. Additionally, the airplane’s flight log indicated that, for a flight on October 23, 2020, the total flight time was 1 hour, but the pilot’s logbook indicated that the total flight time was 3 hours. The airplane’s flight log indicated that the airplane was purchased on January 1, 2020. According to the provided engine, airframe, and propeller maintenance records, the last annual inspection was completed April 2, 2021. The engine logbook indicated that upon completion of the last annual inspection, the tachometer time was 3,666.2 hours, and the time since overhaul was 1,754.62 hours. The airframe logbook indicated that the airframe total time was 3,666.62 hours. The propeller logbook indicated that the time since overhaul was 656.62 hours, and the logbook tachometer time was consistent with the engine and airframe total hours. The San Bernardino County Coroner conducted an autopsy of the pilot’s remains. The autopsy indicated that the cause of death was multiple blunt force injuries, and the manner of death was accident. Toxicology testing performed by the FAA Forensic Sciences Laboratory found no drugs of abuse. The airplane impacted the ground in a nose-down, right bank on a heading of 310° magnetic. The right wing struck the ground, forming the initial point of impact, as confirmed by ground scars that contained fragments of the green position light lens. The right wing created a ground scar about 45 ft long, and a subsequent ground scar was created by the nose of the airplane. The ground scars revealed a pivot point from the nose of the aircraft, followed by a cartwheel motion over to the left wing before the airplane came to rest in a near upright position. Both wings sustained impact damage from the outboard wing section and were fracture-separated near the aileron bellcranks. The right aileron separated from the outboard wing section. The left aileron remained attached to the left outboard wing. The left-wing fuel tank was breached, but the right-wing fuel tank was not breached and contained about 25 gallons of fuel. The engine was partially separated from the fuselage, and the propeller was separated from the engine at the crankshaft. The left flap was observed in the fully extended position. The right flap was observed in the retracted position; however, further investigation revealed that the flap actuator was in the fully extended position, and damage was observed to the flap at the actuator attachment point. The left main and nose landing