History of Flight
On April 13, 2024, at approximately 2019 Pacific daylight time, a Gulfstream Corporation 695A airplane, registered N965BC, was destroyed in an accident near San Bernardino, California. The pilot, who was the sole occupant, sustained fatal injuries. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
The pilot had planned to fly from Stockton Metro Airport (SCK) to Chino Airport (CNO) following recurrent training earlier that day. The airplane departed SCK about 1903 and climbed to flight level 250. The cruise portion was unremarkable.
Around 2011, during descent near the FLAVR waypoint, air traffic control (ATC) asked the pilot to confirm he was on the ZIGGY arrival. The pilot affirmed but noted the autopilot had disengaged in turbulence and he was course correcting. ATC cleared him to 12,000 ft msl. About 2012, ATC offered vectors, which the pilot declined, stating he was correcting to join at MAJEK intersection.
At 2014, ATC relayed a PIREP about icing; the pilot reported moderate rime icing. ATC offered a lower altitude, and the pilot accepted. ATC issued a discretionary descent to 8,000 ft msl. At 2016, the pilot indicated icing continued but improved. ATC cleared him to 7,400 ft msl. At 2017, ATC instructed a heading of 185° and advised a lower altitude would be available shortly. The airplane leveled at 7,200 ft msl.
At 2018, ATC updated the altimeter setting to 30.05 inHg. The pilot asked for a repeat and stated he was having autopilot issues. ATC asked if he could turn left; a partial transmission of "...turning..." was received. ATC advised the minimum vectoring altitude was 7,400 ft msl and noted a rapid altitude loss. A low altitude alert was issued. The last ADS-B target was at 2018:47 at 2,600 ft msl.
An Alert Notice was issued about 2035, and the wreckage was located the next day by the San Bernardino County Sheriff's Aviation Unit in steep terrain about 20 miles northeast of CNO, at 2,541 ft msl.
ADS-B data showed the airplane leveled at 7,200 ft msl for 29 seconds, slowed from 124 to 84 kts groundspeed, and began a right turn. The final three data points recorded 6,800 ft msl at 56 kts, 5,200 ft msl at 36 kts, and 2,600 ft msl at 49 kts, respectively.
Pilot Information
The operator estimated the pilot had 3,100 total flight hours, with 950 hours in the previous year. The pilot had been a contract pilot for about 18 months. He completed recurrent training in the accident airplane on the day of the accident, including ground and flight instruction from April 9 to April 13, 2024, totaling about 20 hours. The instructor discussed a return flight plan departing SCK no later than 1830, staying west of specific mountains due to weather, and landing before dark, with overnight options if delayed.
Aircraft Information
The airplane was a Gulfstream 695A, registration N965BC. Maintenance records showed the most recent maintenance on February 15, 2024, including a 12-month/150-hour periodic inspection and reinstallation of the left engine. The aircraft was equipped with a Collins AP 106 autopilot, which does not contain nonvolatile memory.
Meteorological Information
The closest weather reporting facility to the accident site was San Bernardino International Airport (SBD), 9 miles southeast, at 1,159 ft msl. Recorded weather at 2032 included wind from 240° at 15 kts gusting to 23 kts, visibility 4 statute miles, rain, scattered clouds at 800 ft, broken at 1,100 ft, overcast at 2,200 ft, temperature 10°C, dewpoint 6°C, altimeter 30.08 inHg.
The pilot obtained a weather briefing at 1807 via ForeFlight, which included standard forecast information and indicated potential for moderate icing with supercooled large drops likely on descent and near the accident site.
Wreckage and Impact
The airplane impacted mountainous terrain near the top of a 45° sloping ridgeline within a south-facing ravine. Debris dispersed along both sides of the ridgeline. The first identified point of contact was near the top. The debris field on the south-facing slope extended about 260 ft on a magnetic heading of 236°, and on the north-facing slope about 190 ft on 286°. All major structural components exhibited extensive fragmentation and thermal damage. Both engines showed extensive impact damage. Postaccident examination found no evidence of preimpact mechanical malfunction or failure.
Additional Information
The Twin Commander Pilot's Operating Handbook (POH) notes that severe icing may occur outside certification conditions, and ice buildup may degrade performance and controllability. The POH prohibits autopilot use when unusual lateral trim or autopilot trim warnings occur in icing, as it may mask adverse handling changes. Procedures for exiting severe icing include requesting priority handling, avoiding abrupt maneuvers, not engaging the autopilot, and disengaging it if engaged, while reducing angle-of-attack if unusual roll response occurs.
The FAA's Airplane Flying Handbook advises against autopilot use in icing conditions, as it masks trim and handling changes, and sudden disconnection may leave the pilot with unsatisfactory handling characteristics.
Medical and Pathological Information
An autopsy listed the cause of death as multiple blunt impact injuries, manner accident. Toxicology testing detected delta-9-THC at 5.5 ng/g and carboxy-delta-9-THC at 1.8 ng/g in muscle tissue; no blood was available.