History of Flight
On May 6, 2022, at about 1210 Pacific daylight time, an experimental amateur-built Vans RV-10, registration N54MG, was substantially damaged when it crashed near Sausalito, California. The pilot and passenger were fatally injured. The flight was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The airplane departed Sacramento Executive Airport (SAC) at about 1129 and climbed on a southwesterly heading, leveling off at about 5,500 ft mean sea level (msl). It turned south about 12 minutes later and descended along San Pablo Bay toward San Francisco Bay. At 1151, the pilot contacted air traffic control (ATC), reporting a descent from 4,500 ft to 2,500 ft and indicating he would conduct the “Bay Tour” en route to Half Moon Bay Airport (HAF). ATC instructed the pilot to remain north and west of the Bay Bridge, outside San Francisco Class B airspace, and to advise when he had obtained HAF weather information.
At 1158, the airplane made a 360° right turn around Alcatraz Island, then headed south for about a minute before turning left over Treasure Island. At 1202, it turned southwest after climbing to about 2,400 ft msl and began descending. At 1205, the pilot again expressed his intention to proceed to HAF; ATC again instructed him to remain outside Class B airspace. No further transmissions were recorded. Over the next five minutes, the airplane made a series of turns below 2,100 ft msl near the north end of the Golden Gate Bridge. In the final 40 seconds, at 1209:07, it began a descent from 1,332 ft msl on a westerly heading. At 1209:28, it turned right to a northerly heading while descending from 980 ft msl. The track ended at 1209:47 about 300 ft south of the accident site at an altitude of about 821 ft msl. Airspeed decreased from 79 knots to 63 knots in the final 10 seconds.
Two witnesses located about 0.6 nautical miles east of the accident site reported low visibility and a thick fog layer; one witness could not see the top of the north tower of the Golden Gate Bridge. The bridge towers extend 746 ft above water, and the north tower was about 0.8 nm southeast of the accident site.
The wreckage was discovered by United States Park Rangers at 1403 on the southwest side of a hill in the Marin Headlands at an elevation of about 800 ft msl.
Pilot Information
The pilot used a web-based service to record flight activities from March 16, 2016, to May 12, 2022. According to the record, he flew from Sacramento to HAF on five prior occasions, four in 2021 and one three months before the accident. An entry for the first flight to HAF on January 23, 2021, included: “VFR flight to Half Moon Bay. … Denied entry to Bravo. Flew under Bravo.”
The pilot received his private pilot certificate in November 2020 and began instrument rating training about a month later, but he did not hold an instrument rating at the time of the accident. His flight instructor stated they flew about 40 hours to prepare for the instrument practical test and noted the pilot was proficient in instrument approaches in the accident airplane. The instructor recalled hearing the pilot obtain an instrument clearance without a regular instructor about one year before the accident, which concerned him. Logbook entries from May 17 and 19, 2021, indicated the pilot obtained instrument clearances without a flight instructor onboard. The May 17 entry stated: “fly IFR was in IMC for about 30 min no issue.” The instructor described the pilot as “a little pushy” and accustomed to being “his own boss.”
Meteorological Information
The NTSB conducted a meteorological study using data from the accident flight and surveillance footage. A model sounding showed multiple cloud layers over the accident site from 200 ft above ground level (agl) with tops near 2,800 ft agl, and higher broken clouds at 7,000 ft and 20,000 ft agl. Conditions indicated a high potential for radiation fog and light low-level wind shear at 407 ft msl.
Infrared satellite imagery at 1211 captured low stratiform clouds and/or fog with higher stratiform clouds over the accident site. Weather forecasts issued at 1101 called for mostly cloudy conditions with areas of fog and a chance of showers. A Graphical Forecast for Aviation (GFA) valid at 1100 depicted visibility less than 1 statute mile over the Pacific Ocean and an AIRMET for IFR conditions over the area. A GFA cloud forecast showed broken to overcast clouds with bases near 300 ft and tops 4,000 ft msl. No SIGMETs or Convective SIGMETs were issued.
There was no evidence the pilot obtained weather information from Leidos Flight Service or ForeFlight; although he had a ForeFlight account, he did not view any weather imagery before the flight. He reviewed terminal procedures for his departure and destination airports, which would have included METARs, TAFs, and NOTAMs.
Photographs from Golden Gate Bridge cameras showed dense fog covering the coastline and northern bridge area, with estimated visibility between ¼ and ½ statute mile. A photograph taken by the passenger about 10 to 15 minutes before the accident showed a low band of stratiform clouds near the Golden Gate Bridge and the accident site.
Wreckage Examination
The airplane came to rest in a nose-down attitude on an easterly heading. All major structural components were present at the site. The first point of impact was a depression about 15 ft southwest of the main wreckage, with a debris path of engine cowling and plexiglass fragments leading to the wreckage.
Elevator and rudder flight control continuity was traced from the cockpit to the control surfaces, and aileron continuity was confirmed. Mechanical continuity was established throughout the rotating group, valvetrain, and accessory section when the crankshaft was manually rotated. Thumb compression was achieved at all six cylinders, and borescope examination revealed normal piston face and valve signatures with no indications of catastrophic engine failure.
The two-bladed constant-speed propeller remained attached at the crankshaft flange; both blades were attached to the hub. The spinner was fractured. One blade exhibited chordwise striations, leading edge gouges, trailing edge S-bending, and torsional twisting. The propeller governor and pitch control rod were intact.
The aircraft was not required to have an airplane flight manual; the kit manufacturer provided a stall speed at gross weight without flaps of 64 KIAS.
Medical and Pathological Information
Toxicology testing detected the cannabis metabolite 11-hydroxy-delta-9-THC at 13 ng/mL in the pilot’s urine but not in aortic blood. Carboxy-delta-9-THC, a non-psychoactive metabolite, was found at 3.8 ng/mL in aortic blood and 18.1 ng/mL in urine. Cannabidiol (CBD) and its metabolites were detected. Delta-9-THC (the primary psychoactive compound) was not detected. The FAA considers THC unsuitable for pilots. Rosuvastatin (a prescription cholesterol medication) and famotidine (an over-the-counter stomach medication) were also detected; neither is considered impairing.
The autopsy described the pilot’s heart as hypertrophic and markedly dilated.