History of Flight
On September 7, 2017, at approximately 1400 Pacific daylight time, a Cessna 172N airplane, registered N737QQ, struck trees in Point Reyes National Park near Bolinas, California. The private pilot, who was the sole occupant, sustained fatal injuries, and the aircraft was substantially damaged. The airplane was owned by Sunwest Aviation Inc. and operated by the pilot as a personal flight under Title 14 Code of Federal Regulations Part 91. Marginal visual meteorological conditions prevailed at the time of the accident, and a visual flight rules (VFR) flight plan had been filed. The flight departed Santa Ynez Airport (IZA) at about 1130, destined for Charles M. Schulz-Sonoma County Airport (STS) in Santa Rosa.
According to Federal Aviation Administration (FAA) records, the pilot established radio contact with Northern California Terminal Radar Approach Control (NCT), Seca sector, at 1249 while at 6,500 ft mean sea level (msl), stating his destination. At 1311, the controller assigned an altitude of 6,000 ft msl. Six minutes later, the pilot indicated he would descend below the marine layer. When asked about his intended altitude, the pilot inquired about cloud base heights. The controller could not provide that information, and the pilot stated he would descend to 1,500 ft msl. At 1321, the controller asked if the pilot would follow the shoreline, to which he replied affirmatively at 2,100 ft. At 1325, the Seca sector terminated flight following services, advising that the next sector could not see the aircraft at its current altitude, radar service was terminated, and the pilot was to squawk VFR (1200) and change frequency. The controller suggested contacting the Boulder sector on 133.95 MHz. About 13 minutes later, the Boulder sector received an unintelligible transmission and informed the pilot he could not be heard at that altitude along the coastline, recommending the NCT Approach controller on 135.1 MHz in 15 miles. No further communications were received.
Two Point Reyes National Park employees in a different area of the park reported hearing a loud noise at the time of the accident but did not know its source; both noted dense fog was present. An alert notification was issued by Oakland Air Route Traffic Control Center after radar contact was lost. The airplane's ACK Technologies Inc. E-04 emergency locator transmitter (ELT) activated during the accident sequence, aiding location. The wreckage was found the following day at 1300, approximately 35 miles south-southeast of STS.
Personnel and Aircraft Information
The pilot held a private pilot certificate with a single-engine land rating but no instrument rating. His most recent FAA medical application, dated October 20, 2016, reported 104 hours total flight experience with no hours in the preceding 6 months. He held a third-class medical certificate with a requirement to wear corrective lenses.
According to the airframe logbook, a 50-hour inspection was performed on March 10, 2017, at which time the airplane had accumulated 4,187.37 hours total time and 2,100.9 hours tachometer time; it was found airworthy.
Meteorological Conditions
The nearest official weather station, Gnoss Field Airport (15 miles northeast), reported at 1355: wind 240° at 7 knots, 10 miles visibility, overcast ceiling at 2,600 ft agl, temperature 21°C, dew point 16°C, altimeter 29.99 inHg. The Woodacre remote station (5 miles east-northeast) reported at 1351: wind 240° at 4 mph gusts to 12 mph, temperature 16°C, dew point 15.9°C, relative humidity 99%; at 1451: wind 232° at 4 mph gusts to 8 mph, temperature 16°C, dew point 15.6°C, humidity 98%. The Barnaby station (6 miles north-northeast) reported at 1311: wind 200° at 2 mph gusts to 7 mph, temperature 17.7°C, dew point 16.4°C, humidity 92%; at 1422: wind 180° at 2 mph gusts to 7 mph, temperature 18.3°C, dew point 16.2°C, humidity 88%.
Surface analysis at 1400 showed a trough east of the accident site, with station models depicting cloudy skies. Upper air charts indicated a mid-level trough with onshore wind. A High-Resolution Rapid Refresh model sounding for the accident site at 1400 showed a lifted condensation level at 831 ft msl, convective level at 1,979 ft, and level of free convection at 831 ft; clouds were likely between 831 ft and 4,500 ft msl. GOES-15 satellite data showed cloud cover moving from southwest to northeast, with cloud-top heights of 10,000 ft. AIRMET Sierra warned of mountain obscuration in clouds, precipitation, and mist. An Area Forecast issued at 1245 forecast broken clouds at 1,500 ft msl with tops at 3,000 ft, and by 1400 scattered clouds at 1,500 ft with an additional scattered layer at 14,000 ft. An earlier forecast at 0645 expected overcast at 1,500 ft with occasional 5-mile visibility in mist by 1300.
The pilot received a weather briefing from Leidos the night before, plus three additional briefings on the day of the accident. He filed a flight plan via ForeFlight, which provided the latest METARs, Area Forecasts, AIRMETs, PIREPs, TAFs, and winds aloft. An official DUATS briefing at 1102 also included that information.
Wreckage and Impact Examination
The wreckage was located less than 1 mile northeast of the Pacific Ocean coastline in a densely forested area at an elevation of 646 ft. The left wing separated at the wing root and was suspended from a 60-ft tree; the airplane came to rest inverted about 50 ft away. The outboard left aileron was found near the fuselage; the right wing and flap separated and were suspended from a tree. Flight control continuity was established: aileron interconnect cables were continuous, the left yoke chain engaged, the right yoke fractured but chain loose, elevator cables continuous, rudder cables attached, elevator trim chain broken. The engine and upper instrument panel separated, coming to rest about 50 ft from the main wreckage. The magnetos, vacuum pump, cylinders, and oil sump remained attached; the oil sump had a puncture on the right side. The propeller assembly separated. A fuel receipt indicated 14.6 gallons of 100 low-lead fuel had been added. The carburetor was open with no residual fuel; hydraulic deformation was noted on the brass floats.
An engine examination at Air Transport, Phoenix, Arizona, found top spark plugs with worn-out normal appearance. Rotational continuity and thumb compression were obtained in all cylinders. Borescope inspection revealed no foreign debris. The fuel inlet screen was clear; the oil filter was free of debris. The vacuum pump vanes were intact. Both magnetos were tested: the left produced spark, the right produced intermittent spark initially but after disassembly and functional testing at Champion Aerospace, both were within operating limits with no intermittent output.
Medical Information
The Marin County Sheriff's Office performed an autopsy; the cause of death was multiple blunt impact injuries. Toxicology testing at the FAA Forensic Sciences Laboratory found no carbon monoxide, ethanol, or tested drugs in the pilot's specimens. Cyanide testing was not performed.