Accident Details
On November 12, 2018, at approximately 1415 eastern standard time, a Gulfstream American (Aero Commander) 690C, registration N840JC, was substantially damaged during an accident near Myrtle Beach, South Carolina. The commercial pilot sustained serious injuries. The aircraft was being operated as a personal flight under Title 14 Code of Federal Regulations Part 91.
Pilot Account
The pilot reported receiving radar vectors for the downwind leg of the traffic pattern for runway 36 at Myrtle Beach International Airport (MYR). After turning onto final approach and passing the outer marker, the aircraft encountered heavy turbulence. The pilot described what he believed to be a microburst, causing the airplane to descend rapidly. Despite adding full power in an attempt to climb, the aircraft continued descending until it struck the Atlantic Ocean approximately 1 mile from the approach end of runway 36.
Witness Account
A witness observed the airplane appearing "relatively low" and watched it for about 10 seconds before impact. The aircraft impacted the water an estimated 150 to 300 feet from the shore. The witness noted that the airplane was not flying erratically and could not recall hearing engine noise. After impact, the forward fuselage, including the cockpit, separated from the rest of the aircraft. The witness swam out to the wreckage and assisted the pilot to shore.
Weather Conditions
Weather recorded at MYR at 1456 included overcast clouds at 500 feet above ground level (agl), wind from 360° at 10 knots, temperature and dew point both 13°C, and an altimeter setting of 30.16 inches of mercury. Between 1356 and 1456, visibility was restricted likely due to rain or mist, though specific weather phenomena were not reported. Precipitation accumulation was noted in remarks. Rain was officially reported after 1550.
At Grand Strand Airport (CRE), approximately 12 miles northeast, weather at the accident time included wind from 350° at 4 knots, visibility 1½ miles in moderate rain and mist, and an overcast ceiling at 500 feet agl.
Radar Data
Radar imagery showed the accident flight track with the last target at 650 feet mean sea level near the accident site. Base reflectivity echoes of 5 to 15 dBZ extended over the flight track and accident site. No strong reflectivity echoes or gradients indicative of thunderstorms were observed. Radial velocity data did not detect divergent couplets typically associated with microbursts. The NAM sounding wind profile indicated a surface wind from the ENE at 7 knots, veering to south and southwest above a frontal inversion, with wind speeds increasing with height. The sounding supported a high potential for moderate turbulence below 2,000 feet and low-level wind shear in the inversion layer.