History of Flight
On August 3, 2013, about 1254 eastern daylight time, a Beechcraft D55, registration N7641N, was destroyed by impact and fire following a collision with a telephone pole and terrain near Conway, South Carolina. The private pilot and two passengers sustained fatal injuries. The flight departed Conway-Horry County Airport (HYW) at about 1128. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight conducted under 14 CFR Part 91.
According to air traffic control transcripts and radar data, the pilot obtained an instrument clearance and performed a practice Instrument Landing System approach to runway 18 at Myrtle Beach International Airport (MYR) before returning to HYW under visual flight rules. After a low approach at MYR, the airplane climbed to 3,500 feet on a northerly heading. The pilot reported sighting the destination airport, and ATC issued a frequency change. The airplane continued several miles north of HYW and, around 1246, initiated a 180-degree descending turn back toward HYW. At about 1252:50, while descending at a calculated rate of 800 feet per minute, the airplane turned onto the final approach course for runway 22 at HYW.
While tracking inbound, about 2 miles from the runway threshold, the airplane leveled at approximately 600 feet and entered a 270-degree right turn. The last radar target showed an altitude of 700 feet near the accident site. Beechcraft Aerodynamics calculations indicated a right bank of about 30 degrees and airspeeds below 80 knots.
Witnesses reported hearing the airplane approach from the southwest at an extremely low altitude. It then executed a steep right turn, leveled its wings, and began rocking side to side. Departing controlled flight, the airplane struck a telephone pole, rotated about 180 degrees, impacted terrain, and caught fire. One witness described hearing the engine sputtering and stalling, then a sudden increase to full power with the airplane rocking and losing altitude before clipping power lines. Another witness noted no attempt to pull up and heard sputtering, with no landing gear visible.
Personnel and Aircraft Information
The pilot held a private pilot certificate with ratings for single-engine land, multi-engine land, and instrument airplane. His most recent FAA third-class medical certificate was issued February 15, 2012. According to his logbook, he had 354 total flight hours, including 193 hours in the accident airplane make and model.
The six-seat, twin-engine, low-wing, retractable landing gear airplane was manufactured in 1968. It was equipped with two Continental Motors IO-520, 285-horsepower engines. The most recent annual inspection was completed September 10, 2012, at 4,352 total airframe hours. The right and left engines had accrued 1,313 and 135 hours since overhaul, respectively. Main fuel tanks had a capacity of 40 gallons each (37 usable), and auxiliary tanks held 31 gallons each. The fuel systems were interconnected by crossfeed lines, with emergency crossfeed limited to level flight. A one-eighth tank indication corresponded to approximately 5 gallons. The manufacturer's published minimum controllable airspeed (Vmc) for single-engine operation was 80 knots.
Meteorological and Airport Information
The 1255 recorded weather at HYW included wind from 190 degrees at 4 knots, visibility 7 statute miles, scattered clouds at 4,600 and 5,000 feet, temperature 31°C, dew point 23°C, and an altimeter setting of 30.02 inches of mercury.
HYW was a non-towered airport operating under Class G airspace, with an elevation of 35 feet msl and a traffic pattern altitude of 1,035 feet msl. Runway 4/22 was 4,401 feet long and 75 feet wide.
Wreckage and Examination
The accident site was located at the entrance of a residential neighborhood, about 2 miles north of the threshold of runway 22. All major components were accounted for. The airplane impacted terrain in a nose-down attitude of about 25 to 30 degrees at a level attitude, coming to rest on a heading of approximately 305 degrees magnetic. The front cockpit area rested on a brick pillar. The forward carry-through structure was separated, and the outboard half of the left wing was separated. The remainder of the airplane, including the cockpit, cabin, rear fuselage, and empennage, displayed varying degrees of post-impact fire exposure. The engine nacelles were not exposed to fire.
Flight control cables forward of the front carry-through were separated in overstress. The rudder trim actuator extension measured 3.5 inches, corresponding to a tab trailing edge 12 degrees right position. Both elevator trim actuators measured 0.875 inches, corresponding to a tab trailing edge 3 degrees up position. The aileron trim actuator measured 1.625 inches, corresponding to a tab trailing edge 3 degrees down position. The flap handle was in the APPROACH position, but the flaps were observed near retracted. The landing gear selector was down, and the gear was collapsed.
Fuel selector valves indicated the left was selected to left MAIN and the right to right MAIN. The left propeller hub was shattered with all three blades separated, showing tip erosion and curl. The right propeller was separated from the crankshaft flange, with blades slightly bent and no visible tip damage. Both engines showed normal wear and lubrication, with correct crankshaft-to-camshaft timing. Magnetos produced spark, and the right engine-driven fuel pump functioned properly; the left pump could not be tested due to damage. No preimpact mechanical anomalies were identified that would have precluded normal operation.
Medical and Toxicological Information
The Horry County Coroner's Office performed an autopsy on the pilot. Toxicological testing detected desmethylsertraline in the liver and blood and sertraline in the liver and blood. Sertraline is a prescription selective serotonin reuptake inhibitor (SSRI) used for depression, marketed as Zoloft. Desmethylsertraline is a less biologically active metabolite. The pilot had been prescribed medications for depression and anxiety from February 2009 through April 18, 2013; however, on his February 15, 2012 FAA medical application, he marked "no" regarding mental disorders.
Additional Information
A Samsung Galaxy SIII smartphone recovered from the wreckage yielded five videos of the accident flight, time-stamped from 1121:15 to 1244:41. The videos showed engine start, taxi, run-up, and departure. At 1127 during run-up, the left fuel quantity indicator was about one needle-width below half, and the right was about three needle-widths below half. At 1231, on approach to Myrtle Beach at about 300 feet, the left tank showed one needle-width above one-quarter, and the right showed one-eighth (within the yellow range). Radar data indicated the flight continued for another 23 minutes, including a climb to 3,500 feet.
Interpolation of performance charts estimated each engine consumed 27 to 32 gallons during the approximate 90-minute flight, a rate of about 20 gallons per hour. The Pilot Operating Handbook (POH) states that fuel quantity indicators are linked to a selector switch for main or auxiliary tanks; no images of the switch were captured. The POH advises that engine start, takeoffs, and landings be performed on main tanks only and that takeoff not be attempted if gauges indicate the yellow arc or less than 13 gallons in each main tank. The emergency procedure for engine failure after lift-off includes raising landing gear and flaps, closing the throttle on the inoperative engine, feathering the propeller, applying power as required on the operative engine, and maintaining 99 knots until obstacles are cleared. A note emphasizes that if airspeed is below 80 knots, power on the operative engine should be reduced to maintain control.