Accident Summary
On October 4, 2017, about 1745 eastern daylight time, a Cessna 401B, registration N401HH, was destroyed when it impacted terrain while maneuvering near a private airport in Salters, South Carolina. The commercial pilot and passenger were fatally injured. The airplane was operated by the pilot under Part 91 of the Federal Aviation Regulations. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight, which departed the airport about 1730.
A witness at the airport stated that the airplane took off from the private grass runway. Approximately 10 minutes later, the airplane made a low pass over the runway, then entered a steep climb. The witness reported that the airplane rolled left, the left wing dropped, and it rolled inverted, descending in a nose-low attitude. The airplane then rolled to a level attitude before disappearing behind trees. The wreckage was located in an open field surrounded by trees about 1 mile southwest of the runway.
Another witness, located about 1/2 mile from the end of the runway, reported hearing what sounded like a high-speed pass down the runway. He observed the airplane in a wings-level attitude, then it "snapped a barrel roll." He noted that the airplane rolled wings level over an open field about 100 to 150 yards before the tree line, and he subsequently heard the airplane impact trees. The first witness recorded a cell phone video of the airplane just before impact, consistent with his statement.
Pilot Information
The pilot held a commercial pilot certificate with ratings for airplane single- and multi-engine land, instrument airplane, and rotorcraft-helicopter. He also held an airframe and powerplant mechanic certificate. His most recent Federal Aviation Administration second-class airman medical certificate was issued on July 27, 2017, with the limitation "must have glasses for near vision." At that time, he reported 15,000 total hours of flight experience. The pilot's total flight experience at the time of the accident could not be determined.
Aircraft Information
The six-seat, low-wing, retractable-gear airplane was manufactured in 1969. It was powered by two Continental TSIO-520E, 300-horsepower engines, driving McCauley three-bladed, constant-speed, full-feathering propellers. The most recent annual inspection was completed on August 5, 2017, at 5,557.1 total aircraft hours. The airplane had accrued 9.2 hours since the previous annual inspection on March 25, 2016.
Meteorological Conditions
At 1735, the weather reported at Williamsburg Regional Airport, Kingstree, South Carolina, about 14 miles north of the accident site, included calm wind, 10 statute miles visibility, scattered clouds at 4,700 ft and 6,500 ft, temperature 26°C, dew point 17°C, and an altimeter setting of 30.28 inches of mercury.
Wreckage Examination
The airplane was examined at the accident site, and all major components were accounted for. The wreckage path began in trees about 50 ft above the ground and was oriented on a magnetic heading of about 280°. The main wreckage came to rest inverted on a heading of 230° and was consumed by a postcrash fire. The outboard portion of the left wing was located at the initial tree strike. Fragments of the airframe were found at a second tree strike about 350 ft from the initial strike. The outboard portion of the right wing was located about 320 ft beyond the second tree strike. The main wreckage was about 930 ft from the initial tree strike; the right engine was about 90 ft past the main wreckage. The flaps and landing gear were retracted. Flight control cable continuity was confirmed from all flight control surfaces to the cockpit area, but continuity within the cockpit could not be confirmed due to fire damage. All cockpit instrumentation was destroyed by fire.
The left engine was separated from the nacelle and wing, found inverted by the left wing. All six cylinders remained attached at their bases; cooling fins displayed impact damage. The engine was manually rotated and thumb compression was obtained on all cylinders. A borescope inspection showed that the tops of all pistons and intake and exhaust valves exhibited normal combustion signatures. The propeller separated from the engine at the attachment bolts. The right engine was separated forward of the main wreckage, found inverted and attached to the wing nacelle. All six cylinders remained attached; cylinders Nos. 2, 4, and 6 displayed cooling fin impact damage. The engine was manually rotated and thumb compression was obtained on all cylinders. A borescope inspection revealed normal combustion signatures. The propeller separated from the engine at the propeller flange.
Medical and Toxicology Findings
The Medical University of South Carolina performed an autopsy on the pilot; the cause of death was listed as multiple blunt force injuries. The FAA's Bioaeronautical Sciences Research Laboratory performed toxicological testing, which identified ethanol at 0.185 gm/dl in urine and 0.0210 gm/dl in cavity blood. N-propanol was also found in cavity blood. Additionally, colchicine, 0.122 µg/ml of diphenhydramine, donepezil, acetaminophen, benazepril, naproxen, and rosuvastatin were identified in urine. The report notes that ethanol and diphenhydramine have impairing effects, but no conclusions were drawn regarding their contribution to the accident.