History of Flight
On October 1, 2016, at 1310 eastern daylight time, a Culver PQ-14A, N4648V, collided with trees, terrain, and a commercial building during a forced landing after takeoff from Hickory Regional Airport (HKY), Hickory, North Carolina. The commercial pilot was fatally injured, and the airplane was destroyed. The airplane was registered to and operated by the pilot under 14 CFR Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight.
Witnesses and HKY air traffic control tower controllers reported that the airplane's engine stopped producing power during taxi for takeoff. The pilot told the controller he did not know why it quit but restarted the engine. The airplane then departed from runway 24.
Shortly after takeoff, the pilot reported having engine problems and announced his intention to return to HKY. The controller provided the altimeter setting and wind information and cleared the airplane to land on any runway.
Radar data showed the airplane was about 2 miles south of HKY when it reversed course toward runway 01. The radar track ended near the accident site, which was about on the extended centerline of runway 01 and about 1 mile south of the approach end of the runway.
Witnesses near the accident site described the engine sound as sputtering and revving up and down. One witness stated that the airplane would climb slightly when the engine ran and descend when it sputtered. The witness said the airplane disappeared from view and impact sounds were heard.
Personnel Information
The pilot held a commercial pilot certificate with ratings for airplane single-engine land, multi-engine land, and instrument airplane. His most recent FAA third-class medical certificate was issued on October 2, 2014. He reported 2,462 total hours of flight experience at that time.
A review of the pilot's logbook revealed he had accumulated 2,478 total hours at the time of the accident, of which about 400 hours were in the accident airplane. He accrued 7.5 total hours in the year before the accident, including 3.5 hours in the accident airplane.
Aircraft Information
According to FAA records, the airplane was manufactured in 1944. The most recent annual inspection was completed on November 12, 2015, at 744.4 total aircraft hours.
Differences between the airplane's fuel system and the fuel system schematic in the maintenance and operating manuals could not be reconciled.
According to the FAA Fuels Program Branch, a supplemental type certificate (STC) was required to use automobile gasoline in certificated aircraft and engines. An STC was available for the Franklin 6A4-150-B3 engine installed in the airplane, but no STC existed for the Culver PQ-14A airplane. A review of the accident airplane's records found no STC recorded for automobile gasoline.
A line service technician from the fixed base operator at HKY observed the pilot/owner servicing the accident airplane from 5-gallon cans and had never seen the airplane serviced at the FBO.
Meteorological Information
At 1253, the weather at HKY included clear skies, 10 miles visibility, variable wind at 4 knots, temperature 23°C, dewpoint 11°C, and altimeter 30.09 inches of mercury.
According to the New Carburetor Icing-Probability chart by the Australian Transport Safety Bureau, conditions were conducive to serious icing at descent power and moderate icing at cruise power.
Transport Canada publication TP 10737 stated that mogas (automotive gas) is generally higher in volatility than avgas, absorbing more heat when vaporizing, resulting in ice accumulation at higher ambient temperatures, and that the likelihood of carburetor icing while flying on mogas is higher.
According to NTSB Safety Alert 29, engines running on automobile gas may be more susceptible to carburetor icing than those running on avgas.
Wreckage and Impact Information
The wreckage was examined at the accident site on October 2, 2016. A strong odor of automobile gasoline was present, and all major components were accounted for. The wreckage path was oriented 359° magnetic and about 100 ft long. Initial impact was in a tree about 35 ft above ground level, and ground scars were visible in pavement about 25 ft before the airplane came to rest against a building.
The wreckage was divided into three sections: engine and instrument panel, wings and cabin floor structure, and empennage with a nearly intact tail section. All sections remained attached by cabling and wires. Preimpact position of engine controls, including carburetor heat, could not be determined due to impact damage.
Each wing contained three interconnected tanks comprising the main fuel system, plus an auxiliary tank. All six tanks leaked fuel due to impact damage. Continuity of fuel lines was established from tanks to fuel selector, auxiliary fuel pump, and engine through several breaks. The fuel selector was in the main position, and no blockages were found. All drained fuel smelled and appeared like automobile gasoline. Control continuity was established from cockpit to all flight control surfaces.
The propeller remained attached; blades were bent or fractured aft. The engine was separated from wreckage, with impact damage to the No. 5 cylinder and crankcase. The engine was rotated by hand, and continuity was established through the powertrain and valvetrain to the accessory section. Compression was confirmed by the thumb method. The engine could not be rotated through 360° due to a mechanical stop.
The crankcase cover was removed, revealing damage impinging on the No. 5 cylinder and blocking the piston skirt, stopping rotation. Internal components moved smoothly, were well lubricated, and showed no abnormal wear.
The engine-driven fuel pump pumped fuel when actuated with a drill. The hand-driven auxiliary wobble pump also pumped fuel. All fuel screens were absent of debris. The carburetor was disassembled; internal parts moved freely and were undamaged. Metal floats were intact. The carburetor bowl had no debris.
The left magneto produced spark at all terminals when actuated with a drill. The right magneto was impact damaged, with the distributor destroyed; the magneto drive produced spark at the secondary output of the ignition coil.
Medical and Pathological Information
The Office of the Chief Medical Examiner in Raleigh, North Carolina, did not perform an autopsy but completed an external examination, determining the probable cause of death as multiple blunt force trauma.
The FAA Bioaeronautical Sciences Research Laboratory performed toxicological testing on the pilot. Samples tested negative for ethanol. Salicylate (aspirin) was detected in urine.