N3477PPiper PA-23 · 1958

On June 11, 2022, at 1207 eastern daylight time, a Piper PA-23-180, N3477P, was substantially damaged when it was involved in an accident near Stockbridge, Georgia. The private pilot and pilot-rated passenger were seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot stated he had just purchased the airplane and that it had just undergone an annual inspection. The purpose of the accident flight was for the pilot and the airplane’s previous owner to fly to Covington, Georgia. According to the pilot he conducted a preflight inspection of the airplane and noted no anomalies. The pilot reported that fuel was drained from the main and cross feed fuel lines and was “clean with no water”. He also noted that the fuel was bluish in color similar to 100 low-lead aviation fuel. The pilot stated (and a review of fuel receipts confirmed) that he purchased 43 gallons of 100 low-lead aviation fuel before the flight. The fueler reported the fuel supply was tested twice with negative results for water contamination.

After completing an engine run-up with no anomalies noted, the pilot stated he positioned the airplane as far back on the runway as possible, held the brakes, and applied full power. He stated that he “looked at the engine instruments and all were within the green and producing power,” so he released the brakes for takeoff. After takeoff, the airplane started to shake and yaw to the right, and the pilot believed that the right engine had lost power. The pilot applied left rudder to correct and noted the airspeed was below the placarded blue line airspeed (best rate of climb airspeed for single-engine operation), so he decreased the airplane’s pitch attitude to gain airspeed. He stated, “the airplane was a hand full,” and the pilot then told the pilot-rated passenger to take the controls. The pilot-rated passenger told the pilot to “feather the right engine” and the pilot reported seeing the propeller stop. The pilot-rated passenger then attempted to return to the airport.

The airplane impacted trees, resulting in substantial damage to the fuselage, both wings, both horizontal stabilizers and elevators, and the vertical stabilizer and rudder. The pilot and pilot-rated passenger were seriously injured. A witness reported that upon arriving on scene he smelled a “chemical or fuel like odor in the air.”

Postaccident examination of the airplane was performed under the oversight of a Federal Aviation Administration (FAA) inspector. The inspector reported that all the airplane’s fuel bladders were breached, absent of fuel, and subsequently were unable to be tested for contamination. The fuel selectors were both found positioned to their respective main fuel tank positions, and the cables that connected the selector levers to the selector valves could not be examined due to impact damage.

A postaccident examination of the left engine found there was continuity of the engine crankshaft to the rear accessory drive gears and valvetrain when the crankshaft was rotated by hand. Compression and suction were observed from all four cylinders. No anomalies were noted on the interior of any of the cylinders when examined with a lighted borescope. The induction air box was partially crushed, and the exhaust system was examined with no obstructions noted. Both magnetos remained attached to the engine and produced a spark on all leads when the input drive was rotated by hand. The spark plugs electrodes exhibited normal wear and the No. 1 upper and Nos. 2 and 4 lower spark plugs were oil soaked. The carburetor remained attached to the oil sump and the fuel line from the engine-driven fuel pump to the carburetor was impact separated from the pump but remained attached to the carburetor. The throttle and mixture control cables remained attached to their respective control arms. The carburetor heat control cable was impact-separated from the air box control arm. No liquid was observed in the carburetor float bowl. The carburetor fuel inlet screen was absent of debris and no damage was observed to other carburetor internal parts. The engine-driven fuel pump was fractured across the drive section and the pumping section was impact separated. No anomalies were noted with the engine-driven fuel pump’s internal components. No liquid was observed in the fuel pump or in the corresponding fuel lines forward of the firewall. The oil suction screen and oil filter media were absent of any debris.

Postaccident examination of the left propeller found the propeller remained attached to the engine crankshaft flange and the spinner was impact damaged. The propellers were arbitrarily labeled A and B for identification purposes. Propeller blade A was bent aft about 20° about 10 inches from the tip. Blade A’s tip exhibited impact damage and spanwise scratching. Blade B was bent aft about 45° and exhibited chordwise scratching and trailing edge damage. The propeller control cable remained attached to the governor control arm. The left propeller governor was removed, the drive spline rotated freely by hand, and the governor oil screen was absent of debris.

Postaccident examination of the right engine found engine crankshaft continuity to the rear accessory drive gears and valvetrain when the crankshaft was rotated using the propeller. Compression and suction were observed on all cylinders when the crankshaft was rotated. The interiors of the cylinders were examined with a lighted borescope and no anomalies were noted. The induction air box was impact crushed and the exhaust system was removed with no obstructions noted. Both magnetos remained attached to the engine and the left magneto sparked from all leads when the input drive was rotated by hand. The right magneto did not spark from any lead when the input drive was rotated by hand. Oil was observed on the right magneto distributor block, in the ignition contact points compartment, on the ignition coil, and on the coil high tension contact. The spark plugs exhibited normal wear and the Nos. 2 and 4 upper spark plugs were oil soaked. The carburetor remained attached to the engine oil sump. The aluminum fuel line from the engine-driven fuel pump to the carburetor fuel inlet fitting was impact separated from the pump but remained attached to the carburetor. The throttle control cable remained attached to the throttle control arm. The mixture control cable was impact separated from the carburetor mixture control arm. The carburetor heat control cable was impact separated from the air box control arm. No liquid was observed in the carburetor float bowl and the carburetor fuel inlet screen was absent of any debris. Heavy wear was observed to the rubber tip of the needle in the needle seat assembly. No other damage was observed to the other internal carburetor parts. The engine-driven fuel pump was fractured across the drive section and the pumping section was impact separated. No damage was observed to the pumping section’s rubber diaphragms or check valves. No liquid was observed in either the pump or the corresponding fuel lines forward of the firewall. The oil suction screen and oil filter media were absent of any debris.

Postaccident examination of the right propeller found the propeller remained attached to the engine crankshaft flange and the spinner was impact damaged. The propellers were arbitrarily labeled A and B for identification purposes. No damage was noted to propeller blade A. Propeller blade B exhibited trailing edge damage. The propeller control cable remained attached to the governor control arm. The right propeller governor was removed, the drive spline rotated freely by hand, and the governor oil screen was absent of debris.

At 1026, the weather reported at Hartsfield – Jackson Atlanta International Airport (ATL), Atlanta, Georgia, which was located about 15 nautical miles northwest of the accident site, included a temperature of 29°C and a dew point 17°C. The calculated relative humidity at this temperature and dewpoint was 48 percent. Review of the icing probability chart contained within Federal Aviation Administration Special Airworthiness Information Bulletin CE-09-35 revealed the atmospheric conditions at the time of the accident were "conducive to serious icing at glide [idle] power."