History of Flight
On October 18, 2022, at 0741 central daylight time, a Piper PA-32-300, N600JG, was destroyed when it was involved in an accident near Brentwood, Tennessee. The private pilot was fatally injured. The airplane was operating as a Title 14 Code of Federal Regulations Part 91 personal flight. The purpose of the flight was to deliver the airplane to Fayetteville Municipal Airport (YFM), Fayetteville, Tennessee, for an avionics repair. ADS-B data indicated the airplane departed Springfield Robertson County Airport (M91) about 0717 for YFM.
At 0733:40, the airplane was in cruise flight at about 5,400 ft msl heading 180° at 139 knots groundspeed when the pilot declared an emergency due to a partial loss of engine power. The pilot and controller discussed options, and the controller issued a heading of 350° toward Nashville International Airport (BNA). At 0735:50, with the airplane at about 4,800 ft and 109 kts, the pilot reported he could maintain altitude. At 0736:45, at about 4,500 ft, the controller advised BNA was 11 miles ahead and instructed the pilot to proceed to runway 2L. At 0738:25, at about 3,500 ft and 94 kts, the pilot announced the engine was “stopped” and the airplane was “heading down.” The airplane continued northeasterly for about 45 seconds before entering a left descending turn from about 2,700 ft. The final plot showed the airplane at 800 ft heading 205° at 88 kts about 1,800 ft north of the accident site (elevation about 730 ft). A witness described the airplane maneuvering about 75 ft above the ground before impacting wires, crossing the road, and coming to rest in trees. There was no engine noise; only a “whistling” sound. The witness saw fire come from the plane before it fell to the street and exploded.
Personnel and Aircraft Information
The pilot held a private pilot certificate with ratings for airplane single-engine land and instrument airplane. He completed BasicMed requirements on October 21, 2021, declaring 480 total flight hours. His logbook was not recovered; total flight experience was estimated at 505 hours based on time accrued in the year before the accident.
The airplane was a 1969 Piper PA-32-300, powered by a Lycoming IO-540-K1A5, 300-horsepower engine. The most recent annual inspection was completed October 4, 2022, at 3,623.3 total aircraft hours. The engine underwent a field overhaul on October 1, 2012, and had accrued 101.5 hours since.
Meteorological Information
At 0753, the weather at BNA, 7 miles southwest of the accident site, included wind from 310° at 5 knots, 10 miles visibility, few clouds at 5,000 ft, temperature 3°C, dew point -6°C, and altimeter 30.06 inHg.
Wreckage and Impact
The initial impact point was in power lines about 50 ft above the ground. The wreckage path was about 60 ft long, oriented on a magnetic heading of about 180°. The fuselage came to rest upright in the street, rolled partially onto its right side, with the engine and propeller attached. Propeller blades were largely intact with one showing bending consistent with impact. The cockpit, cabin, and tailcone were consumed by post-crash fire. The empennage was fire-damaged but mostly intact. The tail section, left wing, and left main landing gear were suspended in a tree about 45 ft above the fuselage. Flight control cable continuity was confirmed through breaks consistent with impact and thermal damage.
The engine displayed thermal damage but minor impact damage. Attempts to rotate the propeller were unsuccessful. The oil suction screen was removed and completely occluded with debris comprising metallic particles and pieces of rubber material consistent with magneto drive cushion. The No. 6 cylinder connecting rod and crankshaft rod journal were damaged. The crankshaft was fractured at the rear edge of the No. 6 rod journal. The No. 6 rod bearing was extruded. Rusted areas were observed on interior cylinder walls of all six cylinders.
Medical and Pathological Information
An autopsy determined the cause of death as “blunt force injuries and thermal burns.” Toxicological testing detected the antihistamine cetirizine in blood (116 ng/mL) and urine (2286 ng/mL).
Tests and Research
The NTSB examined the crankshaft, connecting rod assemblies, No. 6 piston and cylinder, bearings, debris, oil screen, oil seal, and exemplar magneto bumpers. The crankshaft was fractured through the No. 6 connecting rod journal adjacent to the forward cheek. The No. 6 connecting rod was fractured near the small end. The crankshaft was marked LW-10842, indicating it was a Lycoming part that had been ground undersize. According to engine manufacturer representatives, crankshaft LW-10842 was made obsolete in 1979 and was certified for use in multiple IO-540 variants, but the list did not include the accident engine model, IO-540-K1A5.
Main bearings were FAA PMA bearings with part numbers consistent with the engine using a crankshaft with 0.006-inch undersize main journals. The babbitt material was intact with isolated debris and drag marks. Coked oil deposits were present on bearing backs. Edges of oil channel holes were deformed on bearings M4 and M5, consistent with contact with dowels. The crankshaft fracture surface revealed a fatigue crack initiating at the fillet radius between the No. 6 connecting rod journal and forward cheek. Similar cracks were observed with features consistent with excessive loads from contact between connecting rods and engine case.
Sliding contact damage was observed on cheeks and connecting rod caps. The oil filter screen was occluded with material consistent with a magneto bumper, but no evidence of general oil starvation was found. Signatures of localized oil starvation at the No. 6 connecting rod bearing were consistent with oil interruption from fatigue crack propagation.
The replacement crankshaft installed during the 2012 overhaul had been renitrided. Examination revealed case depth greater and core hardness lower than specified in engineering drawings. Connecting rod bearings were eligible for use in multiple variants but not the accident engine. The connecting rod in the No. 4 position was labeled 3, and the one in the No. 3 position was labeled 4. Outer surfaces of connecting rods showed evidence of contact with the engine case.