PIPER PA-28-181

Full Narrative

On September 4, 2024, about 1930 eastern standard time, a Piper PA-28-181, N512AF, was substantially damaged when it was involved in an accident at Somerset Airport (SMQ), Somerville, New Jersey. The flight instructor was not injured and the pilot receiving instruction received minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.
The flight instructor reported that during a practice landing they saw a group of deer on the runway. He said that they initiated a go-around and during the initial climb he noticed an abnormal engine noise. He stated they were able to climb to about 275 ft above mean sea level before the airplane would no longer climb. He stated the peak engine power was 2,000 rpm and that the airplane’s performance rapidly degraded. He stated the propeller continued to turn; however, no thrust was being produced. The flight instructor reported he took over control of the airplane and made a shallow turn toward the intersecting grass runway. He stated he was able to maneuver the airplane to the edge of the grass runway, but they were over the edge of a tree line when the airplane descended into the trees.
A review of the maintenance records revealed two notable events. A logbook entry dated July 9, 2024, indicated that a pilot reported low oil pressure, rough idle, and an unresponsive throttle. Troubleshooting did not replicate the issues, though the oil pressure was adjusted. Another logbook entry dated August 13, 2024, indicated a pilot reported momentary engine roughness during flight. Troubleshooting after both events found no anomalies, and the issues could not be duplicated.
A Federal Aviation Administration inspector examined the airplane after it was recovered from the accident. During the examination, the inspector noted that the fuel selector was in the left-wing fuel tank position. A continuity check of the fuel system, the left fuel tank, fuel vent, fuel strainer (gascolator) and electric fuel pump revealed no anomalies. A fuel sample taken from the strainer confirmed the presence of 100LL AvGas and was absent of water or debris contamination. The engine was intact, with minimal damage to the propeller and spinner, and no significant defects were observed apart from damage to the exhaust system components consistent with impact.
The throttle control was observed in the full open position and the mixture control was set to full rich. Both the throttle and mixture controls on the fuel control exhibited full, unrestricted motion, with no obstructions identified in the induction system. The engine-driven fuel pump was removed and disassembled, revealing a slight blue residue between the diaphragms, but no other anomalies noted.
After reassembly and reinstallation of the engine-driven fuel pump, the engine was mounted on a test stand with a fuel supply for ground testing. During testing, tests of the magnetos were normal; however, the engine intermittently lost power when the electric fuel boost pump was turned off. With the boost pump on, the engine maintained normal idle power and achieved full rpm at maximum throttle.
The engine’s fuel servo was removed and forwarded by the airplane’s operator to its manufacturer for further examination. According to the operator, the fuel servo exhibited evidence of fuel contamination within the servo. The precise source of the fuel contamination could not be determined. The engine-driven fuel pump was also bench tested with no anomalies noted.