ERA22FA261 · Piper PA-28RT-201

The pilot was conducting a personal flight with two passengers aboard. Security camera video revealed that when the pilot arrived at the airplane prior to initiating the flight, he did not perform a complete preflight inspection, which should have included at least a cursory examination of the airplane’s engine and a check of the ground below it. Shortly after departure, the pilot declared an emergency, and the airplane made a 180° left turn back toward the airport. The airplane descended and impacted terrain about 1.7 miles from the runway threshold. Postaccident examination of the engine revealed that the crankcase was breached near the No. 4 cylinder. Also, the No. 4 connecting rod journal exhibited thermal damage and bearing material was found welded/smeared to the crankshaft journal. The No. 4 connecting rod cap, connecting rod bolts, and bearing pieces were found in the oil sump along with other metallic debris and a trace amount of oil. Examination of the oil system revealed that the oil pressure sensor was separated from the engine. The sensor’s rigid copper line was fractured at the fitting to the accessory section of the crankcase. The propeller exhibited chordwise scratching and angle-cut tree branches in the vicinity of the wreckage, which were indications that the engine did not lose total power. Examination of the rigid oil pressure line revealed that it fractured due to high-cycle fatigue. This was likely from excessive vibration due to insufficient support of the oil pressure sensor and rigid line. The oil pressure sensor, which was part of the avionics system, was installed about 3 flight hours before the accident. The installation manual for the avionics system stated that a flexible line should be used to install the oil pressure sensor in order to minimize vibration effects. Instead, a rigid line was installed, which would have been more susceptible to the effects of vibration, including high-cycle fatigue failure. Oil staining observed on the ramp area where the airplane was parked before the flight, a trail of oil leading from the parking area to the runway, and the oil observed on the airframe exterior at the accident site all suggest that the airplane was actively leaking oil both before and during the accident flight. Based on all available information, it is likely that the oil pressure sensor line fractured during the flight before the accident flight, which resulted in oil leaking from the engine. This oil leak ultimately resulted in oil starvation and loss of engine power during the departure from, and the pilot’s attempted return to the airport. Had the pilot noted and investigated the source of the oil leakage during the preflight inspection, he might have taken appropriate corrective action and avoided the accident.

Verbatim NTSB analysis and probable cause from the NTSB dataset