Beech V35 accident near Katy, Texas, July 17, 2018

The NTSB's narrative final · quoted from the NTSB record

The private pilot reported that, as he approached the destination airport, he noted "a sudden and severe noise and vibration" and "a…stream of gray smoke from under the right side of the [engine] cowling," followed by a loss of engine power. The pilot subsequently conducted a forced landing, during which the airplane sustained substantial damage to the fuselage and right wing. Postaccident engine examination revealed two holes in the top of the crankcase near the Nos. 3 and 4 cylinders. A teardown examination of the engine revealed that the No. 4 connecting rod had failed due to oil starvation, which resulted in a catastrophic engine failure. Foreign debris, which was similar to a paper towel, was recovered from the engine oil sump and the oil pickup screen. Most of the screen area was obstructed by the debris, which had interrupted the oil flow from the sump to the engine. The airplane maintenance records noted that the alternator and alternator drive gear were replaced about 8 weeks before the accident. The engine had been operated about 24 hours since the alternator replacement. The starter and starter adapter were replaced the day before the accident flight. The engine had been operated about 15 minutes since the most recent maintenance work was performed. It is likely that maintenance personnel left the paper towel in the engine during the recent maintenance work, which resulted in oil starvation, the failure of the connecting rod, and the catastrophic engine failure and subsequent total loss of engine power.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.