Incident Overview
On July 17, 2018, at approximately 0830 central daylight time, a Beech V35 airplane, registration N228Q, sustained substantial damage during a forced landing following a loss of engine power near Katy, Texas. The pilot, who was the sole occupant, was not injured. The airplane was registered to Pivot Group LLC and operated by the pilot under Title 14 Code of Federal Regulations Part 91 as a personal flight. The flight originated from Fair Weather Field Airport (TX42) in Monaville, Texas, at about 0820, and was destined for West Houston Airport (IWS) in Houston, Texas. Day visual meteorological conditions prevailed, and the flight was not operated on a flight plan.
Events Leading to the Forced Landing
The pilot reported that a sudden and severe noise and vibration, along with a brief stream of gray smoke from under the right side of the engine cowling, preceded the loss of engine power as he approached the destination airport. He subsequently executed a forced landing to a residential development under construction. The airplane bounced and skidded before coming to rest upright. The fuselage and right wing sustained substantial damage.
Engine Examination Findings
A postrecovery engine examination was conducted under oversight of the National Transportation Safety Board (NTSB) investigator-in-charge. Visual examination revealed two holes in the top of the crankcase near the No. 3 and No. 4 cylinders; the crankcase appeared otherwise intact. A teardown examination determined that the No. 4 connecting rod had separated from the crankshaft journal. The connecting rod remained attached to the piston, and the end of the connecting rod common to the crankshaft was deformed, consistent with secondary mechanical damage. The No. 4 crankshaft journal was discolored consistent with oil starvation. The No. 4 piston was wedged in the cylinder, and portions of the piston skirt had separated. The oil sump contained foreign debris that appeared to be a paper-based shop towel. The oil pickup screen was obstructed by similar debris. Approximately 7 quarts of oil were recovered from the sump in addition to the debris. At the time of the examination, the Hobbs meter indicated 1,414.3 hours, and the tachometer indicated 5,959.54 hours.
Debris Analysis
The debris recovered from the oil sump and pickup screen was forwarded to the NTSB materials lab. Microscopic examination revealed that the debris consisted of a fibrous material with the appearance of a textured paper product similar to paper towels. A sample was washed with acetone to remove engine oil and analyzed using a spectrometer. The cleaned sample displayed a spectrum with a strong match to cellulose, which is found in natural plant fibers such as cotton and wood. Paper products are manufactured with cellulosic material.
Maintenance History
A review of the airplane maintenance records revealed that the most recent annual inspection was completed on September 22, 2017, at 5,815.4 hours tachometer time. On June 6, 2018, the alternator and alternator drive gear were replaced; the corresponding hour meter and tachometer times were 1,390.3 and 5,935.7 hours, respectively. On July 16, 2018, the starter and starter adapter were replaced; the corresponding hour meter and tachometer times were 5,959.33 hours and 1,414.0 hours, respectively. The records contained no subsequent entries.