Incident Summary
On October 8, 2016, at approximately 1840 central daylight time, a Cessna 150M airplane, registration N704LE, experienced a loss of engine power while en route to Sugar Land Regional Airport (SGR), Texas. The student pilot executed a forced landing to a plowed agricultural field near Beasley, Texas. During the landing roll, the airplane nosed over, resulting in structural damage to the vertical stabilizer, rudder, and left wing. The pilot was not injured.
Aircraft and Flight Details
The airplane was registered to and operated by private individuals under 14 Code of Federal Regulations Part 91 as a solo instructional flight. Visual meteorological conditions prevailed, and the flight was not operated on a flight plan. The flight originated at Wharton Regional Airport (ARM), Wharton, Texas, at about 1610, with an intended destination of Sugar Land Regional Airport (SGR), Sugar Land, Texas.
According to the pilot, he had departed SGR at approximately 1530 and flew to Eagle Lake Airport (ELA) for practice takeoffs and landings. He then proceeded to ARM, where he conducted additional takeoffs and landings and refueled the airplane. A preflight inspection performed at that time revealed no anomalies. After departing ARM, the pilot practiced maneuvers in the local area for about 30 minutes before deciding to return to SGR. While cruising at 2,500 feet mean sea level en route to SGR, the engine began to fail. Engine speed decreased to about 1,500 rpm accompanied by significant vibration. Despite efforts to restore power, the engine lost power completely, prompting the forced landing.
Postaccident Examination
An examination of the engine revealed that the No. 2 cylinder exhaust valve was stuck in the full open position. Disassembly of the cylinder showed carbon deposits on the exhaust valve stem, consistent with the stuck valve condition. No other anomalies were noted in the No. 2 cylinder or the remainder of the engine.
Maintenance History
Maintenance records indicated that the engine was overhauled in April 2002, at which time it had accumulated 3,492 hours total time. The overhauled engine was installed on the accident airplane in May 2002 at a recording tachometer time of 3,291.9 hours. The most recent annual inspection was completed on December 18, 2015. A maintenance entry dated February 26, 2016, noted an exhaust valve leak on cylinder No. 4, which was subsequently replaced. The final entry, dated April 8, 2016, recorded that the No. 2 cylinder spark plugs were cleaned. No subsequent entries were found. At the time of examination, the Hobbs meter indicated 2,373.4 hours and the tachometer indicated 4,131.60 hours.
The engine manufacturer's recommended overhaul interval was 1,800 hours or 12 years. Although more than 14 years had elapsed since the overhaul, Federal Aviation Administration regulations do not require compliance with the manufacturer's time-between-overhaul (TBO) interval.