ERA11LA103

During initial climb from the airstrip, about 300 feet above ground level, the mechanic/pilot heard a loud noise, followed by a partial loss of engine power. He leveled the nose and verified that the throttle lever was in the full forward position; however, he was unable to maintain altitude. During the subsequent forced landing to a field, the airplane struck a fence. According to the pilot, another pilot who flew the airplane previously reported a rough running engine and had to perform an uneventful precautionary landing to an airstrip. Examination of the wreckage revealed that the No. 2 top spark plug and its associated heli-coil had separated from the cylinder. Further examination revealed that the spark plug and cylinder threads were worn and an approximate 2-inch crack originated near the cylinder head threads. Additionally, the area around the top and bottom spark plug holes exhibited evidence of exhaust gas leakage, which would have most likely been visible during the most recent maintenance inspection. At the time of the accident, the airplane had been operated about 77 hours since its most recent 100-hour inspection, which was completed about 3 months prior to the accident. The No. 2 overhauled cylinder had been operated for 832 hours since it was installed, about 4 years prior to the accident.

On December 31, 2010, about 1400 eastern standard time, a Cessna 152, N28BA, operated by Cirrus Aviation Inc., was substantially damaged during a forced landing after takeoff from Wimauma Airport (FD77), Wimauma, Florida. The certificated private pilot was not injured. The maintenance flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the planned flight to Sarasota/Bradenton International Airport (SRQ), Sarasota, Florida. During a previous flight in the accident airplane, another pilot reported a rough running engine and performed a precautionary landing to FD77. After the landing, the other pilot thought water in the fuel caused the rough running engine. The accident pilot was also an airframe and powerplant mechanic. He advised the other pilot not to attempt to fly the airplane back to SRQ. Rather, the mechanic would fly to FD77 in another airplane and trade airplanes with the other pilot. Subsequently, the mechanic performed a thorough inspection and troubleshooting of the engine and fuel system, and did not find any problems. He also performed a thorough run-up of the engine, with no anomalies noted. The pilot/mechanic then departed FD77. When the airplane was about 300 feet above ground level, the pilot/mechanic heard a loud "bang," followed by a partial loss of engine power. He leveled the nose and verified that the throttle lever was in; however, he was unable to maintain altitude. The pilot/mechanic felt he was too low to return to FD77 and elected to land in a field ahead of the airplane. During the landing, the airplane struck a fence and a pole, slid across a road, and came to rest upright in a ditch. Examination of the wreckage by a Federal Aviation Administration inspector revealed damage to the nose landing gear, firewall, and forward fuselage. The inspector also noted that the No. 2 top spark plug and its associated heli-coil had separated from the cylinder. Further examination revealed that the spark plug and cylinder threads were worn and an approximate 2-inch crack originated near the cylinder head threads. Additionally, the area around the top and bottom spark plug holes exhibited visual evidence of exhaust gas leakage. Review of maintenance records revealed that at the time of the accident, the airplane had accrued approximately 9,858 total tachometer hours and the engine had accrued about 1,955 tachometer hours since major overhaul. The engine was last overhauled on November 15, 2006. The No. 2 cylinder was subsequently removed and replaced with an overhauled cylinder on May 15, 2009, at 1123.4 tachometer hours since the last major overhaul. The engine had been operated for and additional 832 tachometer hours since the replacement of the No. 2 cylinder, until the accident. The airplane's most recent 100-hour inspection was completed on October 8, 2010, and it had been operated for approximately 77 tachometer hourssince that inspection, until the accident.