History of Flight
On September 18, 2012, about 1532 mountain daylight time, a Piper PA-46-350P, registration N188SR, made a forced landing in a field near Kiowa, Colorado, following a loss of engine power. The pilot, the sole occupant, was not injured. The airplane sustained substantial damage. The aircraft was operated by a private individual under 14 CFR Part 91 as a ferry flight. Visual meteorological conditions prevailed, and no flight plan had been filed. The flight originated from Centennial Airport (KAPA), Englewood, Colorado, at approximately 1515, destined for Pascagoula (KPQL), Mississippi.
The pilot reported that during the preflight inspection, the oil level was acceptable but appeared dirty. The engine would not start due to a low battery; a ground power unit was used. After takeoff, as the aircraft reached about 700 feet AGL, turbine inlet temperature never exceeded 1,550°F, manifold pressure remained at 35 inches, and fuel flow was greater than 32 gallons per hour. Approaching 10,000 feet, the engine began a moderate violent shaking. The pilot noticed oil pressure falling rapidly and oil on the windshield. He declared an emergency and turned back toward KAPA, approximately 26 miles away. The engine then seized. With oil covering the windshield, the pilot side-slipped the airplane and made a forced landing in a hay field. During the landing roll, the nose gear struck a rut and collapsed, and the airplane slid to a stop. The left wing rear spar was subsequently found damaged.
Aircraft Information
N188SR (serial number 4622052), a model PA-46-350P, was manufactured by Piper Aircraft Corporation in 1989. It was powered by a Lycoming TIO-540-AE2A engine (serial number L-9008-61A), rated at 350 horsepower, driving a composite 4-blade MT propeller. Maintenance records showed the most recent airframe annual inspection was performed on August 8, 2012, at a tachometer time of 1,931.6 hours. The previous annual inspection was on May 22, 2011, at a Hobbs meter time of 1,929.89 hours. A gap in maintenance records existed from December 14, 2006, to May 22, 2011.
Wreckage and Impact Information
According to the pilot and confirmed by FAA inspectors, the airplane touched down in an open field and struck two pivotal sprinkler tire trenches, each 18 inches wide and 12 to 18 inches deep. The ground roll measured 800 feet. Oil covered the windshield, engine cowling, and bottom fuselage skin.
Engine Examination
The engine was disassembled and examined at Beegles Aircraft Service, Greeley, Colorado. The front crankshaft seal, immediately behind the propeller flange, had blown out, allowing oil to escape. The oil pump was seized due to oil starvation. The No. 6 cylinder piston connecting rod cap was broken, the No. 5 cylinder piston had a hole and was eroded consistent with detonation, and rust was noted in cylinder domes and along piston edges. The No. 3 connecting rod cap was missing. Metal filings were present throughout the case. The No. 6 crankshaft journal showed heat distress and scoring, and the camshaft had worn lobes (No. 1 exhaust valve lobe worn 0.25 inch).
The fuel pump, which had been leaking and was replaced during the last annual inspection, was bench tested and performed to manufacturer's specifications.
Mechanic's Comments
The mechanic who performed the last annual and 100-hour inspections opined that the engine teardown photographs indicated the engine was running lean, causing exhaust gases to be pushed into the crankcase, leading to oil burning, heating of the No. 5 connecting rod, increased internal pressure blowing out the crankcase seal, oil evacuation, and engine stoppage. The mechanic stated the airplane was kept in a heated hangar and was not exposed to moisture. Two test flights and two ground runs after the oil change were reported as good with no leaks. The mechanic was unaware of any oil pressure problems and saw no reason to borescope the cylinders, noting all cylinders had good compression.