Aviation Accident Summaries

Aviation Accident Summary ATL05LA007

Guntersville, AL, USA

Aircraft #1

N19TL

Piper PA-32RT-300T

Analysis

During cruise flight the engine lost power, the pilot declared an emergency and decided to make a forced landing in a nearby field. While maneuvering for the emergency landing the airplane collided with a tree short of the intended landing area, fell to the ground, and burst into flames. Examination of the engine found no measurable quantity of oil remained in the sump, only residual oil remained, which was dark black in color. The crankcase was breached, and large holes in the crankcase were observed above the #2 and #6 cylinders. The internal components of the valve train were examined and widespread spalling of the tappet bodies was noted. Severe wear of the camshaft was also noted. Four of the nine cam lobes exhibited severe wear. The crankshaft main bearings exhibited dirt and particle embedment from metal particles contaminating the oil supply. According to a Service letter issued by Lycoming; Service Letter No. SL206A, dated May 5, 1985 which addresses the subject of field reconditioned tappet bodies, SL206A states that field reconditioned tappet bodies often leads to camshaft and tappet body problems in a very short time, thereby necessitating their removal and replacement. Severe wear or spalling of the cam lobes and tappet bodies can result in metal particles contaminating the oil supply.

Factual Information

On October 21, 2004, at 1503 central daylight time, a Piper PA-32RT-300T, N19TL, registered to BLW LLC, and operated by an individual, as a 14 CFR Part 91 personal flight, collided with trees during a forced landing following a loss of engine power in Guntersville, Alabama. Visual meteorological conditions prevailed and an instrument flight rules flight plan was filed. A post-crash fire ensued and the airplane was destroyed. The instrument rated private pilot reported serious injuries. The flight originated from Gallatin, Tennessee, on October 21, 2004, at 1345. According to the pilot, the engine started running rough and then lost power. He said there was oil on the left side of his wind screen. The pilot contacted Huntsville, Alabama Air Traffic Control (ATC) and declared an emergency and ATC diverted him towards Guntersville, Alabama, the closest airport to his location. Shortly after that, the pilot lost radio communications with ATC, and the pilot became unsure of his location. At that time he observed a field ahead of him and decided to land there. The pilot stated that just prior to landing the airplane collided with trees, fell to the ground and caught fire. The pilot unbuckled his seat belt and crawled out of the airplane as far as he could. Shortly after that the first responders arrive at the accident site, the pilot was transported to the hospital by care flight helicopter. On November 18, 2004, the investigation was reconvened with assistance from representatives of the FAA, The New Piper Aircraft Company, and Lycoming engines. Examination of the airframe found both wings separated from fuselage at the wing roots. The left wing outboard leading edge displayed a circular impact deformation three feet from the tip. The right wing outboard fuel tank had fire damage. The fuel cap was in place and fuel, blue in color, remained in the inboard fuel tank. The empennage was separated about four feet from the tail cone. The stabilator had impact and fire damage and was attached. The top right side of the stabilator displayed black and brown soot. The stabilator stops had fire damage and were in-place. Stabilator continuity was established from the stabilator to the empennage separation area. The stabilator trim mechanism measured 5/8 of an inch. The fuselage and cabin furnishings including the instrument panel were fire damaged. Examination of the engine found fire damage throughout the rear accessory section area. All of the fluid carrying hoses were fire damaged. No measurable quantity of oil remained in the sump, only residual oil remained, which was dark black in color. The crankcase was breached, and large holes in the crankcase were observed above the #2 and #6 cylinders. The aft hole in the crankcase continued into the top of the rear case. The engine was accessed an all sides. All accessory components were removed. The engine cylinders were removed and the power section of the engine was disassembled for examination. The internal components of the valve train were examined and widespread spalling of the tappet bodies was noted. Severe wear of the camshaft was also noted. Four of the nine cam lobes as referenced from front to rear exhibited severe wear. The crankshaft main bearings exhibited dirt and particle embedment from metal particles contaminating the oil supply. The oil filter element was examined and found to contain small ferrous and non-ferrous metal particles. The oil suction screen was examined and found to contain slivers and chips of extruded connecting rod bearing material. The crankshaft was found to contain a large amount of sludge within the hollow oil passage to the propeller. The sludge found within the crankshaft was from oil contamination from metal particles contaminating the oil supply. Connecting rods #1 and #3 remained attached to the crankshaft but exhibited heat distress from oil starvation. The #1 and #3 connecting rod bearings were scored. The #1 and #3 connecting rod bolts remained secured. The connecting rods #2, #4, #5 and #6 were broken, heavily fragmented, and all of the partial remains exhibited heat distress. The associated bearings were destroyed. Rod caps and bolts were fragmented and were not distinguishable as to their original position. Portions of broken connecting rods bolts exhibited necking of the shank. A review of maintenance records revealed that the engine had been field overhauled on April 30, 1993, 1,446.24 flight hours prior to the accident. On March 29, 2000, 743.57 flight hours since overhaul, the engine was disassembled for a propeller strike inspection. The maintenance entry for the prop strike inspection included information concerning the internal valve train as follows: Lifter bodies (12) reground. According to a Service letter issued by Lycoming; Service Letter No. SL206A, dated May 5, 1985 which addresses the subject of field reconditioned tappet bodies, SL206A states that field reconditioned tappet bodies often leads to camshaft and tappet body problems in a very short time, thereby necessitating their removal and replacement. Severe wear or spalling of the cam lobes and tappet bodies can result in metal particles contaminating the oil supply.

Probable Cause and Findings

Total loss of engine power due to engine oil contamination, engine oil starvation, and multiple connecting rod bearing failures.

 

Source: NTSB Aviation Accident Database

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