Lock Haven, PA, USA
N16667
TAYLOR J-2
The pilot reported that, after departure and while in the traffic pattern, the airplane was operating normally but that the engine then suddenly lost partial power. Due to the airplane's low altitude at the time of the power loss, the pilot decided to land between several houses in a clearing. During the forced landing, the airplane impacted trees. Examination of the engine revealed that the exhaust valve on the No. 1 cylinder remained in the "open" position and would not move when the engine was rotated by hand. Further examination revealed that the exhaust valve was stuck in the valve guide. Although automotive fuel was approved for use in this engine, 100LL aviation fuel was used for the accident flight. According to manufacturer guidance, continued operation with automotive fuel can lead to sticking. However, it could not be determined if automotive fuel had been used during previous flights and resulted in the valve sticking or if the use of the 100LL fuel resulted in the valve sticking. An entry in the engine maintenance records revealed that the valve guides and stems were to be lubricated every 5 hours and cleaned every 10 hours; however, no entry was found in the records indicating that the valve guides and stems had been lubricated since the airplane's most recent inspection about 15 flight hours before the accident. Due to the exhaust valve being stuck, the exhaust valve head separated from its stem during the initial climb, which subsequently resulted in the failure of the exhaust valve's associated cylinder components and the partial loss of engine power.
HISTORY OF FLIGHT On June 20, 2014, about 1625 eastern daylight time, a Taylor J-2, N16667, impacted a tree during a forced landing in a residential area after a partial loss of engine power near William T. Piper Memorial Airport (LHV), Lock Haven, Pennsylvania. The airplane was owned and operated by an individual. The commercial pilot was not injured and the airplane sustained substantial damage to both wings. Visual meteorological conditions prevailed and no flight plan had been filed for the local flight, which was operated under the provisions of Title 14 Code of Federal Regulations Part 91. According to the pilot, the flight had just departed and was in the traffic pattern. The airplane was "operating smoothly" and it was his first time flying behind a single-bladed propeller, when the engine suddenly lost partial power and the airplane was unable to maintain altitude. Unable to return to the airport or make a landing in a nearby river due to the low altitude of the airplane, he decided to attempt a landing in a clearing between several houses. During the forced landing, the airplane impacted a tree and came to rest in an approximate 45 degree nose down attitude in the tree. According to an eyewitness report, the airplane taxied to, and departed from a turf runway. The airplane became airborne about 1,000 feet down the runway. About 100 feet above ground level the airplane banked to the right and subsequently began a gradual descent. During the descent a "faint smoke trail" was observed "trailing behind the airplane." PERSONNEL INFORAMTION According to the pilot and Federal Aviation Administration (FAA) records, the pilot, age 66 held a commercial pilot certificate with ratings for airplane single-engine land, multiengine land, instrument airplane, and a flight instructor certificate with a rating for airplane single-engine land. He also held a second-class medical certificate which was issued on May 5, 2011. He reported 8,000 total flight hours of flight experience and 40 of those hours in the accident aircraft make and model. AIRCRAFT INFORMATION According to FAA records the airplane was manufactured in 1936. It was powered by a 37-hp Continental A-40-3 engine, serial number 756, driving a EVEREL 1-blade propeller, which was installed on the day of the accident. The airplane's most recent annual inspection, was accomplished on August 15, 2013. At the time of that inspection the airplane and engine had 244.1 total hours of time in service. A hand written entry dated the day of the accident indicated "260:15" total hours of time in service. Records indicated that on August 30, 2009, a supplemental type certificate authorized the use of Auto Fuel or 82 UL Avgas in the airplane. According to an entry in the engine maintenance records, the valve guides and stems were to be lubricated every 5 hours and cleaned every 10 hours; however, no entry of such lubrication could be located within the maintenance records since the last inspection. METEOROLOGICAL INFORMATION The 1554 recorded weather observation at Williamsport Regional Airport (IPT), Williamsport Pennsylvania, located about 24 miles to the east of the accident location, included wind from 280 degrees at 6 knots, 10 miles visibility, clear skies, temperature 27 degrees C, dew point 8 degrees C; altimeter setting 29.97 inches of mercury. AIRPORT INFORMATION The airport was a publically owned airport and at the time of the accident did not have a control tower. There were two runways designated runway 9L/27R, and runway 9R/27L. The runways were reported as "in good condition" at the time of the accident. Runway 9L/27R was a 3799-foot-long by 75-foot-wide asphalt runway. Runway 9R/27L was a 2179-foot-long by 100-foot-wide turf runway. According to the pilot and an eyewitness runway 9R was used. The airport elevation was 556 feet above mean sea level. WRECKAGE AND IMPACT INFORMATION Examination of the airplane by an inspector from the Federal Aviation Administration (FAA) revealed that both wings and the right wing strut were substantially damaged. At least 4 gallons of blue fluid, similar in color and smell as 100LL aviation fuel, were removed from the fuel tank following the accident; it was free of debris and water. A blue fluid, similar in color and smell as 100LL aviation fuel was found in the carburetor and was free of debris. The engine was rotated by hand and rotated without restriction. Thumb compression was verified on cylinder Nos. 2, 3, and 4; however, no compression was noted on cylinder No. 1. All of the spark plugs were removed, were "normal" in color, and exhibited no fouling. On July 1, 2014 the engine was disassembled with oversight provided from an FAA inspector. During the examination, the cylinder No. 1 exhaust valve was noted as in the "open" position, and manual rotation of the engine revealed no valve train motion on the No. 1 cylinder exhaust valve. Further examination revealed that the exhaust valve was "stuck" in the valve guide. Photographic examination revealed that the exhaust valve pushrod was separated from the exhaust valve. ADDITIONAL INFORMATION Teledyne Continental Motors Service Bulletin (SB) M77-3 addressed the various grades of fuel approved for aircraft engines, and the potential for sticking valves when utilizing 100LL aviation fuel in older series engines. The SB stated that 100LL was an acceptable alternative fuel and continued on to indicate that the amount of tetraethyl lead in these higher grade fuels had increased the lead build up and fouling of spark plugs along with valve erosion incidents reported on some lower compression engines. When using this fuel, exhaust valve sticking could result from lead salt accumulation in the lubricating oil. Under such circumstances, an exhaust leak between the exhaust elbow flange and the exhaust port face was possible, which resulted in localized cylinder head overheating and subsequent exhaust valve and guide distress. The SB further stated this condition could be reduced with regular oil changes, and by the replacement of the valves and guides with units which were more tolerant of lead contamination. The SB further stated that automotive fuels can contain additives that act as corrosive agents, formulate gum deposits and therefore, increase combustion chamber deposits. Continued operation on automotive fuel could lead to detonation, pre-ignition and sticking or eroded valves. An FAA chart, titled "Conditions Favoring Carb Ice Formation," indicated that with the ambient temperature and dew point, "serious icing at glide power" was probable at the time of the accident.
The airplane owner’s failure to clean and lubricate the engine valve guides and stems, which resulted in a partial loss of engine power during the initial climb due to an exhaust valve failure.
Source: NTSB Aviation Accident Database
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