Truckee, CA, USA
N5909L
AMERICAN AA-1
The private pilot was conducting a ferry flight for the airplane's owner. The pilot reported that, before takeoff, he leaned the fuel mixture for taxi but that, on takeoff, the mixture was full rich. During the initial climb, the engine lost power; the pilot stated that he did not remember anything after the loss of power occurred. The airplane subsequently collided with trees about 8 miles east of the airport, which is at an elevation of 5,901 ft and surrounded by mountainous terrain. Postaccident examination of the airframe and engine revealed no mechanical anomalies that would have precluded normal operation. According to the airplane owner's manual, during takeoff or climb from high-altitude airports, the engine should be leaned to achieve maximum rpm; the calculated density altitude at the time of the accident was about 6,552 ft. The manual further stated that, at full throttle climb at altitudes above 5,000 ft, the fuel mixture should be leaned for smooth engine operation. The manual noted that a rough-running engine can result from an improper fuel/air mixture.
HISTORY OF FLIGHTOn May 23, 2013, about 1210 Pacific daylight time, an American Grumman AA-1, N5909L, lost engine power during the takeoff initial climb out from the Truckee-Tahoe Airport (TRK), Truckee, California, and impacted trees near the Glenshire subdivision in Truckee, about 8 miles east of the airport. The airplane was owned by a private individual and piloted by the commercial pilot who was ferrying the airplane to New York for the new owner. The airplane sustained substantial damage. The pilot, the sole occupant, was ejected from the airplane, and sustained serious injuries. Visual meteorological conditions prevailed for the flight, and no flight plan had been filed. The flight was destined for Derby Field (LOL), Lovelock, Nevada. The pilot was interviewed by a Federal Aviation Administration (FAA) inspector. The pilot stated that he leaned the airplane engine on the ground utilizing the cylinder head temperature (CHT) gauge. After leaning the airplane with the fuel pump on, he commenced with the takeoff. The pilot stated that during the climb, the engine quit, and he thought the airplane was going to stall. The pilot stated that he does not remember anything after the loss of engine power, until he woke up, and crawled to the cockpit to look for his cell phone to alert the authorities of the accident. The pilot called 911 about 1500, requesting assistance. A responding deputy from the Nevada County Sheriff's department stated that the debris field was about 100 yards in length with the tops of several small trees showing visible signs of impact damage. Both wings separated from the airplane, and were found about 50 feet from the main wreckage. The smell of fuel was present. The deputy reported that the canopy had shattered leaving the cockpit open. In the pilot's written statement, he reported that the airplane was refueled at TRK. He stated that he leaned the airplane for taxi, and on takeoff the mixture was full rich. During climb out the engine quit; the airplane slowed, and wanted to stall. The pilot stated that he did not remember anything else as he had lost consciousness. The fuel receipt indicated that the pilot had refueled the airplane at 11:30, the morning of the accident, with 10.320 gallons of 100 low lead fuel. PERSONNEL INFORMATIONThe pilot reported his total time as 1,027.5 total hours with 10 hours in the accident make and model. According to the pilot's logbook, his last flight review was performed on June 6, 2009. The pilot submitted in his NTSB pilot/operator report form 6120.1, that his last flight review was performed on October 30, 2011, in a Cessna 152. Subsequently, the pilot submitted a written statement and logbook entry that verified his last flight review was in October 2011. AIRCRAFT INFORMATIONThe Grumman American AA-1A, serial number AA1-0209, N5909L, was manufactured in 1969, and was certified under the normal/utility category. It was equipped with a Lycoming O-235-C2C engine. According to the airframe logbook, the last entry dated July 17, 2012, a 100-hr inspection was performed at a tachometer time of 400.06 hours and a total airframe time of 3,891.42 hours. There were no additional entries in the airplane logbook. According to the engine logbook, the last entry dated July 17, 2012, an annual/100-hr inspection was performed at a tachometer time of 400.06 hours, a total time of 3,388.62 hours, and time since major overhaul of 1,946.62 hours. There were no additional entries in the engine logbook. According to the airplane's Owner's Manual, section III Operating Procedures, there was a note that stated in part, that during takeoff or climb from high-altitude airports, the engine should be leaned to achieve best power (maximum rpm). Section V Performance Charts, note, item 1 stated that at a full throttle climb, mixture leaned above 5,000 feet to smooth engine operation. Section VII Care of Airplane indicated that if a rough-running engine was encountered, it may be for any one of the following reasons, of which, one reason was an incorrect fuel/air mixture. METEOROLOGICAL INFORMATIONWeather obtained from the airport indicated that at 1145, wind was from 260 degrees at 7 knots with gust to 14 knots; visibility was 10 statute miles, a broken cloud layer at 7,000 feet, temperature 9 degrees C, dew point -11 degrees C, and altimeter setting 29.97 inches of mercury. Utilizing the temperature, dew point, and altimeter setting, the density altitude at the takeoff location would have been about 6,552 feet. AIRPORT INFORMATIONThe Grumman American AA-1A, serial number AA1-0209, N5909L, was manufactured in 1969, and was certified under the normal/utility category. It was equipped with a Lycoming O-235-C2C engine. According to the airframe logbook, the last entry dated July 17, 2012, a 100-hr inspection was performed at a tachometer time of 400.06 hours and a total airframe time of 3,891.42 hours. There were no additional entries in the airplane logbook. According to the engine logbook, the last entry dated July 17, 2012, an annual/100-hr inspection was performed at a tachometer time of 400.06 hours, a total time of 3,388.62 hours, and time since major overhaul of 1,946.62 hours. There were no additional entries in the engine logbook. According to the airplane's Owner's Manual, section III Operating Procedures, there was a note that stated in part, that during takeoff or climb from high-altitude airports, the engine should be leaned to achieve best power (maximum rpm). Section V Performance Charts, note, item 1 stated that at a full throttle climb, mixture leaned above 5,000 feet to smooth engine operation. Section VII Care of Airplane indicated that if a rough-running engine was encountered, it may be for any one of the following reasons, of which, one reason was an incorrect fuel/air mixture. TESTS AND RESEARCHThe airplane and engine were examined on July 16, 2013. A visual examination of the engine revealed no obvious pre impact damage. All of the accessories remained secured in their proper location at the rear of the engine. The top spark plugs, the starter, and the lower cowling were removed to facilitate manual rotation of the propeller to check for engine continuity. No binding was noted when the propeller was rotated, and thumb compression was obtained in all cylinders in the proper firing order. There is a detailed report attached to the public docket for this accident. The examination revealed no mechanical anomalies that would have precluded normal operation.
The pilot's failure to lean the fuel mixture during takeoff in high-density altitude conditions, which resulted in a loss of engine power.
Source: NTSB Aviation Accident Database
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