Hunting Island, SC, USA
N721FP
FPNA LLC A-22 Valor
While maneuvering as part of a formation flight, the pilot noticed that the electronic instruments were dimming and that the oil pressure gauge indicated zero. About 10 seconds later, the engine seized and the pilot performed a forced landing on a dirt road. The airplane incurred substantial damage during landing when it veered into a ditch. A postaccident examination of the engine revealed that the No.1 cylinder's connecting rod was protruding through the top of the engine case. Upon removal of the engine cowling, the brass B-nut was found separated from the oil cooler fitting. There was no apparent damage to the threads on the inside of the nut and no damage on the outside of the fitting. Oil was present in the oil sump and on the oil dipstick. The engine had a dry sump forced lubrication system. The oil pump extracts the oil from the oil tank via the oil cooler and forces it through the oil filter to the engine. According to notations found in the airplane's maintenance logbook, the engine's oil had been changed 1.6 flight hours prior to the accident. According to the owner, maintenance personnel did not touch the oil cooler or fittings during the oil change service. The engine manufacturer’s Service Instructions manual had a warning associated with servicing and purging of the oil system. The warning stated that maintenance personnel should carefully check all lubrication system connections, lines and clamps for leaks and security.
On December 23, 2009, about 1532 eastern standard time, a FPNA A-22 Valor, Special Light Sport Airplane (S-LSA), N721FP, was substantially damaged during a forced landing following a loss of engine power near Hunting Island, South Carolina, approximately 14 miles east of the Savannah/Hilton Head International Airport (SAV), Savannah, Georgia. The certificated commercial pilot and one passenger were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local formation flight which was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. The pilot reported that he and his passenger were in a formation flight that departed SAV approximately 15 minutes prior to the accident. They were en route back to the departure airport when the pilot noticed that the electronic instruments were dimming and the oil pressure gauge read zero. About 10 seconds later, the engine seized and he notified Savannah Approach Control of his intended emergency landing location. The airplane's owner who was flying a second airplane in formation witnessed the accident. He observed white smoke coming from the engine area of the airplane and about 20 seconds later, the engine appeared to quit. He watched the airplane descend and land on a dirt road and as the airplane decelerated, it veered to the left into a ditch. The owner reported that on the day of the accident, the airplane had been topped off with aviation gas. Prior to the accident flight the owner had flown the airplane for 1.3 hours and reported that there were no indications of mechanical issues. Examination of the airplane by an FAA inspector revealed that the left wing was bent aft from a point approximately half way out on the wing to the tip at an approximate 45 degree angle, and the left main landing gear was found separated from airframe. The carry through structure that the main landing gear had been attached to was fractured About 21 gallons of usable fuel was drained from the tanks at the accident site.. A connecting rod from the No.1 cylinder was found protruding through the top of the engine case. Upon removal of the engine cowling the brass B-nut was found separated from the oil cooler fitting. Further inspection of the B-nut revealed that there was no apparent damage to the threads on the inside of the nut and no damage on the outside of the fitting. Oil was present in the oil sump and on the oil dipstick. The airplane was equipped with a Rotax 912 UL engine. The engine had a dry sump forced lubrication system. The oil pump extracts the motor oil from the oil tank via the oil cooler and forces it through the oil filter to the points of lubrication in the engine. On November 4, 2009, the airplane underwent a 100-hour inspection and at that time had 463.2 total hours. According to the owner, the airplane had been flown approximately 1.6 hours since its most recent oil change. He further reported that during the oil change they did not touch the oil cooler or fittings. He further stated that "if the engine would break the suction seal it is a big ordeal to re-prime the oil system so we don't touch it." A review of the airplane maintenance logbooks revealed that the day prior to the accident, the oil and oil filter had been drained and replaced. The airplane at that time had 483.1 total hours recorded on the tachometer. The Rotax Service Instructions manual "Purging of Lubrication System For Rotax Engine Type 912 and 914," Section 3 "Accomplishment/Instructions" states in part "WARNING: Carefully check all lubrication system connections, lines and clamps for leaks and security."
Maintenance personnel's inadequate inspection of the oil system's fittings during a routine oil servicing, which resulted in oil starvation due to a loose and/or detached oil line B-nut fitting that led to the engine seizing while in flight.
Source: NTSB Aviation Accident Database
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