Paulden, AZ, USA
N6383W
HOWES RV-6
A witness observed the accident airplane performing turns to the left and right and trailing white smoke. The witness stated that the airplane was about "tree-top level" when it pitched down and impacted the ground. Examination by a Federal Aviation Administration inspector revealed oil along the bottom side of the fuselage and on the tailwheel. A friend of the pilot, who was also an aircraft mechanic, reported that prior to the accident flight he and the pilot found an oil leak originating from a stainless steel high-pressure oil line from the propeller governor to the forward area of the engine crankcase. The mechanic stated that he had removed the oil line and the pilot had it repaired by a local weld shop. After reinstallation of the oil line, the mechanic conducted an engine run and did not observe any oil leaks originating from the oil line. The pilot then decided to fly the airplane around the area on a test flight. According to the mechanic, as the airplane departed the runway, he observed a trail of white smoke originating from the airplane. Despite two requests by the mechanic to return to the airport, the pilot stated that "everything was fine" and he was going to continue to a nearby airport. No further radio communication was received from the pilot. Examination of the engine revealed that the stainless steel high pressure oil line from the propeller governor was in place. The oil line exhibited a repair weld on the forward area of the line, and corresponding wear marks were observed on the engine crankcase. The oil line was removed and the forward end of the oil line was capped off using a bolt. The area of the weld was placed under water and compressed air pressure was applied to the opposite end of the oil line. A leak was observed originating from the area of the weld. Partial disassembly of the engine revealed that the number two connecting rod was separated from the crankshaft and exhibited signatures consistent with oil starvation.
HISTORY OF FLIGHT On March 18, 2009, about 1750 mountain standard time, an amateur built Howes RV-6 experimental airplane, N6383W, was substantially damaged when it impacted terrain following a loss of control during a forced landing near Paulden, Arizona. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The private pilot, sole occupant of the airplane, was killed. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight. The cross-country flight originated from Sedona Airport (SEZ), Sedona, Arizona about 20 minutes prior to the time of the accident with an intended destination of Big Springs Ranch Airport (AZ27), Paulden, Arizona. A witness located near the accident reported observing the airplane flying overhead his/her location performing turns to the left and right while trailing white smoke. The witness stated that as the airplane was about "tree-top level," it pitched down and impacted the ground. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed that the airplane came to rest in an upright position within an open dirt field. All primary flight control surfaces and major components of the airplane were located within 10 feet of the main wreckage. The leading edges of the left and right wings were crushed aft to the main wing spar. The forward area of the fuselage was also crushed aft. Oil was observed along the bottom side of the fuselage and on the tailwheel. The wreckage was relocated to a secure facility for further examination. Information provided by a friend of the pilot, who was a certificated Airframe and Powerplant (A&P) mechanic, revealed that about six weeks prior to the accident, the pilot was repositioning the airplane from AZ27 to his home in Texas. During the cross-country flight, the pilot landed at SEZ to refuel the airplane and discovered oil leaking from the engine area. The A&P mechanic reported that on the day of the accident, he met the pilot at SEZ to look at the airplane. After the A&P mechanic cleaned the engine compartment and conducted a pre-flight inspection of the airplane, he conducted an engine run-up for about 20 minutes. After engine shutdown, he then inspected the engine and did not observe any oil leaks. The pilot then started the airplane, taxied to the runway, performed a run-up, and proceeded to takeoff. During the initial climb, the A&P mechanic noticed white smoke trailing from the airplane and advised the pilot via a handheld radio to return to the airport. The pilot executed a 180-degree turn and landed. The A&P mechanic stated that after again cleaning the engine and conducting a test run, he observed oil leaking from behind the alternator. Further inspection revealed that the stainless steel oil line from the propeller governor to the forward part of the crankcase exhibited an abrasion and corresponding wear mark on the crankcase. The A&P mechanic further stated that after a conversation with the pilot, it was decided to weld the abrasion on the oil line as a "diagnostic tool." He added that the pilot took the oil line to a local weld shop and had the abrasion welded. Upon the pilot returning to the airport with the repaired oil line, the A&P mechanic installed the oil line on the engine and conducted an engine run. He noted that after completion of the engine run, no oil leaks were observed and he reinstalled the engine cowling. The A&P further reported that the pilot wanted to fly the airplane and they decided that the pilot would depart the airport and climb to an altitude of about 8,000 to 10,000 feet mean sea level and circle the airport for about 10 – 15 minutes prior to returning to the airport. About 30 minutes later, the pilot performed a runup and proceeded to takeoff. Upon takeoff, the A&P mechanic observed a small amount of white smoke originating from the airplane and informed the pilot of his observation. Despite two requests from the A&P mechanic, the pilot stated that "everything was fine and he was going to AZ27." The A&P mechanic then suggested a few alternate airports for the pilot to land at. The pilot replied "not to worry" and that he was going to continue to AZ27. PERSONNEL INFORMATION The 49 year old pilot held a private pilot certificate with single-engine land, multi-engine land, and instrument airplane ratings. According to FAA records, the pilot was issued a third-class airman medical certificate on March 30, 1999, with no limitations stated. The pilot's logbook was not recovered for examination. The pilot reported on his March 30, 1999, medical certificate application that he had accumulated 2,850 total flight hours. MEDICAL AND PATHOLOGICAL INFORMATION The Yavapai County Coroner conducted an autopsy on the pilot on March 19, 2009. The medical examiner determined that the cause of death was "blunt force injuries.” The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed toxicology tests on the pilot. According to CAMI's report, carbon monoxide, cyanide, volatiles, and drugs were tested, and had negative results. TESTS AND RESEARCH On May 4, 2009, the engine was examined at the facilities of Air Transport, Phoenix, Arizona. The examination of the Lycoming O-360-A1A, serial number L-36294-36A, revealed that the engine was crushed aft into the engine firewall. The engine mounts were intact and impact damaged. The right magneto, vacuum pump, starter, oil filter, carburetor, propeller, and crankshaft propeller flange were displaced from the engine. A hole was observed within the top portion of the crankcase above the number two cylinder along with a portion of connecting rod protruding through the hole. Several cracks were also observed in the crankcase surrounding the number two cylinder. The high pressure propeller governor oil line from the propeller governor to the nose of the crankcase was found in place and intact. A portion of rubber hose material was observed on the forward part of the oil line. The oil line was removed and examined. An area of thermal signatures consistent with a weld repair was observed near the forward section of the line, underneath the rubber hose material. The forward end of the oil line was capped off using a bolt and the area of the weld was placed under water. Compressed air pressure was applied to the opposite end of the oil line. A leak was observed originating from the area of the weld. Examination of the crankcase revealed a wear mark in the same area as the weld on the oil line. The number one cylinder was removed from the crankcase. The number one connecting rod and piston were intact. The number one piston exhibited slight mechanical damage to the piston skirt. The piston head was dark in color. All number one piston rings remained intact and moved freely within their grooves. The number two connecting rod was observed separated from the crankshaft and piston. The number two piston and surrounding area of the crankcase exhibited mechanical damage.
A total loss of engine power due to oil starvation as a result of a leak from the inadequate weld repair of a high-pressure oil line. Also causal was the pilot's failure to maintain adequate airspeed while maneuvering that resulted in a stall during an attempted off-field landing and the pilot's decision to continue flight with a known discrepancy.
Source: NTSB Aviation Accident Database
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