South Portland, ME, USA
N52MY
S.C. Aerostar S.A. Yak52
The pilot had not flown any airplane in almost 2 years. The purpose of the flight was for the pilot to obtain a biennial flight review from an instructor. Additionally, the accident flight was the first flight after the airplane's most recent annual condition inspection, which was completed about 2 weeks before the accident. The airplane made two touch-and-go landings uneventfully. The third landing was full-stop, followed by the pilot back-taxiing to the run-up area and testing the engine. Following the engine run-up, the pilot intended to take off again; he told the air traffic controller that he wanted to fly over the airport at 3,000 feet to do a system check. A witness stated that, during the takeoff, the wings started to rock back and forth. The pilot indicated to the air traffic controller that he wanted to return to the airport, and he began a slow left turn. About one-fourth of the way through the turn, the airplane stalled and descended nose-low into the ground. Examination of the wreckage revealed that one wooden propeller blade had separated at the hub and the other blade had separated about mid-span. The propeller blade and engine damage were consistent with little or no rotation at impact. Adequate fuel was found in the fuel system, and no evidence of contamination was noted. On-scene and metallurgical examination of the wreckage and fuel components did not reveal any preimpact mechanical malfunctions. Although this airplane had a history of fuel flow obstruction due to debris in the fuel system caused by torn hoses as a result of the installation of English-size fuel hoses rather than metric, no evidence of tear debris was found in the fuel system of the accident airplane.
HISTORY OF FLIGHT On July 17, 2010, at 1527 eastern daylight time, an experimental S.C. Aerostar S.A. Yakovlev 52, N52MY, operated by a private pilot, collided with the ground following an in-flight loss of control after takeoff from runway 29 at Portland International Jetport (PWM), Portland, Maine. The personal flight was operated under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the planned local flight. The private pilot and certificated flight instructor (CFI) were fatally injured and the airplane sustained substantial damage. According to witnesses who observed the airplane take off, they saw the wings rocking back and forth as it started to climb. The airplane continued to climb and then started to turn left, back to the airport. All of the witnesses who observed the accident stated that the airplane banked left and then nosed straight down. Those that did not see the actual impact stated that a large cloud of dust and dirt could be seen in the air. Review of surveillance video also confirmed that the airplane descended uncontrolled into terrain. According to the air traffic controller at PWM, who was handling N52MY, the airplane had made two successful touch-and-go landings. The third landing was full-stop and the pilot back-taxied to the run-up area. The controller stated that he believed the pilot was doing an engine run-up. Following the run-up, the pilot requested to take off again, but told the controller that he needed to do a systems check, and that he wanted to stay over the airport and climb to 3,000 feet. The controller approved his request. The controller added that during the takeoff, the wings started to rock back and forth. The controller asked the pilot if he needed to return to the airport. The pilot indicated yes and began a slow left turn. The controller then asked the pilot if there were any problems, and the pilot replied "no, but it’s getting awfully hot in here." The controller then observed the airplane nose down into the ground. PERSONNEL INFORMATION The pilot, age 42, held a private pilot certificate with a rating for airplane single-engine land, which was issued on November 24, 1987, and a Federal Aviation Administration (FAA) second-class airman medical certificate issued on April 9, 2010, with a restriction that he must wear corrective lenses. A review of the pilot’s logbook indicated that his last flight occurred on September 5, 2008. The last flight recorded was for 1.9 hours in the accident airplane. The pilot’s total flight experience recorded was 416.8 hours; of which, approximately 105 hours were in the accident airplane. The pilot’s last flight review was completed on June 23, 2008, and was due to be completed again by June 30, 2010. The CFI, age 66, held an airline transport pilot (ATP) certificate with ratings for airplane single-engine land, airplane multiengine land, rotorcraft helicopter, instrument airplane and rotorcraft. He also held a commercial pilot certificate, with a rating for glider and he held a flight instructor certificate, with ratings for airplane single-engine, airplane multiengine, rotorcraft helicopter, instrument airplane and rotorcraft. His most recent second-class medical certificate was issued on September 1, 2000, with a restriction that he must wear corrective lenses. AIRCRAFT INFORMATION The two-seat, low-wing, retractable gear, single engine airplane, serial number 856211, was manufactured in Romania in 1985. It was powered by a nine cylinder Vendeneyev M14P, 360-horsepower engine. The airplane was issued an FAA experimental exhibition airworthiness certificate on September 12, 2001. A review of the airplane’s most recent annual condition inspection found that the inspection had been performed on July 2, 2010, at an airframe total time of 1,038.2 hours and a Hobbs time of 105.3. At that time, the engine had accumulated 139.3 hours since major overhaul. The airplane's Hobbs Meter indicated 106.1 hours at the time of the accident. According to FAA records, the pilot purchased the airplane on June 21, 2001, at a Hobbs time of 0.00 hours. The airplane was equipped with a V530TA-D35 two-bladed wooden propeller, which had been overhauled and re-installed on December 5, 2009, at a Hobbs time of 101.7 hours. METEOROLOGICAL INFORMATION A review of recorded weather data from the PWM, automated weather observation station, elevation 76 feet, revealed at 1451 conditions were winds 250 degrees at 11 knots gusting to 17 knots, visibility 10 statute miles, scattered clouds at 6,000 feet, temperature 32 degrees Celsius, dew-point 18 degrees Celsius, altimeter 29.73 inches of mercury. WRECKAGE AND IMPACT INFORMATION Examination of the accident site revealed the airplane impacted the ground at a manhole cover on the south side of Maine Mall Road and then traveled about 70 feet on a 011-degree heading to the north side of the street. The airplane came to rest upright, on a heading of 200 degrees, about 1/4 mile southwest of the runway 11 threshold. The airplane's fuel sump was compromised and allowed the remaining fuel on board to drain onto the roadway. The fuel spillage was estimated by local firefighters to have been about 20 gallons. A small postcrash fire in the engine compartment was extinguished by an employee of a local business. The wreckage was recovered from the scene to a hangar. Examination of the airframe found 6 feet of the outboard right wing separated and the wing spar partially separated at its attaching point to the fuselage. The right wing forward attach bolt was sheared and separated from the spar. The empennage aft of the rear cockpit seat was displaced towards the left wing. Control continuity was established to all flight controls. Additionally, the landing gear and flaps were in their retracted positions. The engine and firewall were displaced to the left as a result of impact forces. The engine remained partially attached to the airframe by cables, fuel lines and wiring. The pilot’s canopy was in the full open position after impact; the rear canopy was partially open and in the first lock position. The flap and landing gear handles were in the neutral position and the throttle was observed in the idle position. Examination of the circuit breakers found seven of the eight breakers in the "off" position. The eighth breaker, which powered the landing gear, fuel quantity, oil pressure and other aircraft indicators was in the "on" position. Examination of the engine revealed that one wooden propeller blade had separated at the hub, and the other blade had separated about mid-span, consistent low rotational energy. The Nos. 6, 7, and 8 cylinders sustained impact damage. All other cylinders remained intact. Examination of the engine oil screen found it clear of debris. Both magnetos were removed and produced spark at all leads when rotated by hand. The generator was observed impact-damaged, but rotated freely. The engine driven oil pump was removed and rotated freely by hand. A small amount of oil was observed on the scavenger side of the pump. Cylinder Nos. 6, 7, and 8 were removed from the engine case due to impact damage. The engine accessory section was removed from engine case; all bolts had been stripped out of the supercharger case. Examination of the accessory case found the supercharger main drive gear bound, preventing engine rotation by hand. Additionally, the supercharger case was fractured in three separate locations. Following the removal of the supercharger drive gear, the engine rotated freely by hand. A thumb compression check was performed on all cylinders; cylinder Nos. 1, 4, 6, and 9 had no compression. All cylinders were removed and the exhaust and intake valves were examined. Foreign material was observed under the exhaust valves preventing them from closing completely. The sparkplugs were removed from all cylinders and no anomalies were noted. The engine driven fuel pump, serial number 47510410, was removed and rotated via an electric drill. The pump operated momentarily; however, it would not pump water during subsequent tests. It was noted that the electric drill used during the test could not duplicated the 3,000 rpm developed by the airplane's engine. External air pressure was used to check the pump by-pass valve. The by-pass allowed air to pass through the valve without resistance. Disassembly of the fuel pump found what appeared to be some corrosion internally to the by-pass valve, and the fuel inlet line. The fuel lines had been replaced during the recent inspection. It was noted that the new hoses consisted of U.S. hose materials fitted to the original Romanian or U.S. metallic hose ends. The fuel pump, six fuel lines/hoses, two fuel filters, and a fuel transducer were forwarded to the NTSB Materials Laboratory, Washington, DC. One end of a fuel line was attached to the inlet port of the pump assembly and the other end of the fuel line was placed into a bucket that was filled with water. The bucket was placed at a level that was below the fuel pump. With the aid of a portable electric drill, the drive pin was rotated; however, the procedure did not cause water to exit the outlet portion of the pump. The fuel line was subsequently raised above the pump assembly and filled with water until water started to drip from the outlet portion of the pump (indicating that the pump was primed with water). The fuel line was returned to a level that was below the pump assembly and inserted back into the bucket of water. Rotating the drive rod counterclockwise with the electric drill caused water to flow from the bucket, through the pump assembly, and out of the exit port. The electric drill was operated for about 30 seconds and during the test the pump assembly did not seize. Increasing the speed of the drill caused a greater amount of water to flow out of the exit port. The examination did not reveal any preimpact failures with the pump. Metallurgical examination also revealed that both fuel filter assemblies were absent of contamination. Examination of the six fuel lines revealed that the metal fitting at each end of one of the lines was fractured. Bench binocular microscope examination of the fractured end fittings revealed fracture features at a slant angle relative to the length of the fitting, consistent with overstress separation and with no evidence of a preexisting crack. The inner surface of four of the lines was inspected with a video borescope that contained a 6-millimeter diameter probe. The borescope inspection revealed the inner faces of these four fuel lines contained no evidence of blockage and debris. The inside diameter of the other two fuel lines was smaller than the diameter of the probe and these two fuel lines were not inspected with the borescope. Rather, a copper wire was inserted into one end of the fuel line and removed from the other end of the fuel line. In each case, a cotton ball was tied to the end of the copper wire. The copper wire passed through the two smaller fuel lines without resistance and the cotton ball at the end of the copper wire did not collect debris. Additionally, examination of the fuel flow transducer assembly revealed no evidence of preexisting cracking. For more information, see Material Laboratory Factual Report in the public docket. MEDICAL AND PATHOLOGICAL INFORMATION Autopsies were performed on the pilots on July 19 and 20, 2010, by the Maine Office of Chief Medical Examiner, Augusta, Maine. Toxicological testing was performed on the pilots by the FAA Bioaeronautical Science Research Laboratory, Oklahoma City, Oklahoma. ADDITIONAL INFORMATION A handheld global positioning system receiver was recovered from the wreckage and forwarded to the NTSB Vehicle Recorders Laboratory, Washington, DC. Examination of the unit revealed that no non-volatile memory was stored. According to the owner of the company that originally sold the airplane to the pilot, he was aware of a past problem where the fuel hoses on the Romanian made airplane were metric sizes. When U.S. fuel hoses were used, it was not a perfect fit and possible tears occurred to a portion of the hose, partially obstructing fuel flow; however, no evidence of tear debris was found in the fuel system during the wreckage examination.
The pilot did not maintain adequate airspeed during an emergency return to the airport following a total loss of engine power, which resulted in an inadvertent stall. Contributing to the accident was a total loss of engine power for undetermined reasons and the pilot's lack of recent flying experience.
Source: NTSB Aviation Accident Database
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