Lincoln, AL, USA
N192AB
BURR ANDREW E XIV ROTORWAY EXEC 162F
The experimental helicopter was equipped with a modified kit engine. After completing 1.7 hours of instruction, the instructor and pilot landed uneventfully and fueled the helicopter. Shortly after departure for a nearby airport, about 600 feet above ground level, the helicopter experienced a total loss of engine power. The instructor took control of the helicopter and performed an autorotation to a field; however, the helicopter rolled during touchdown and sustained substantial damage. The experimental engine used the engine case and crankshaft of the kit engine, but an additional 40 horsepower was achieved with the use of modified cylinders, valves, and two digital engine control units (DECUs). If the DECUs sensed a fuel flow disruption, they would reduce engine power to idle. Examination of the wreckage revealed that there was adequate fuel on board. The fuel and fuel filter were absent of contamination. The engine was started and ran continuously for approximately 10 minutes. According to the pilot, who was also the owner of the helicopter, the fuel line was routed next to a hot water line, and a radiator hose was used to separate the two lines. During the accident flight, just prior to the loss of engine power, the pilot noted that the engine was hot, the water temperature was 210 degrees Fahrenheit (F), and the oil temperature was 165 degrees F. The pilot added that the water temperature should only usually be about 10 degrees F hotter than the oil temperature. He believed that heat from the water line caused a vapor lock in the fuel line. Subsequently, when the DECUs sensed a disruption of fuel flow, they reduced engine power to idle; however, that theory could not be verified during a postaccident wreckage examination or an engine test run. The ambient temperature at the time of the accident was 81 degrees F.
On March 19, 2011, about 1750 central daylight time, an experimental, amateur-built, Burr Rotorway Exec 162F helicopter, N192AB, owned and operated by a private individual, was substantially damaged during a forced landing, following a total loss of engine power during cruise flight near Lincoln, Alabama. The instructional flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the planned flight to Talladega Municipal Airport (ASN), Talladega, Alabama. The flight originated from Saint Clair County Airport (PLR), Pell City, Alabama, about 1745. The pilot reported that he had recently purchased the helicopter. He and his instructor had completed about 1.7 hours of dual instruction and landed uneventfully at PLR. They then decided to conduct a short flight to ASN. Shortly after departure, about 600 feet above ground level, the helicopter experienced a total loss of engine power. The instructor took control of the helicopter and performed a 180-degree autorotation to a field. The helicopter touched down in the field about 15 knots; however, the skids were not perfectly straight and subsequently collapsed during the skid. The helicopter rolled over and the main rotor blades struck the ground, resulting in substantial damage to the helicopter. The pilot added that the helicopter held 16 gallons of fuel and they departed with approximately 6 gallons of fuel for the short flight. Some fuel spilled after the accident, but they were able to recover an additional 3.5 gallons of fuel from the wreckage and no contamination was noted in the fuel or fuel filter. Additionally, under the supervision of a Federal Aviation Administration inspector, the instructor started the engine on the wreckage and ran it for approximately 10 minutes with no anomalies noted. The inspector also confirmed adequate fuel on board and no evidence of contamination. The pilot further stated that although Rotorway offered a 150-horsepower engine for the helicopter kit, his completed helicopter was equipped with an experimental Vertical Performance Systems (VPS) 190-horsepower, four cylinder, fuel injected engine. The engine was equipped with two digital engine control units (DECUs). The DECUs were forwarded to the NTSB Vehicle Recorder Laboratory, Washington, DC, for data download; however, no data was recovered from the units. According to the owner of VPS, he used Rotorway's engine case and crankshaft, but achieved an additional 40 horsepower with the use of modified cylinders, valves, and DECUs. The owner further stated that he believed the engine did not lose all power during the accident sequence. It was possible that a disruption in fuel flow caused the DECUs to reduce power to 1,500 rpm. When adequate fuel flow was restored, the DECUs increased engine power/rpm. According to the pilot, the fuel line was routed next to a hot water line and a radiator hose was used to separate the two lines. During the accident flight, a few minutes prior to the loss of engine power, the pilot remarked to the instructor that he could "really feel the heat off the engine." At that time, the water temperature cockpit indication was 210 degrees Fahrenheit (F) and the oil temperature cockpit indication 165 degrees F. The pilot added that the water temperature should usually only be about 10 degrees F hotter than the oil temperature. He believed that heat from the water line caused a vapor lock in the fuel line. Subsequently, when the DECUs sensed a disruption of fuel flow, they reduced engine power to idle. According to maintenance records, the helicopter's most recent condition inspection was completed on October 9, 2010. At that time, the helicopter had accumulated 152.5 total hours of operation. The 1753 recorded weather, at an airport located about 15 miles east of the accident site, included calm wind, clear sky and temperature 81 degrees F.
A total loss of engine power during cruise flight for undetermined reasons.
Source: NTSB Aviation Accident Database
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