Brigham City, UT, USA
N58AS
NORTHWING APACHE SPORT
A witness located near the accident site reported observing the weight-shift-control trike flying around the area at a low altitude before hearing the engine power increase and seeing the trike ascend to avoid striking trees. The witness observed the trike continue to maneuver around the area and conduct a series of turns before he lost sight of the trike. Another witness reported seeing the trike approach two sets of power lines and then suddenly bank sharply left and descend into the ground. Postaccident examination of the recovered trike revealed no evidence of any preexisting mechanical anomalies that would have precluded normal operation.
On April 8, 2014, about 1720 mountain daylight time, an experimental Northwing Apache Sport, N58AS, was substantially damaged when it impacted the ground while maneuvering near Brigham City, Utah. The weight shift control trike 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 trike, was fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from the local area at an unknown time. A witness located near the accident site reported observing the accident weight shift control trike flying in a northerly direction at a low altitude. The witness stated that the trike turned to the east sharply, as if the pilot was looking for a place to land, however, it appeared that the pilot added power to avoid striking trees, and turned to the south. The witness further stated that the trike turned to the north, and thought that the pilot was going to land on the road south of the marina. Witnesses driving north and south on Interstate 15 stated that the trike was traveling in an easterly direction when it approached two sets of high tension power lines, and suddenly banked steeply to the left. Subsequently, the trike descended into terrain. Examination of the trike by local law enforcement revealed that it came to rest on its left side on a road adjacent to two sets of high tension power lines, situated on both the east and west sides of the road. All major structural components were present at the accident site. The trike was recovered to a secure location for further examination. Examination of the trike on April 10 by investigators from the National Transportation Safety Board (NTSB) revealed that the forward point where the two wings joined was crushed aft and dirty; the left wing leading edge had dirty span-wise scuff marks. Multiple structural and control tubes buckled, fractured, and separated; all observed fracture surfaces were angular and jagged. All observed cable separations were splayed. The three-blade propeller had one blade fractured about one-third of the span from the hub with the blade bent aft 90 degrees under the engine. The fracture was jagged and angular. The blade exhibited chordwise striations, and the paint on the cambered side was scuffed. The second blade split mid chord with the back side of the blade peeled away all the way down to the root. The third blade was split mid chord, but the halves remained in position. The outboard half of the blade exhibited chordwise striations on the cambered side, and all paint was rubbed off of the aft part of the blade in this area. The Rotax 582 engine, serial number 6141213, remained intact. Movement of the throttle control followed movement of the throttle lever in the cockpit. The crankshaft was rotated by hand using the propeller through 360 degrees, with observed rotation in the gearbox. The fuel filter was clean. The fuel tank appeared over half full, and the fluid was clear and free of debris. The bottom covers of both carburetors were removed. Both screens were clean, and both bowls were clean and contained fluid. The fluid in both bowls was tested with a water detecting paste, and there was none detected. The black composite floats were undamaged. Both float arms moved freely. The upper chambers of the carburetor were unremarkable. Review of photos taken by a Federal Aviation Administration (FAA) inspector on April 9, 2014, revealed that the carburetor vent lines were in place and exhibited slits as required per the Rotax 582 Installation Manual. The Utah State Medical Examiner conducted an autopsy on the pilot on April 9, 2014. 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, volatiles, and drugs were tested, and had negative results. Review of the pilot's logbook revealed that the pilot was issued a private pilot certificate with an airplane single-engine land rating on January 25, 1986. Logbook entries for various flights continued until September, 1989, totaling 152.1 hours of flight time, of which 126.9 hours were pilot in command. The pilot had logged three introductory flights in a Gyrocopter in 2009, totaling 2.5 hours of flight time. Further review of the pilot's logbook revealed an introductory flight on September 8, 2012, in a weight shift control trike, totaling 1 hour, and between December 10, 2013 and February 22, 2014, the pilot had logged 18 flights in weight shift control trikes with an instructor, totaling 16 hours. From March 8, 2014, to the most recent logbook entry dated April 4, 2014, the pilot had logged 4 flights, totaling 3.3 hours of flight time in the accident trike.
The pilot’s failure to maintain aircraft control while maneuvering near power lines.
Source: NTSB Aviation Accident Database
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