History of Flight
On September 16, 2013, about 1535 Pacific daylight time, a Garlick UH-1B, registration N204UH, experienced a tailboom separation while logging in heavily wooded terrain approximately 3 miles east of Detroit, Oregon. The pilot, the sole occupant, was fatally injured. The helicopter sustained substantial damage to the tailboom, main rotor system, and fuselage. The helicopter was registered to Gitmo Holdings LLC, Stevensville, Montana, and operated by R&R Conner under 14 Code of Federal Regulations Part 133 as an external load logging flight. Visual meteorological conditions prevailed, and no flight plan had been filed. The flight originated at about 1500.
Witnesses reported that when the helicopter was just above the trees, they observed or heard the load of logs release early and impact the ground hard. After looking up, they saw the helicopter's fuselage separate from the tailboom; both descended through the trees. The fuselage impacted the ground inverted, and the tailboom came to rest about 140 feet away. A maintenance worker reported that shortly before the flight, the pilot had landed and shut down for about a 45-minute lunch break. The pilot looked over the helicopter and said it was running really well.
Pilot Information
The pilot, age 53, held a commercial pilot certificate in helicopter, airplane single-engine, and multi-engine land, issued on April 27, 2010. He also held an instrument rating in both helicopter and airplane. He held a second-class medical certificate issued on February 12, 2013, with the limitation that he must wear corrective lenses. According to US Forest Service records dated July 17, 2013, he reported 19,000 total helicopter hours, with 14,000 hours in the accident helicopter make and model.
Aircraft Information
The Garlick helicopter, serial number 62-2034, was originally manufactured by Bell Helicopter as serial number 554 in 1962. It was powered by a T53-L13BA engine. Maintenance logbook records were found within the helicopter but did not contain dates or aircraft total time, so the most recent maintenance could not be determined. The documents revealed that several component inspections were not completed within the manufacturer's recommended time. The hobbs meter read 6,061.3 hours.
According to the FAA, the previous owner relinquished the aircraft's airworthiness certificate to avoid punitive action by the FAA, which had been trying to revoke it due to poor maintenance. In 2010, a new airworthiness certificate was issued to the accident pilot. A different mechanic reported that the helicopter had sat unused for about one month between jobs and was put back in service the day before the accident. The mechanic noted that the pilot had previously indicated the helicopter felt like it "shuffled" during translational lift; the mechanic suspected the transmission mounts were wearing and would need changing later.
Meteorological Information
The nearest weather reporting station, about 38 miles northwest at McNary Field Airport in Salem, Oregon, at 1556 reported wind from 130 degrees at 3 knots, visibility 10 statute miles, broken clouds at 4,900 feet, overcast at 5,500 feet above ground level, temperature 21°C, dewpoint 13°C, and altimeter 29.94 inches of mercury. Remarks stated rain started at 1537 and ended at 1552.
Wreckage and Impact Information
On-scene examination by an FAA inspector revealed the helicopter came to rest on the opposite side of a northwest/southeast oriented dirt road from the log landing site. Terrain was hilly, heavily wooded, and remote. Trees around the accident site sustained limited damage: one tree was topped, others had vertical scrapes. The wreckage debris path extended almost parallel to the dirt road, with four major pieces: the fuselage/transmission, engine, main rotor blades, and tailboom. The fuselage and transmission were found upside down at the southeasternmost point; the engine was nearby. The main rotor head and blades were separated from the main rotor shaft and located about 120 feet northwest of the fuselage. One main rotor blade was embedded in the ground, extending the second blade at a 45-degree angle. The tailboom was separated and located 140 feet northwest of the main rotor blades. The tail rotor gearbox, assembly, and blades were still attached to the vertical fin; one tail rotor blade was mostly undamaged, the other sustained a 45-degree bend away from the fin.
Medical and Pathological Information
An autopsy performed on September 17, 2013, determined the pilot's cause of death as blunt force head trauma. Forensic toxicology by the FAA Civil Aerospace Medical Institute found negative results for carbon monoxide and ethanol. Rosuvastatin, used to treat high cholesterol, was detected in the blood and liver.
Tests and Research
A post-accident examination of the airframe and engine occurred on January 29, 2014. The cabin sustained significant damage; the windscreen, chin bubble, instrument panel, and roof were separated. The aft fuselage was mostly intact with the transmission attached. The tailboom had separated at its attachment points, with skin along the sides showing a "wave" appearance. Control continuity was established except for a segment of the tail rotor drive shaft extending from the transmission, which was not located. The main rotor shaft had fractured just below the main rotor head; the fracture surface was indicative of overload. At the fracture point, the shaft was oblong with impact damage on two opposing sides, and damage to the main rotor blade hub indicated a mast bump event.
The engine was found separated; exhaust and airframe inlet were removed. Organic debris was noted in the engine inlet, and metal spray was found on second stage power turbine nozzle vanes. First stage axial compressor blades and inlet guide vanes had tear and batter damage. Rotation of the power turbine produced corresponding rotation of the engine output shaft and overspeed governor drive gearbox; the engine rotated smoothly. The chip detector was examined with no debris found.
Tailboom attachment points were sent to the National Transportation Safety Board Laboratory. A materials research engineer reported that the top right and left attachment point fittings exhibited fracture surfaces with crack arrest marks and fatigue striations, indicating progressive crack growth. Cracks in the right top fitting initiated near a rivet hole. The left top fitting had cracks through about 75% of the cross-section, with the remaining 15% overstress. The bottom two fittings showed features consistent with overstress failure, with no fatigue indications.