History of Flight
On December 29, 2021, at 1425 eastern standard time, a Robinson Helicopter Company R-44 II, registration N544SC, sustained substantial damage in an accident near Cosby, Tennessee. The commercial pilot received serious injuries; the passenger was fatally injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The pilot and passenger had traveled from Utah to retrieve the helicopter after leasing it. They arrived at the service center where the helicopter was stored around 0830. The pilot reviewed the lease agreement and performed a local flight in the Gatlinburg-Pigeon Forge Airport (GKT) traffic pattern to assess the helicopter.
Weather conditions throughout the day were described by service center personnel as changing from marginal VFR to IFR conditions. The pilot was cautioned by employees about the dangers of flying in the Smoky Mountains in marginal weather. One employee showed him a book of controlled flight into terrain accidents in the area; the pilot replied, "those are hills," and noted his 14 years of mountain flying experience. A local helicopter air ambulance pilot also spoke with the pilot, who intended to depart towards Asheville and follow Interstate 40 through the gorge to Raleigh, North Carolina. The air ambulance pilot warned that mountains east of GKT reached 6,000 ft and powerlines existed above the I-40 gorge.
The pilot and passenger departed GKT eastbound at about 1413. Federal Aviation Administration radar data indicated the helicopter flew through valleys in an easterly/southeasterly direction at altitudes between 1,200 ft and 1,750 ft, but data was not continuous.
A GoPro camera mounted in the cockpit recorded the flight. The video began at 1414:54, showing rising terrain ahead with mountain top obscuration. The cloud layer appeared broken at the helicopter's position but thickened ahead. As the helicopter approached an area of low visibility and rising terrain, it continued a gradual ascent. At 1424:34, visibility decreased greatly. The helicopter's groundspeed and indicated airspeed initially decreased, reaching a minimum of less than 20 knots by 1424:48. Manifold pressure was reduced, then increased as airspeed decreased. The helicopter then pitched forward, airspeed increased slightly. Visibility further decreased to zero at 1425:07. Manifold pressure went beyond the red arc to about 27 inHg. The helicopter pitched forward and airspeed rapidly increased to about 85 knots, with manifold pressure steadily above the red arc. The helicopter then yawed rapidly to the right, airspeed displayed zero knots, and altitude decreased. The low rotor rpm warning light and aural warning activated.
The helicopter emerged from the cloud layer in a right roll and right yaw, which quickly reversed to a left roll and left yaw. It then descended rapidly into trees, impacting the tops in a left yaw and level roll condition. Main rotor blades struck tree branches and trunks. The low rotor rpm (yellow) and low engine oil pressure (red) lights illuminated during impact. The helicopter came to rest among trees at ground level.
No evidence in the recording suggested preimpact mechanical malfunctions or failures before entering extremely low visibility.
Personnel and Aircraft Information
The pilot's total flight experience was based on a first-class medical certificate application dated December 7, 2021. A water-damaged logbook was found but was partially illegible, so total flight time could not be determined.
The helicopter was not certificated for flight in instrument meteorological conditions.
Wreckage and Impact Examination
The helicopter came to rest on a heading of 210° on steep, wooded terrain. There was no fire. The cabin was crushed forward with the tail boom raised behind. The tail rotor was separated and on the right side. All airframe, main rotor, tail rotor, and powerplant components were accounted for. Main and auxiliary fuel tanks remained attached; the auxiliary tank appeared full. Fuel from both tanks showed no contamination. Flight control continuity was confirmed.
The engine remained attached with minor impact damage. No oil or fuel residue was present. No evidence of in-flight oil loss was found. Main rotor blades were attached; one blade was bent but complete, the other bent and separated into three pieces, with about 3 ft of the tip separated.
At the salvage facility, the engine was examined further. The engine-driven fuel pump drain line fitting was impact-separated. The fuel strainer was impact damaged but clean. Upper spark plugs were removed and crankshaft continuity was confirmed. Borescope inspection showed no piston or valve damage. An external fuel source was connected; when the electric fuel pump was energized, fuel leaked around the fuel injector servo throttle shaft, which was bent consistent with impact. The engine oil pressure gauge indicated about 60 PSI when the crankshaft was rotated. The fuel injector servo was impact damaged, but diaphragms were intact and screens unobstructed. Both magnetos produced spark. Spark plug electrodes showed normal wear except some oil-soaked electrodes. The oil dipstick showed about 5 quarts; no oil was observed externally. The oil suction screen and filter were absent of debris.
Examination found no malfunctions or anomalies that would have precluded normal operation.