History of Flight
On January 17, 2018, about 1800 mountain standard time, a Bell UH-1H helicopter, N658H, impacted terrain near Raton, New Mexico, and was subsequently consumed by a postimpact fire. The helicopter was destroyed. The flight originated from Raton Municipal Airport/Crews Field (RTN) about 1750, destined for Folsom, New Mexico, as a Title 14 Code of Federal Regulations Part 91 personal flight. Night visual meteorological conditions prevailed, and no flight plan was filed.
A surviving passenger reported that the group boarded a private airplane in Houston, Texas, flew to Raton, then boarded the company helicopter for a personal function in Folsom. The takeoff was normal. As they flew east, the sun had set and stars were bright. No turbulence, unusual noises, or warning lights were observed. The pilot and copilot appeared calm. The passenger recalled level flight until she heard a loud bang as the helicopter hit the ground. After ground contact, the helicopter rolled forward and came to rest upside down. The passenger released her seat belt and egressed; the helicopter was on fire and subsequent explosions occurred.
According to a first responder, arrival at the accident site was about 2000, with paramedics arriving about 2015. The pilot initially survived the accident but succumbed to his injuries en route to a hospital. A witness reported that before being loaded into a rescue helicopter, the pilot said the accident was his fault and that he had flown into terrain.
Personnel Information
The pilot held a commercial pilot certificate with ratings for airplane single-engine land, rotorcraft-helicopter, and instrument helicopter. He held an FAA second-class medical certificate issued December 7, 2017, with a limitation requiring corrective lenses for distant vision and glasses for near vision. He reported 6,416 total flight hours, with 44 hours in the preceding six months, and 2,065 hours in UH-1 helicopters on an insurance questionnaire.
The pilot-rated passenger held a commercial pilot certificate with a rotorcraft-helicopter rating and a second-class medical certificate issued December 11, 2017, with limitations requiring corrective lenses and a validity end date of December 31, 2018. He reported 3,140 total flight hours, 30 hours in the preceding six months, and 120 hours in UH-1 helicopters.
Aircraft Information
N658H was a Bell UH-1H helicopter, serial number 67-17658, manufactured in 1967. The current type certificate holder is Rotorcraft Development Corporation. It was a single-engine helicopter powered by a Honeywell T53-L-703 turboshaft engine (serial LE-10462Z) with a two-bladed main rotor and tail rotor. The engine had a maximum continuous rating of 1,300 shaft horsepower at 6,634 rpm.
The helicopter was certificated as a restricted category aircraft for external load operations. Title 14 CFR 91.313 restricts passenger carriage to flight crewmembers, trainees, or those essential for special purpose operations. The helicopter had accumulated 4,420.5 total hours as of January 9, 2018. It had seven previous civilian owners before Sapphire Aviation, LLC purchased it on February 10, 2017.
Meteorological Information
At 1753, the recorded weather at RTN included wind 030° at 10 knots, visibility 10 statute miles, clear sky, temperature 1°C, dew point -18°C, and altimeter 30.26 inches of mercury. According to the U.S. Naval Observatory, local civil twilight ended at 1735, moonset was at 1754, and the moon was a waxing crescent with 0% illumination.
Wreckage and Impact Information
The main wreckage came to rest on a flat mesa about 10.7 nautical miles and 102° from RTN at an elevation of about 6,932 ft mean sea level. Initial ground scars, consistent with skid width, led to the wreckage on a 074° magnetic bearing over 474 ft. About 18 ft beyond the end of the scars was a 25-ft-long ground scar consistent with a main rotor blade slap, perpendicular to the path. The main rotor came to rest about 60 ft beyond the blade slap, and the tail rotor and gearbox were nearby. The fuselage was located about 66 ft beyond the main rotor, upside down, with the cabin section destroyed by fire.
The right side of the cockpit sustained thermal damage. Left-side controls were in place but collective broke from its mount. Right-side controls were separated or missing. Control tubes aft of the cockpit were destroyed by fire. Two altimeters were recovered: one indicated 6,760 ft (Kollsman 30.18), the other 6,000 ft (Kollsman 30.28). The transmission and main rotor mast were present; the transmission case was consumed by fire, but the main drive gear was intact. The engine displayed no penetrations of the combustor plenum, but metal spray deposits were on second-stage power turbine stator vanes. The tail rotor and drive shaft segments were found with oil present. Main rotor blades separated from the mast with torsional overload fractures; both blades had broomstraw appearance at tips.
Medical and Pathological Information
An autopsy of the pilot determined the cause of death as blunt force trauma with atherosclerotic and hypertensive cardiovascular disease as contributing conditions. The pilot's heart was enlarged with thickened ventricles; severe coronary artery disease (up to 75% stenosis in the left anterior descending artery) and microscopic evidence of previous ischemia were found. Toxicology testing detected etomidate (administered post-accident) in heart blood and 0.032 µg/mL of diphenhydramine in femoral blood. Diphenhydramine is used for colds and hay fever, with warnings about impaired mental/physical ability; therapeutic range is 0.0250 to 0.1120 µg/mL.
Tests and Research
A cellphone and iPad from the wreckage were examined by the NTSB but were locked, so no data was retrieved. Terrain mapping and viewpoint flights using a small unmanned aircraft system revealed that fewer visible terrain features were present at night compared to day. A review of local terrain indicated that a direct route from RTN to the destination would have been about 450 ft lower; the accident site was about 4 nautical miles south of that route.