History of Flight
On March 6, 2023, about 2157 central standard time, a Robinson Helicopter Company R-44II helicopter, registration N494SH, was destroyed during an accident near Port O'Connor, Texas. The pilot and passenger were fatally injured. The flight was conducted under 14 Code of Federal Regulations Part 91 as a personal flight.
ADS-B data indicated that earlier that day, the helicopter departed from the pilot's residence in Port O'Connor and flew to Pearland Regional Airport (LVJ) in Pearland, Texas, before returning to the residence. The helicopter was equipped with a Garmin Aera 796 unit, which provided limited data showing a departure from a road next to the residence, traveling northwest before the data ended.
The limited ADS-B data for the accident flight showed the helicopter starting just north of the residence, traveling east over a lake, turning north near a road, climbing, then descending south. The data terminated over an open field next to a home. The distance from departure to the accident site was about 0.25 miles on a northeast heading. The area east of the site consisted of swamp with no observed ground lighting. The helicopter came to rest on a flat grass field, where a postimpact fire consumed most of the wreckage.
According to the passenger's daughter, the intended destination was LVJ. A neighbor about 1,000 ft southwest of the takeoff point observed the helicopter's red anti-collision (strobe) light operating as it departed, reporting that it was "extremely foggy" and she could "barely see" her boat dock about 75 ft away. Another witness estimated visibility about 400 ft due to fog, which arrived around 1900.
Personnel Information
The pilot, a non-instrument-rated medical doctor, attended the RHC Pilot Safety Course in Torrance, California, in September 2008. An RHC flight instructor noted the pilot had a "good attitude to aviation safety" on an evaluation form. The pilot's logbook was not available for review.
Aircraft Information
FAA records showed the pilot purchased the helicopter on June 4, 2008. The helicopter had been involved in a previous accident on February 14, 2014, but the pilot was not on board at that time. The helicopter was equipped for instrument flight but not FAA-certified for instrument flight rules (IFR). It was not equipped with a radar altimeter, nor was one required.
The FAA-approved RHC R-44II Pilot's Operating Handbook states that a red anti-collision light on the tail cone is controlled by the strobe switch, and position lights on the cabin and tail are controlled by the navigation lights switch. The red anti-collision light uses LEDs.
The FAA Pilot's Handbook of Aeronautical Knowledge discusses flicker vertigo, defined as unpleasant reactions to light flickering at 4–20 cycles per second, including nausea, vomiting, vertigo, and occasionally convulsions or unconsciousness. The FAA Helicopter Flying Handbook notes that flashing anticollision strobe lights, especially in clouds, can produce this effect. A 2011 FAA Office of the Chief General Counsel letter agreed that high-intensity anticollision lights could induce vertigo and spatial distortion. 14 CFR Part 91.209 allows pilots to turn off anticollision lights when safety so dictates.
Meteorological Information
The nearest official weather station, Calhoun County Airport (PKV) in Port Lavaca, Texas, about 20 miles northwest, reported at 2155: wind from 160° at 6 knots, visibility 5 miles with mist, and a broken ceiling at 500 ft above ground level. Airmen's Meteorological Information Sierra for IFR conditions was issued at 2200 for ceilings below 1,000 ft and visibility below 3 miles with mist and fog.
The sun was more than 15° below the horizon; the moon was 50° above the horizon at azimuth 109°, with a full moon at 99.7% illumination. The pilot had no contact with Leidos or any third-party weather services, and no weather briefings or flight plans were filed.
Wreckage and Impact Information
Airframe examination revealed flight control continuity. The removable collective and cyclic controls were not installed, but the anti-torque pedals were installed. The navigation light switch and anti-collision (strobe) light switch were in the on positions. Cockpit warning lights were intact with no filament stretching. An unknown-model emergency locator transmitter was found with fire damage, antenna connected, and mounted to the airframe.
Due to fire and impact, airframe-to-engine control continuity could not be confirmed. Engine examination showed internal continuity; crankshaft rotation via the cooling fan confirmed continuity to the rear gear and valvetrain. Compression and suction were observed from all six cylinders, and borescope inspection revealed no piston, cylinder wall, or valve damage.
Medical and Pathological Information
The Travis County Medical Examiner's Office performed an autopsy, listing blunt trauma as the cause of death, with the manner accidental. The heart showed ventricular and atrial dilatation and was described as enlarged; coronary arteries were normal. No other significant natural disease was noted. Postmortem toxicology detected no ethanol, common drugs of abuse, or elevated carbon monoxide. FAA Forensic Sciences Laboratory testing found ethanol in cavity blood at 0.012 g/dL, but not in vitreous fluid or urine; n-propanol and acetone were detected in cavity blood only. Cetirizine was found in cavity blood (121 ng/mL) and urine (794 ng/mL). Norchlorcyclizine, sildenafil (urine only; blood inconclusive), desmethylsildenafil, and acetaminophen were also detected.
Additional Information
RHC Safety Notice SN-26, "Night Flight Plus Bad Weather Can Be Deadly," states that in darkness, pilots cannot see wires, clouds, or fog, and without a horizon, cannot judge altitude, leading to loss of control. It advises night flight only with clear weather and ample ground or celestial lights.
The FAA Civil Aeromedical Institute defines spatial disorientation as confusion about position or movement relative to Earth, contributed to by acceleration changes, flight in instrument meteorological conditions (IMC), frequent VMC/IMC transitions, and unperceived attitude changes. The FAA Helicopter Flying Handbook notes that inadvertent IMC (IIMC) can cause physiological illusions leading to spatial disorientation and loss of control. Night flying requires conservative personal minimums due to difficulty detecting deteriorating weather.
The helicopter was not equipped with a crashworthy flight data recorder, nor was it required.