History of Flight
On November 3, 2018, about 2347 Central Standard Time, a Bell 206B helicopter (N417WT) was destroyed when it struck a hillside near Uvalde, Texas. The pilot and two passengers were fatally injured. The flight was conducted under 14 CFR Part 91 as a personal flight in night visual meteorological conditions.
Data from the helicopter's primary and multifunction display units showed that the helicopter departed a private ranch at about 2341 and proceeded east toward San Antonio. The helicopter climbed to 1,900 ft altitude, then gradually descended. The final recorded barometric altitude was 1,538 ft with an airspeed of 74 knots. The altimeter was set to 30.05 inHg. The data did not indicate extreme changes in pitch, bank, or airspeed. The last GPS altitude recorded was 1,422 ft. The terrain awareness warning system (TAWS) and helicopter TAWS low-altitude alerts were configured for 140 ft above ground level, but terrain alerts were set to inhibit.
Search efforts began after the Uvalde County Sheriff's Office was notified of a possible downed aircraft northwest of Uvalde. The wreckage was located at daybreak the following morning about 5 miles east of the departure point and about 71 miles west of San Antonio International Airport. The helicopter impacted about 100 ft below the apex of a hill measuring about 1,500 ft mean sea level. A wreckage path 75 to 100 yards long was distributed along the hillside. No post-crash fire occurred.
Pilot Information
A review of the pilot's previous aviation medical examinations noted a diagnosis of early cataracts, but no additional information on the severity was available.
Weather Information
Weather conditions near the time of the accident included a small area of cloud ceilings east of the departure point, which dissipated and moved eastward. There was no indication of low-level wind shear or clear air turbulence. There was no record of the pilot receiving a weather briefing before departure. Moonrise was at 0343 and moonset at 1642, with about 19% of the disk illuminated. At the time of departure and the accident, the moon was below the horizon.
Wreckage Examination
Due to hazardous terrain, an on-scene examination was not possible; the wreckage was recovered to a secure facility. All major components were located. The forward cabin/cockpit area was largely destroyed by impact. The tail boom remained attached but was twisted and damaged. The fuel bladder contained an undetermined quantity of fuel. The tail rotor gearbox was found several feet away; both tail rotor blades were bent but remained attached. No anomalies were noted in the tail rotor gearbox, and oil was present.
The main rotor hub and blade assembly had separated from the main rotor mast below the hub. The mast showed a fracture consistent with mechanical overload. The two main rotor blades were fractured outboard of the doublers and found near the wreckage path. Main rotor drivetrain continuity was established by rotating the input drive by hand; no abnormalities were noted. Transmission chip detectors showed no particles.
Hydraulic system components sustained impact damage, but a small amount of hydraulic fluid was present. The three servo actuators remained attached and moved when manipulated by hand. No preimpact abnormalities were noted. Flight control continuity could not be established due to impact damage, but no anomalies were observed with the collective, cyclic, and anti-torque pedals. Airframe examination revealed no evidence of preimpact abnormalities.
The engine was removed and examined at an overhaul facility. Continuity was established through the accessory section. Foreign object damage was noted on leading edges of intake compressor blades, and metal spray was observed on the turbine compressor wheel. The engine bleed valve and fuel nozzle were bench tested. The power turbine governor and fuel control units were tested separately. No engine abnormalities that would have restricted normal operation were found.
Medical Examination
The Bexar County Medical Examiner's Office conducted an autopsy on the pilot, determining the cause of death as multiple blunt force injuries. Toxicological testing at the FAA Forensic Sciences Laboratory was negative for ethanol; desmethylsildenafil (an active metabolite of sildenafil) was detected in muscle and liver but is not considered impairing. Specimens were not tested for cyanide or carbon monoxide.