History of Flight
On August 31, 2010, about 0929 Pacific daylight time, a Hiller UH-12E helicopter, registration N67264, was substantially damaged when it impacted utility lines, a travel trailer, and the ground in Kamiah, Idaho. The commercial pilot and two passengers, both biologists with the Idaho Department of Fish and Game (IDFG), were fatally injured. The helicopter was owned by Leading Edge Aviation (LEA) and under the operational control of IDFG as a wildlife survey flight. The flight was conducted under Title 14 Code of Federal Regulations Part 91 and in accordance with IDFG procedures. Visual meteorological conditions prevailed. An automated flight following (AFF) notification was filed with the Idaho State Communications Center (StateComm).
The biologists arrived at the LEA helicopter base at Skid Row Seaplane Base (WT33) in Clarkston, Washington, about 0800. Flight preparations were made, and gear was secured in cases on external racks. The plan was to fly about 70 miles east to refuel and then conduct the survey. The pilot occupied the center seat, the female biologist the right seat, and the male biologist the left seat. The helicopter departed about 0850. About 33 minutes later, StateComm received a radio call from the helicopter announcing an intent to land in Kamiah. No further transmissions were received.
Eyewitnesses in Kamiah observed the helicopter transiting west to east, then heard unusual noises and saw objects separating from it. The helicopter was seen gyrating or rotating, and its trajectory steepened as it descended. The main wreckage, including the cabin, tail boom, and main rotor, impacted in a residence driveway. Two occupants received immediate fatal injuries; the third survived several minutes after impact. A debris path approximately 1,500 feet long stretched west, containing tail rotor blade fragments and parts of a metal clipboard.
Personnel Information
The pilot, an LEA employee, held a commercial pilot certificate with helicopter rating and had about 9,000 total flight hours, including about 300 in the accident make and model. His most recent flight review was in October 2009, and his FAA second-class medical was issued the same month. The Lewis County Coroner's Office listed cause of death as blunt force trauma. FAA toxicology on the pilot found no carbon monoxide, cyanide, ethanol, or screened drugs. The pilot was properly carded and current for IDFG qualifications. The flight was his first of the day and within duty limits. All three occupants wore required aviation life support equipment. Both biologists were current in IDFG safety training and had extensive low-altitude flight experience. The male biologist was a private pilot with about 10 years of experience, and the female biologist had conducted low-altitude fixed-wing survey flying between 2000 and 2004; some personnel reported she might be susceptible to airsickness, but no definitive evidence was provided. Autopsies were not performed on the biologists.
Aircraft Information
The helicopter, manufactured in 1965, was converted to turbine power in 1981. At the accident, total time was 7,388 hours. The most recent annual inspection was in April 2010, and the most recent 100-hour inspection was in July 2010, with about 80 hours since. The helicopter had three-place-abreast seating in a bubble cabin, two-bladed main rotor, and two-bladed tail rotor painted red. Specific configuration included a metal seat deck, metal-framed doors, a central pilot's seat with controls, and left and right external racks. The main rotor rotated counter-clockwise when viewed from above; the tail rotor rotated counter-clockwise when viewed from the left side. A single horizontal stabilizer was on the right side of the tail boom.
Meteorological Information
The 1030 automated observation at Kamiah Municipal Airport (S73) included calm winds, clear skies, temperature 16°C, dew point 10°C, and barometric pressure 29.99 inches of mercury. No visibility or precipitation data were recorded.
Aids to Navigation
A handheld Garmin GPSMap 396 GPS unit was found in the main wreckage; data showed a pre-stored route named "Skid Row - S73" was active.
Communications
StateComm, the emergency communications center, provided AFF tracking and radio communications. The IDFG procedures required AFF use when possible and contact with flight followers at least every 30 minutes. Two documents and a data file were provided. Time discrepancies existed: the documents had internal contradictions and lacked time zone references, but the data file specified mountain time. The flight's AFF active was received at 0904 PDT; at 0929 PDT, a "landing in Kamiah" call was received, with coordinates placing the helicopter 11.6 nm from the accident site on a bearing of 293 degrees true—but those coordinates were not valid. The last AFF position data were at least 6 minutes old due to an incorrectly set broadcast interval. The helicopter's AFF unit remained at the default 6-minute interval instead of the required 2 minutes; the aircraft operator was responsible for resetting.
At about 0945 PDT, an LEA representative called StateComm, who reported the pilot had radioed landing in Kamiah and that the AFF icon was red (over 15 minutes since last data). Subsequent attempts to contact the helicopter failed. At about 0958 PDT, the Lewis County Sheriff notified StateComm of a crash with two fatalities.
Wreckage and Impact Information
The residential impact site was about 1 mile northwest of S73. The debris field extended 1,500 feet west to east. The main wreckage was surrounded by tall, undamaged trees. The tail boom impacted a travel trailer; one main rotor blade sliced through it. The engine remained attached. The cabin was upright but heavily damaged, with lateral loading from the right. Ground scars indicated minimal right travel. The main rotor blade that cut the trailer was angled about 30 degrees from horizontal, consistent with a right-side-down impact attitude. All three seats had multi-point restraints; each inertia reel was functional, and all occupants were properly secured and wearing flight helmets.
The lead-acid battery was found about 600 feet south of the debris axis. The left cabin door remained attached; its handle was found in the open position one day after the accident. The right door was fracture-separated; its handle also in open position. Both handles were free to rotate. The left door's strike plate was undamaged; the right door's tab was bent. The fuel caps were secure; the main tank was compromised and empty; auxiliary tanks were ruptured and empty. Main rotor control continuity was established with overload failures consistent with ground impact. The tail boom, tail rotor drive, and tail rotor were fragmented; the tail rotor and gearbox were among the earliest debris. Damage was consistent with main rotor blade strikes on the tail boom. The tail rotor drive shaft showed torsional failure and blade impact, with no pre-existing damage. The tail rotor hub and gearbox remained attached but separated; gearbox movement struck the horizontal stabilizer. One tail rotor blade had leading edge crush damage consistent with impact with a metal clipboard found nearby. Anti-torque pedal continuity was partially established but full travel was restricted; components were accounted for.
The engine was an Allison 250 C20 gas turbine, but no further details were provided.
Other Information
The investigation had no explicit statement of probable cause.