NTSB Factual Report

HISTORY OF FLIGHT

On August 31, 2010, about 0929 Pacific daylight time (PDT), a Hiller UH-12E helicopter, N67264, was substantially damaged when it impacted utility lines, a travel trailer, and the ground in Kamiah, Idaho, about 35 minutes after departure. The commercial pilot and the two passengers, both of whom were biologists with the Idaho Department of Fish and Game (IDFG), were fatally injured. The helicopter was owned by Leading Edge Aviation (LEA), and was under the operational control of IDFG as a wildlife survey flight. The flight was conducted under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91, and in accordance with the IDFG Clearwater Region "Regional Summary of Procedures for Monitoring Low Level Aerial Survey Operations," dated December 31, 2009. Visual meteorological conditions prevailed. A notification for automated flight following (AFF) was filed and activated with the Idaho State Communications Center, referred to as "StateComm."

The biologists arrived at the LEA helicopter base, Skid Row Seaplane Base (WT33) Clarkston, Washington, about 0800. Flight preparations and briefings were conducted, and most of the biologists' gear was secured in cases on external racks on the helicopter. The plan was for the helicopter to fly about 70 miles to the east to rendezvous with an LEA fuel truck, refuel, and then conduct the survey. The pilot seated himself in the center seat, the female biologist was in the right seat, and the male biologist was in the left seat. The helicopter departed WT33 about 0850, and the first AFF return from the helicopter was received about 6 minutes after that. About 33 minutes later, StateComm received a radio call from the helicopter, announcing that it intended to land in Kamiah. No explanatory or additional transmissions were received from the helicopter.

Kamiah was a small town situated about 30 miles short (west) of the planned fuel stop. Several eyewitnesses in Kamiah reported that they first observed the helicopter transiting west to east. They then heard unusual noises emanating from the helicopter, and observed objects separating or falling from the helicopter. Several noted that the helicopter was gyrating or rotating about its longitudinal or vertical axes, and that the trajectory steepened as the helicopter descended. The main wreckage, which consisted of the cabin, tail boom and main rotor system, impacted in a driveway of a residence. Two of the occupants received immediate fatal injuries, while the third survived for several minutes after the impact.

A debris path that was oriented back (west) along the helicopter's flight path, and that measured approximately 1,500 feet in length, was comprised of various items from the helicopter. Some of the earliest items in the debris path included the tail rotor blade and tail rotor gearbox segments, and fragments of a metal clipboard that belonged to one of the biologists.

PERSONNEL INFORMATION

The pilot was an employee of LEA. He held a commercial pilot certificate with a helicopter rating. According to information provided by LEA, he had approximately 9,000 total hours of flight experience, all of which was in helicopters, and which included approximately 300 hours in the accident helicopter make and model. His most recent flight review was completed in October 2009, and his most recent Federal Aviation Administration (FAA) second-class medical certificate was issued in October 2009.

The Lewis County (Idaho) Coroner's Office autopsy report indicated that the cause of death was "blunt force trauma." The FAA Civil Aeromedical Institute conducted forensic toxicology examinations on specimens from the pilot, and reported that no carbon monoxide, cyanide, ethanol, or any screened drugs were detected.

According to IDFG information, the pilot was properly "carded" (trained and approved by the Aviation Management Directive (AMD) of the National Business Center (NBC) of the United States Department of the Interior, in accordance with IDFG contractual requirements) and was current with regard to all other IDFG qualifications. The flight was the first scheduled flight of the day, and the pilot was within the duty day and other crew requirements or limitations established by the contract. The pilot and both biologists were wearing the required aviation life support equipment at the time of the accident. Both biologists were current with respect to their IDFG-required aviation safety training, and both had an extensive history of low altitude flights.

The male biologist was a private pilot with approximately 10 years of flight experience, and owned a single-engine airplane. He also had about 10 years of experience with the same type of survey that was planned for the accident flight; most of those flights were conducted in helicopters.

Also according to IDFG information, the female biologist had conducted extensive low-altitude fixed-wing survey flying between the years 2000 and 2004. It was reported by some IDFG personnel that she may have been susceptible to airsickness, but no definitive evidence or documentation of this was provided for the investigation.

Autopsies were not conducted on either biologist.

AIRCRAFT INFORMATION

Overview

According to FAA records, the helicopter was manufactured in 1965, and was converted to turbine power in 1981. Information provided by LEA indicated that at the time of the accident, the helicopter had accumulated a total time (TT) in service of 7,388 hours. Review of maintenance records indicated that the most recent annual inspection was completed in April 2010. At that time, the airframe had a TT of 7,168 hours, while the engine had a TT of 7,432 hours. The most recent 100-hour inspection was completed in July 2010, and the helicopter had accumulated about 80 hours in service since that inspection.

General Configuration Information

The basic configuration consisted of 3-place-abreast seating in a metal-frame and plastic transparency "bubble cabin," a two-bladed metal main rotor, and a two-bladed metal tail rotor (painted red). Specific configuration details included:

- A metal "seat deck"' which was the primary structural element of the cabin

- Metal-framed left and right side cabin doors

- A vertical firewall that also served as the aft cabin wall

- A central pilot's seat with an instrument/control pedestal, and flight controls

- Left and right external racks (approximately 6 feet long, 2 feet wide, and 4 inches deep, with metal mesh bottoms)

- Main rotor rotation counter-clockwise when viewed from above

- A metal, semi-monocoque tail boom

- Multi-segment tail rotor drive system mounted atop the tail boom

- Tail rotor gearbox at the aft end of the tail boom

- Tail rotor rotation counter-clockwise when viewed from helicopter left side

- Single metal horizontal stabilizer on the right-side end of the tail boom

METEOROLOGICAL INFORMATION

The 1030 automated weather observation at Kamiah Municipal Airport (S73), Kamiah, included calm winds; clear skies; temperature 16 degrees C; dew point 10 degrees C; and a barometric pressure of 29.99 inches of mercury. Visibility values were not recorded, and no precipitation was recorded in the 12 hours preceding the accident.

AIDS TO NAVIGATION

A handheld Garmin GPSMap 396 global positioning system (GPS) unit was found in the main wreckage, and mounting, antenna, and power provisions for the unit were attached to the helicopter. The unit was recovered and shipped to the NTSB Recorder Laboratory in Washington DC. Data downloaded from the GPS unit indicated that a pre-stored route entitled "Skid Row - S73" was active for the flight.

COMMUNICATIONS

"StateComm"

According to its website, StateComm was an emergency communications center that operates continuously, to provide emergency dispatch and communications for State and public health- and safety-related situations or emergencies. Partner agencies included the Idaho Transportation Department, Idaho State Police, and IDFG.

The StateComm network had provisions for both automated tracking of subject aircraft, as well as radio voice communications between the aircraft and the network personnel/offices. Typically, aircraft operating on missions of concern to StateComm were monitored via the AFF system, which was a GPS and satellite/web-based system whereby the dispatcher could monitor an aircraft via computer in real time; data associated and presented with the aircraft icon included aircraft location, speed, heading, altitude, and flight history. The StateComm AFF system required dedicated hardware on the aircraft, and required each AFF/ GPS unit to be set up so that it would automatically broadcast aircraft position data at an interval of once every 2 minutes.

The aforementioned IDFG Clearwater "Procedures Summary" stated that "AFF should be used whenever possible" for IDFG survey flights, and recommended the use of StateComm for AFF services. Filing and activating AFF was the responsibility of the "individual responsible for initiating the survey." The Procedures Summary stated that the "flight follower must be contacted when taking off and at least every 30 minutes following, or whenever a major change in flight location is taking place. Flight follower must be informed of every landing and takeoff unless other arrangements have been made. Flight follower must be contacted when flight is terminated. If the aircraft fails to make contact within one-half hour of the scheduled time, the flight-following service will initiate a search and rescue operation."

StateComm Documentation Time Discrepancies

The investigation was provided with two documents and one position data file by StateComm regarding the accident flight. The document entitled "Flight Following Incident" contained the AFF-related information for the flight, while the other one ("M-2010-00070") chronicled the StateComm ground-based communications regarding the flight. The data file contained 6 flight data points, and each data point included position and time information. All "time" information was manually entered by StateComm personnel. Both documents contained multiple entries with "time" information, but neither contained any reference to a particular time zone. In addition, both documents contained internal contradictions regarding "time;" the "creation" or "print" times were prior to some of the event time stamps on the documents. However, the data file did specify time zone references. Since StateComm was based in Meridian, Idaho, which was in the mountain time zone, and the accident flight took place in the Pacific time zone, the time stamps associated with the flight itself were presumed to be stated in mountain time, which placed them in alignment with the times in the data file.

Accident Helicopter StateComm Communications

According to the StateComm "Flight Following Incident" printout for the accident helicopter, an "AFF active" communication was received from the flight at "1004" (0904 PDT), and the transmitted geographic coordinates indicated that the helicopter was 10.6 nm, on a bearing of 093 degrees true, from WT33. At "1029," (0929 PDT) a "landing in Kamiah" communication was received from the flight. The StateComm geographic coordinates associated with that broadcast indicated that the helicopter was 11.6 nm, on a bearing of 293 degrees true, from the accident location. Review of available data indicated that that position for the "landing" radio call was not valid.

The time specified in the StateComm AFF synopsis document for the "landing" radio call was 0929 (adjusted to Pacific time zone), which was also about the same time as the last GPSMap-recorded time, and very close to the time of the accident. Further evaluation of the data revealed that the position data associated by StateComm personnel with the "landing" call was actually the last AFF position data that had been received from the helicopter, and was at least 6 minutes old, and the position Since the actual AFF position interval was incorrectly set (see following paragraphs), that last position data was significantly older/less current than it was supposed to be. However, since it was still the most recent data available to StateComm, it was utilized as the position location for the "landing" call, which conflicts with other position and time information regarding the flight.

According to a representative of the Aviation Management Directive (AMD) of the National Business Center (NBC) of the United States Department of the Interior, the StateComm records provided to the investigation were the only records available. Therefore, neither the exact time, nor the exact location of the helicopter for the "landing in Kamiah" radio call could be determined.

StateComm document M-2010-00070 indicated that about "1045," (0945 PDT) a representative of LEA telephoned StateComm to confirm that StateComm was "flight-following" the helicopter. When StateComm responded that it was following the helicopter, the LEA representative informed StateComm that "the helicopter was no longer active on AFF" for LEA. StateComm then informed LEA that the pilot radioed that he was landing in Kamiah, and that the AFF data icon at StateComm was "red," which indicated that it was more than 15 minutes since StateComm had received any position information from the helicopter. Subsequent attempts by StateComm, at the request of the LEA representative, to communicate with the helicopter were unsuccessful. About "1058," (0958 PDT) the Lewis County Sheriff office notified StateComm that a helicopter with registration N67264 had crashed in Kamiah, and that there were two fatalities.

Review of IDFG guidance regarding flight following procedures revealed that once airborne, IDFG flight personnel were required to notify StateComm whenever they intended to change the route of flight, or conduct a landing at a location other than that originally specified. However, the guidance did not require the provision or solicitation of any additional amplifying information, such as the reason for, or the timing of, the changes. The guidance also required flight personnel to notify StateComm after every landing, but the guidance did not specify a time window (after the landing) for the notification.

Helicopter AFF Data Transmission Interval

Post-accident examination of the AFF position tracking data from the accident helicopter revealed that its AFF/GPS unit had remained set to the manufacturer's default broadcast interval setting of 6 minutes, instead of the 2-minute interval specified as an IDFG contractual requirement. According to the AMD/NBC representative, resetting of the broadcast interval to the StateComm standard was the responsibility of the aircraft operator. It could not be determined why LEA did not reset the accident helicopter's AFF/GPS broadcast interval.

WRECKAGE AND IMPACT INFORMATION

General

The area immediately surrounding the main wreckage impact site was residential. The impact site was located about 1 mile northwest of S73. The overall debris field extended approximately 1,500 feet, with a primary axis from west to east. The main wreckage was situated in a compact area surrounded by tall trees and utility poles. The trees, approximately 60 feet tall, and approximately 15 to 20 feet from the main wreckage, had no significant signs of damage. The helicopter tail boom impacted a travel trailer parked in a driveway, and one main rotor blade sliced completely through the trailer. The engine remained attached to its mounts. The transmission, mast and both main rotor blades were present at the main wreckage site. The tail boom was angled about 40 degrees aft-end up, and the aft end rested on the travel trailer. Its forward end remained attached to the helicopter structure. The canopy frame and transparencies were fracture-separated into multiple pieces; many were found forward of the cabin.

Lewis County Sheriff (LCS) personnel, in conjunction with IDFG and Idaho Department of Lands (IDL) personnel, located, mapped with GPS, and recovered the wreckage components from the outlying debris field. The items were then transferred to the NTSB investigators at the main wreckage location, where they were

NTSB Probable Cause

In-flight impact of a passenger's metal clipboard with the helicopter’s tail rotor, which resulted in destruction of the tail rotor and subsequent loss of control of the helicopter. The original location of the clipboard and how it became free could not be determined.