# NTSB SEA03LA189: Bell 47G-3B-1, N48020, Diamond, OR, September 12, 2003 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: September 12, 2003, 09:20 local (16:20 UTC) - Place: Diamond, OR - Coordinates: 43.001667, -118.585556 - Nearby events: https://openairdocs.org/map.md?lat=43.0017&lon=-118.5856&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report March 30, 2004 - Report: Approved by Office Director - Parties: FAA-FSDO - NTSB case key (mKey): 57932 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA03LA189 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/57932/pdf - Page: https://openairdocs.org/ntsb/SEA03LA189 ## Probable cause Loss of engine power for undetermined reasons during hover. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, hover - reason for occurrence undetermined (cause) - Forced landing, emergency descent/landing - In flight collision with terrain/water, emergency descent/landing - terrain condition - ground ## Analysis During a flight for the purpose of herding horses into a trap, the helicopter was in a hover about 80 feet above ground level. The pilot reported that as he transitioned from the hover to forward flight he noted that the rotor rpm was decaying and the engine rpm increased rapidly. The pilot entered into an autorotation with a rapid descent. The helicopter landed hard, collapsing the main landing skids and the main rotor blades contacted and severed the tail boom. The helicopter came to rest with the engine still running. A wrangler assisted the pilot in turning off the magnetos. Several individuals in the area reported hearing the engine sound go from a normal sound to a high pitch just prior to the collision. An individual who was video taping the activity also captured the sound of the engine go to a high pitch just prior to the sound of the collision. After wreckage recovery, the engine, transmission, clutch and freewheeling systems were inspected and no evidence of a mechanical failure or malfunction was found. ## Factual narrative On September 12, 2003, approximately 0920 Pacific daylight time, a Bell 47G-3B-1, N48020, registered to the pilot, doing business as High Desert Helicopters as a 14 CFR Part 91 flight for the purpose of herding horses into a trap for the Bureau of Land Management, landed hard near Diamond, Oregon. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local flight. The helicopter was substantially damaged and the commercial pilot, the sole occupant, was seriously injured. The flight had been operating in the area for about twenty minutes prior to the accident. In a written statement, the pilot reported that he was in a hover about 80 feet above ground level observing the horses that he was herding into a trap. The pilot stated that as he started to transition from the hover to forward flight, he noticed that the rotor rpm was decaying and the engine rpm increased rapidly. The pilot immediately rolled the throttle off and reduced collective pitch to enter an autorotation. Due to the decreased airspeed, the helicopter descended rapidly. Approximately 20 to 30 feet agl, the pilot added collective pitch control to control the rapid descent, however the helicopter landed hard. The main landing skids collapsed and the main rotor blades contacted and severed the tail boom. The helicopter came to rest with the engine still running on its tail and left side, nearly inverted with the nose high. A ground crew member (wrangler) in the local vicinity aided the pilot and was instructed to turn off the magnetos. Several people involved with the herding of the horses reported that they did not see the crash sequence due to terrain. Several did hear the helicopter's engine noise change to a "high pitch" sound just before the sound of the collision. An individual video taping the herding activity captured the sound of the helicopter engine, however, due to the terrain, did not have the aircraft in sight. The video verifies the engine sound going from a normal sound to a sudden high pitch, followed immediately by the sound of the collision. At the time of the accident, the temperature was reported at 65 degrees F. The wind velocity was about 8 knots, with gusts to 12 knots. The altimeter setting was 29.98" Hg. The accident site elevation is 4,700 feet mean sea level. Density altitude for the reported conditions were calculated as 6,087 feet. The wreckage was removed from the accident site and transported to Fallon, Nevada. An inspector from the Reno, Nevada, Flight Standards District Office inspected the helicopter. The inspector reported that the engine, transmission, clutch and freewheeling systems were inspected. No evidence of a mechanical failure or malfunction was found. The tach indicator was found inoperative and sent out to a facility for inspection. During the inspection it was found the unit was bound from impact damage. ## Aircraft - Registration: [N48020](https://openairdocs.org/aircraft/N48020), registered now, S/N 2812, built 1967 (OpenAirDocs) - Reported make and model: Bell 47G-3B-1 - Registry model: [Bell 47G-3B-1](https://openairdocs.org/model/bell-47g-3b-1) (registry code 1181028) (OpenAirDocs) - Registry engine: [Lycoming TVO-435-GIA](https://openairdocs.org/engine/lycoming-tvo-435-gia) (registry code 41526, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: 2812 - Airframe hours: 7481 - Engines: Lycoming TVO 435B1A 270 horsepower reciprocating - Damage: Substantial damage - Flight: Business, Part 91 - Registered owner: Clifford J. Heaverne - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 17, 2003, 19 hours before - Departed: Diamond, OR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: serious; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane, helicopter; medical: class 2, valid medical--w/ waivers/lim; last flight review June 26, 2003; seat: left; flight hours: 22,468 total, 11,280 in this make and model, 22,468 as pilot in command, 141 in the last 90 days, 60 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 10° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 54 °F, dew point 34 °F - Altimeter: 30.30 inHg - Observed at: BNO, 38 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20030912023029A](https://openairdocs.org/incident/20030912023029A), Sep 12, 2003: Bell 47G3B1, Diamond, OR, Substantial damage. (-23) While herding wild horses with his helicopter, pilot went into a hover at about 40 feet above the ground. All of a sudden the engine wound up to a high… ## Other investigations on N48020 (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB LAX03TA043](https://openairdocs.org/ntsb/LAX03TA043), Dec 1, 2002: Bell 47G-3B-1 (N48020), Panaca, NV, substantial damage. Probable cause: separation of the no. 6 cylinder intake valve head from the valve stem, which resulted in a loss of engine power. The mechanism responsible for the valve failure is unknown. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.