SEA03LA189 · Bell 47G-3B-1
Bell 47G-3B-1 · Accident: loss of engine power while maneuvering
From Diamond, OR to an unrecorded destination
Event
- NTSB case
- SEA03LA189
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Bell 47G-3B-1
- Aircraft type
- Bell 47
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N48020
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Diamond, ORTo not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Maneuvering · hover
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Loss of engine power
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Reason for occurrence undetermined
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
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.
Probable cause
Loss of engine power for undetermined reasons during hover.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA03LA189
- Event ID
- 20030922X01569
- Case number
- SEA03LA189
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 5cc0411062c5c7b5cacc147fe106161aa3bfb7fa599cde15b889be6ed7180634; retrieved 2026-09-21T09:22:59.880Z.