ANC08LA083 · Bell UH-1B
Pollux Avaition Bell UH-1B · Accident: flight control system malfunction/failure during autorotation
From PLATINUM, AK to Iliamna Airport (ILI)
Narrative check · The NTSB narrative appears to contradict this record's location. Values are shown as recorded, not corrected; compare with the narrative.
Event
- NTSB case
- ANC08LA083
- 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 UH-1B
- Aircraft type
- Bell UH-1
- 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
- N64RA
- Operator
- Pollux Avaition
- Onboard fatalities
- Unknown
- Route
- From PLATINUM, AKTo Iliamna Airport (ILI), ILIAMNA, AK
- 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
- Autorotation
- Defining eventThe 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
- Flight control system malfunction/failure
- 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
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The commercial pilot said that as the helicopter approached the destination airport during a Part 91 repositioning flight, he elected to make a practice autorotation to the runway. As he lowered the collective to enter the autorotation, the helicopter began to vibrate violently. He continued the autorotation to runway, and stated that during the landing flare the helicopter's tail boom contacted the runway, the helicopter rocked forward, and the landing gear skids struck the ground. The hard landing resulted in substantial damage to the fuselage, tail boom assembly, and main rotor transmission supports. A maintenance technician that did a postaccident inspection of the helicopter discovered loose and worn bearings on the helicopter's stabilizer bar, swashplate, flight control tube assemblies, and the right and left hydraulic servos. In a written report the maintenance technician reported that the mechanical discrepancies he discovered during his inspection were, in part: "noted as being the root cause of the vertical vibration..."
Probable cause
The failure of company maintenance personnel to ensure the helicopter was properly maintained, resulting in a severe in-flight vibration due to collective bounce. Contributing to the accident was loose and worn bearings on the helicopter's stabilizer bar, swashplate, flight control tube assemblies, and the right and left hydraulic servos.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC08LA083
- Event ID
- 20080709X01001
- Case number
- ANC08LA083
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2008-06-30.
- API snapshot SHA-256: d3591a03ecde10db0f3dc105f5068bb5ba3eb259548982e3eb782a379276ac69; retrieved 2026-09-15T09:52:48.003Z.