SEA85LA097 · Hiller 12E
Hiller 12E · Accident: total loss of engine power (mechanical failure) en route
From an unrecorded airport to Myrtle Point, OR (no airport)
Event
- NTSB case
- SEA85LA097
- 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
- 0
- 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
Hiller 12E
- Aircraft type
- Hiller 12
- 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
- N99GM
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo Myrtle Point, OR (no airport)
- 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 137: Agricultural
- 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
- En route · cruise
- 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
- Total loss of engine power (mechanical 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
- Compressor assembly, impeller › Failure, total
- Compressor assembly, impeller › Fatigue
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
DURING A CFR 137 FLIGHT A TOTAL LOSS OF POWER OCCURRED WITH AN AUDIBLE SCREECH COMING FORM THE ENGINE AREA. AUTOROTATION WAS MADE AND THE ACFT WAS LANDED INTO A HEVILY TREED AREA WITH STEEP TERRAIN. DURING ENGINE TEAR DOWN A FRACTURED IMPELLER WAS FOUND. METALLURGICAL ANALYSIS REVEALED THAT THE FRACTURED IMPELLER WAS DUE TO PROGRESSION OF A PRE-EXISTING FATIGUE CRACK IN THE IMPELLER.
Verbatim NTSB analysis from the NTSB dataset
Sources
NTSB record SEA85LA097
- Event ID
- 20001214X36328
- Case number
- SEA85LA097
- 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. 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: e74848f7846681b884fe3b374c98444a1b0b6cceac41ecefec5f80dfcf5fb0eb; retrieved 2026-09-23T17:55:02.930Z.