WPR23LA297 · Bell OH-58A
Bell OH-58A · Accident: fuel contamination en route
From Port Falls, ID to Cavanaugh Bay Airport (66S)
Narrative check · The NTSB narrative appears to contradict this record's departure or destination. Values are shown as recorded, not corrected; compare with the narrative.
Event
- NTSB case
- WPR23LA297
- 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
- Event fatalities
- Unknown
- 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 OH-58A
- Aircraft type
- Bell OH-58
- 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
- N613SS
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route Possible conflict
- From Port Falls, IDTo Cavanaugh Bay Airport (66S), Coolin, ID
- Aircraft age
- About 52 years (built 1971)
- 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
- En route
- 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
- Fuel contamination
- 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
- Aircraft › Fluids/miscellaneous hardware
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
About 15 minutes into the flight, with the helicopter configured in a level attitude, the engine power reduced. The low-rotor alarm then sounded. In response, the pilot initiated an autorotation and performed a run-on landing in tall grass.
Postaccident examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. The engine ran as expected when placed on a test stand. The helicopter’s fuel was contaminated and had a dark/cloudy appearance with suspended particulates. The fuel samples displayed very low oxidative stability, substantial gum formation, and particulate contamination, all of which likely resulted in the engine’s loss of power.
The pilot stored fuel for the helicopter in a 180-gallon aluminum tank with a filter positioned between the tank and a rubber fueling hose. When transferring fuel from the storage tank into the helicopter, the pilot did not filter fuel remaining in the hose between uses. The use of a large storage tank may have hastened fuel oxidation and gum formation. Also, fuel sitting in the hose may have degraded the hose, allowing contaminated fuel to enter the helicopter unfiltered.
Probable cause
Fuel contamination, which resulted in a loss of engine power. The source of the contamination could not be determined.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR23LA297
- Event ID
- 20230731192764
- Case number
- WPR23LA297
- 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: investigation status, cause areas. 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: 9ef7a456036d35f0032112b7f294a9e932cc4ad508c452d37b168acf287f4244; retrieved 2026-09-16T17:56:45.497Z.