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DEN92FA034 · Bell 206L-3

12 Feb 1992 · Fort Collins, CO, United States

Bell 206L-3 · Accident: total loss of engine power (mechanical failure) en route

From Denver International Airport (DEN) to 3V5 · Fort Collins, CO

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Event

NTSB case
DEN92FA034
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
2 · 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
Instrument Meteorological Cond

Bell 206L-3

Aircraft type
Bell 206
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
N99TV
Onboard fatalities
Unknown
Route
From Denver International Airport (DEN), Denver, COTo 3V5 · Fort Collins, CO
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
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

  • Engine assembly, bearing › Failure, total
  • Fluid, oil › Starvation
  • Lubricating system, oil port/passage, internal › Blocked(partial)

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

THE HELICOPTER WAS BEING FLOWN TO A MAINTENANCE FACILITY TO CORRECT A 'ROTOR VIBRATION' THAT HAD BEEN DETECTED BY THE PILOT. WHILE IN CRUISE FLIGHT OVER A RESERVOIR, A LOSS OF ENGINE POWER OCCURRED, WHEN THE #2-1/2 BEARING FAILED DUE TO OIL STARVATION. THE OIL STARVATION RESULTED FROM AN OBSTRUCTION IN THE BEARING OIL FEED TUBE BY A PARTICLE OF FOREIGN MATERIAL. THERE WAS EVIDENCE THE MATERIAL WAS INTRODUCED INTO THE SYSTEM DURING OVERHAUL, ABOUT 9 FLIGHT HOURS BEFORE THE ACCIDENT. THE PILOT MADE AN AUTOROTATION THROUGH DENSE FOG TO THE SURFACE OF THE RESERVOIR, WHICH CONTAINED PATCHES OF ICE. THE HELICOPTER SANK IN 190 FT OF WATER. WATER TEMPERATURE WAS 30 DEG F, AIR TEMPERATURE WAS 34 DEG, AND WIND WAS 170 DEG AT 8 KTS. ACCORDING TO AVAILABLE INFORMATION, USEFUL CONSCIOUS TIME UNDER THESE CONDITIONS WOULD HAVE BEEN ABOUT 15 MIN. THE FIRST RESCUE PERSONNEL REACHED THE PILOT APPROXIMATELY 45 MIN FOLLOWING THE ACCIDENT. THE PILOT WAS THE ONLY PERSON ON THE SURFACE AT THAT TIME.

Probable cause

FAILURE OF THE NUMBER 2-1/2 BEARING DUE TO AN OBSTRUCTION OF A BEARING OIL FEED TUBE BY FOREIGN MATERIAL. FACTORS RELATED TO THE ACCIDENT WERE: IMPROPER MAINTENANCE DURING ENGINE OVERHAUL, AND WEATHER/TERRAIN/WATER CONDITIONS IN THE EMERGENCY LANDING AREA.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record DEN92FA034
Event ID
20001211X14096
Case number
DEN92FA034
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: dad4a947f9b800c348d420ba91b38ee9b4ec656cf0069c8fcded3f6250448190; retrieved 2026-09-21T01:22:16.925Z.