# NTSB DEN92FA034: Bell 206L-3, N99TV, Fort Collins, CO, February 12, 1992

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: February 12, 1992, 11:40 local (18:40 UTC)
- Place: Fort Collins, CO
- Coordinates: 40.520141, -105.140281 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.5201&lon=-105.1403&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal, 1 serious
- Status: Completed, report May 3, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 18146
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN92FA034
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/18146/pdf
- Page: https://openairdocs.org/ntsb/DEN92FA034

## 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.

## Analysis

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.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power(total) - mech failure/malf, cruise
  - maintenance,overhaul,major - improper, other maintenance personnel (contributing factor)
  - lubricating system,oil port/passage,internal - blocked(partial) (cause)
  - fluid,oil - starvation (cause)
  - engine assembly,bearing - failure,total (cause)
- Forced landing, descent - emergency
  - autorotation - performed, pilot in command
- Ditching, landing
  - weather condition - fog (contributing factor)
  - terrain condition - none suitable (contributing factor)
  - terrain condition - water (contributing factor)
  - terrain condition - water,frozen (contributing factor)

## Aircraft

- Registration: N99TV (not matched to a registry record)
- Reported make and model: BELL 206L-3
- Category: Helicopter
- Serial number: 51280
- Airframe hours: 1295
- Engines: ALLISON 250-C30P 650 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Ferry, Part 91
- Operator: Kusa Television, doing business as Channel 9
- Registered owner: Kusa Television
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, January 27, 1992, 9 hours before
- Departed: DEN, DENVER, CO
- Destination: 3V5, FORT COLLINS, CO

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 47; commercial; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 10,000 total, 2,500 in this make and model, 9,500 as pilot in command, 40 in the last 90 days, 5 in the last 30 days

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 170° at 8 knots
- Temperature: 34 °F, dew point -0 °F

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19920212046059A](https://openairdocs.org/incident/19920212046059A), Feb 12, 1992: Bell 206L3, Fort Collins, CO, Substantial damage, 2 fatal. Lost power while flying low over lake in IMC. Ditched in icy water. Bearing oil tube fouled by cleaner in overhaul.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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