# NTSB MIA83LA199: Bell 206B, N51DC, Stuart, FL, August 4, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 4, 1983, 19:45 local (23:45 UTC)
- Place: Stuart, FL
- Location: 27.1953° N, 80.2437° W: Placed by OpenAirDocs: center of Stuart, FL, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=27.1953&lon=-80.2437&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 30925
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA83LA199
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/30925/pdf
- Page: https://openairdocs.org/ntsb/MIA83LA199

## 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 - normal
  - turbine assembly,shaft - corroded (cause)
  - turbine assembly,shaft - failure,total (cause)
  - turbine assembly,turbine wheel - overspeed (contributing factor)
  - turbine assembly,turbine wheel - failure,total (contributing factor)
- Forced landing, landing - flare/touchdown
  - autorotation - performed, pilot in command

## Analysis

WHILE IN CRUISE FLT AT APRX 600 FT AGL, A CATASTROPHIC FAILURE OF THE ENGINE'S 3RD STAGE TURBINE OCCURRED. THE PLT RELATED THAT HE OBSERVED AN ENGINE CHIP DETECTOR LIGHT, WHICH WAS FOLLOWED ALMOST IMMEDIATELY BY FIRE IN THE ENGINE. HE MADE A SUCCESSFUL AUTOROTATIVE LANDING. THE FIRE WAS EXTINGUISHED BY USE OF HAND FIRE FIGHTING EQUIPMENT. FIRE DAMAGE WAS LIMITED TO THE ENGINE AREA. THE ENGINE WAS SHIPPED TO THE MANUFACTURER'S FACILITY FOR EXAMINATION. ACCORDING TO THEIR REPORT, THE FAILURE OCCURRED DUE TO WHAT APPEARED TO BE AN OIL TYPE CORROSION FROM THE I.D. SURFACE OF THE INNER POWER TURBINE SHAFT; CORROSION WEAKENED THE SHAFT BY REDUCING THE WALL THICKNESS WHICH RESULTED IN IT FRACTURING & ALLOWING THE 3RD STAGE TURBINE WHEEL TO SEPARATE FROM THE 4TH STAGE TURBINE SHEEL & OVERSPEED; THE 3RD STAGE WHEEL THEN EXPERIENCED AN UNCONTAINED BURST FAILURE AS A RESULT OF THE OVERSPEED.

## Aircraft

- Registration: [N51DC](https://openairdocs.org/deregistered/N51DC-2013-06-07), registration cancelled 2013-06-07, S/N 2732 (OpenAirDocs)
- Reported make and model: BELL 206B
- Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs)
- Category: Helicopter
- Serial number: 2732
- Airframe hours: 6329
- Engines: ALLISON 250-C20B 317 horsepower turbo shaft
- Damage: Substantial damage
- Fire: In-Flight
- Flight: Personal, Part 91
- Registered owner: Sundance Helicopter Svc., Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, February 4, 1983, 1 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; commercial; airplane ratings: single-engine land; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 5,820 total, 5,200 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 100° at 5 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 84 °F, dew point 73 °F
- Altimeter: 30.00 inHg
- Observed at: VRB

## 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 19830804040599A](https://openairdocs.org/incident/19830804040599A), Aug 4, 1983: Bell 206B, Stuart, FL, Substantial damage. Turbine fractured and blew up caused engine fire. Oil type corrosion from the I d surface separated turbine shaft.

## Other investigations on N51DC (1)

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.

- [NTSB MIA84FA067](https://openairdocs.org/ntsb/MIA84FA067), Jan 27, 1984: Bell 206B (N51DC), Stuart, FL, destroyed, 1 fatal

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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