# NTSB DEN82DA073: Hughes 369D (500D), N8684F, Coalville, UT, April 27, 1982

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Final report
- Date: April 27, 1982, 12:55 local (18:55 UTC)
- Place: Coalville, UT
- Coordinates: 40.879009, -111.310386 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.8790&lon=-111.3104&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report April 27, 1983
- Report: Approved by Office Director
- NTSB case key (mKey): 70293
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN82DA073
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/70293/pdf
- Page: https://openairdocs.org/ntsb/DEN82DA073

## Sequence of events

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

- Airframe/component/system failure/malfunction, maneuvering
  - rotor drive system,clutch assembly - failure,total (cause)
- Forced landing, landing - flare/touchdown
  - terrain condition - downhill (contributing factor)
  - autorotation - attempted, pilot in command (contributing factor)
- Roll over, landing - flare/touchdown

## Analysis

THE HELICOPTER MADE A HARD LANDING AFTER THE PILOT EXPERIENCED A POWER TRAIN FAILURE WHILE FLYING LOW AND SLOW. THE WEATHER WAS VMC AND A VFR FLIGHT PLAN WAS FILED. THE CREW WAS SEARCHING FOR LOST MINING EQUIPMENT IN A LOW SLOW SEARCH PATTERN. THE PILOT HEARD THE ENGINE OUT AUDIO IN HIS HEAD SET AS HE WAS LOOKING OUT. HE MANAGED TO AVOID TREES WHILE DESCENDING BUT MADE A HARD LANDING ON A STEEP SLOPE AND THE HELICOPTER ROLLED OVER.

## Aircraft

- Registration: [N8684F](https://openairdocs.org/deregistered/N8684F-1996-12-11), registration cancelled 1996-12-11, S/N 1170228D (OpenAirDocs)
- Reported make and model: HUGHES 369D (500D) (369D (500D)
- Registry model: [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d) (registry code 4470706) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1170228D
- Airframe hours: 3397
- Engines: ALLISON 250C20B 420 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Part 91
- Operator: Rocky Mountain Helicopters Inc
- Registered owner: Gatx Second Aircraft Corp.
- Departed: HENEFER, UT
- Destination: HENEFER, UT
- Flight plan: Unknown

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 32; commercial; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; flight hours: 4,050 total, 2,010 in this make and model, 3,898 as pilot in command, 150 in the last 90 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 225° at 6 knots
- Visibility: 15 statute miles
- Temperature: 122 °F
- Altimeter: 29.00 inHg

## 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 19820427011929A](https://openairdocs.org/incident/19820427011929A), Apr 27, 1982: Hughes 369D, Coalville, UT, Substantial damage. Helicopter crashed when overrunning clutch failed during low level operation.

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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