# NTSB DEN82FTM11: Bell 47G-3B-1, N48217, Vermal, UT, April 28, 1982

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Final report
- Date: April 28, 1982, 10:00 local (17:00 UTC)
- Place: Vermal, UT
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 3 serious
- Status: Completed, report April 28, 1983
- Report: Approved by Office Director
- NTSB case key (mKey): 72922
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN82FTM11
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/72922/pdf
- Page: https://openairdocs.org/ntsb/DEN82FTM11

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, approach
  - weather condition - high density altitude (contributing factor)
  - ignition system,low tension wiring - disconnected (cause)
  - ignition system,magneto - inoperative (cause)
- In flight collision with terrain/water, landing
  - terrain condition - high terrain (contributing factor)

## Analysis

THE PILOT STATED THAT HE EXPERIENCED A PARTIAL LOSS OF ENGINE POWER DURING LANDING AT AN ELEVATION OF ABOUT 5280 FT MSL. THE TEMPERATURE WAS ABOUT 50 DEGREES FAHRENHEIT. HE APPLIED FULL THROTTLE, BUT THE RPM DECAYED AND THE PLANE CRASH LANDED. A PARTIAL ENGINE TEARDOWN REVEALED THAT THE GROUNDING WIRE ON THE RIGHT MAGNETO WAS DISCONNECTED. ON THIS MAGNETO, A BENDIX S-200, THE DISCONNECTED WIRE WOULD CAUSE THE MAGNETO TO GROUND OUT AND CEASE FUNCTIONING. WITH ONE MAGNETO GROUNDED, THERE WOULD BE A LOSS OF ABOUT 200 RPM.

## Aircraft

- Registration: [N48217](https://openairdocs.org/aircraft/N48217), registered now, S/N 2760 (OpenAirDocs)
- Reported make and model: BELL 47G-3B-1
- Registry model: [Bell 47G-3B-1](https://openairdocs.org/model/bell-47g-3b-1) (registry code 1181028) (OpenAirDocs)
- Category: Helicopter
- Serial number: 2760
- Airframe hours: 6044
- Engines: LYCOMING TVO-435 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 137
- Operator: Intermountain Survey
- Registered owner: Intermountain Survey
- Departed: SLC, VERMAL, UT
- Destination: SLC, VERMAL, UT
- Airport: SLC, Vermal

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; airline transport, commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; flight hours: 4,983 total, 4 in this make and model, 22 in the last 90 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 50 statute miles
- Temperature: 122 °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 19820428012369A](https://openairdocs.org/incident/19820428012369A), Apr 28, 1982: Bell 47G3B1, Vernal, UT, Substantial damage. During approach for landing helicopter crashed when partial power failure occurred.

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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