# NTSB CHI84LA184: Bell 47D1, N9158R, Alpena, MI, May 20, 1984

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: May 20, 1984, 17:20 local (21:20 UTC)
- Place: Alpena, MI
- Coordinates: 45.069091, -83.429504 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=45.0691&lon=-83.4295&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 12606
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI84LA184
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/12606/pdf
- Page: https://openairdocs.org/ntsb/CHI84LA184

## Sequence of events

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

- Loss of control - in flight, maneuvering
  - maintenance,annual inspection - not performed, company/operator management
  - procedures/directives - not followed, pilot in command
  - judgment - poor, pilot in command (cause)
  - impairment(alcohol), pilot in command (cause)
  - buzzing - performed, pilot in command (contributing factor)
  - aircraft handling - not maintained, pilot in command (cause)
  - descent - uncontrolled, pilot in command
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

PRIOR TO THE ACCIDENT, THE OWNER/PLT OF THE HELICOPTER REPORTEDLY 'BUZZED' A LOCAL BASEBALL GAME. SHORTLY AFTER THAT, THE HELICOPTER WAS OBSERVED TO MANEUVER OVER A WOODED AREA, ENTER A NOSE HIGH ATTITUDE, THEN ROLL OR BANK & ENTER A DESCENT INTO A WOODED AREA & CRASH. DURING AN INSPECTION OF THE HELICOPTER, NO PREIMPACT DISCREPANCIES WERE FOUND, EXCEPT THAT THE ANNUAL INSPECTION WAS OVERDUE. A CHECK OF THE PLT'S BLOOD SHOWED AN ALCOHOL LEVEL OF 0.25%.

## Aircraft

- Registration: [N9158R](https://openairdocs.org/aircraft/N9158R), registered now, S/N 455, built 1960 (OpenAirDocs)
- Reported make and model: BELL 47D1
- Registry model: [Bell 47D1](https://openairdocs.org/model/bell-47d1) (registry code 1180802) (OpenAirDocs)
- Registry engine: [Franklin 6V4 series](https://openairdocs.org/engine/franklin-6v4-series) (registry code 27033, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 455
- Airframe hours: 23
- Engines: FRANKLIN 6V4-200 200 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Registered owner: E.L. Decker
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 17, 1979, 69 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 59; private; airplane ratings: single-engine land, multi-engine land; medical: class 3, expired; seat: right; toxicology performed; flight hours: 854 total, 227 in this make and model, 759 as pilot in command, 4 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 140° at 9 knots
- Visibility: 15 statute miles
- Lowest ceiling: 7,000 ft broken
- Temperature: 55 °F, dew point 45 °F
- Altimeter: 29.00 inHg
- Observed at: APN

## 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 19840520017799A](https://openairdocs.org/incident/19840520017799A), May 20, 1984: Bell 47D, Alpena, MI, Destroyed. Buzzed area then pulled up steeply and stalled rotors. Helicopter fell into a wooded area.

## Other investigations on N9158R (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 WPR11LA469](https://openairdocs.org/ntsb/WPR11LA469), Sep 27, 2011: Bell 47D1 (N9158R), Ahwahnee, CA, substantial damage. Probable cause: The pilot’s failure to maintain adequate main rotor rpm during the landing approach, which resulted in a loss of control.

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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