# NTSB CHI84LA279: Bell 47G2, Detroit, MI, July 4, 1984

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: July 4, 1984, 16:15 local (20:15 UTC)
- Place: Detroit, MI
- Coordinates: 42.329463, -83.050224 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.3295&lon=-83.0502&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 3 serious
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 12685
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI84LA279
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/12685/pdf
- Page: https://openairdocs.org/ntsb/CHI84LA279

## Sequence of events

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

- Loss of engine power(partial) - nonmechanical, maneuvering
  - ignition system,spark plug - corroded (cause)
  - ignition system,spark plug - worn (cause)
  - throttle/power control - reduced, pilot in command (contributing factor)
  - , pilot in command (contributing factor)
  - panic, pilot in command (contributing factor)
- Forced landing, descent - emergency
  - autorotation - attempted, pilot in command
  - adequate rotor rpm - not maintained, pilot in command (cause)
  - throttle/power control - improper use of, pilot in command (cause)
- In flight collision with terrain/water, landing - flare/touchdown
  - terrain condition - water,rough (contributing factor)
  - landing gear,float assembly - burst (contributing factor)

## Analysis

THE ACFT LANDED IN THE DETROIT RIVER AFTER THE ENGINE SPUTTERED AND THE ACFT VIBRATED. THE PLT REDUCED PWR & COLLECTIVE AND PUSHED THE CYCLIC FORWARD. THE RPM REDUCED FROM 3000 TO 2500 BUT THE ROTOR AND ENGINE RPM REMAINED MARRIED. THE PLT ADJUSTED DESCENT WITH COLLECTIVE, FORWARD SPEED WITH CYCLIC AND PULLED ALL COLLECTIVE JUST PRIOR TO IMPACT. THE ACFT WAS AT ABOUT 150 FT AGL WHEN THE ENGINE SPUTTERED. ONE PASSENGER DESCRIBED A SPUTTERING NOISE BUT SAID THE ENGINE WAS RUNNING UNTIL IMPACT. ANOTHER PASSENGER DESCRIBED THE ENGINE NOISE AS A MUFFLED MISFIRING SOUND. THE PASSENGERS ALSOSAID THE PLT DID NOT MENTION THE PROBLEM TO THEM AND THE HELICOPTER SEEMED UNDER CONTROL UNTIL IMPACT. POST ACCIDENT EXAMINATION OF THE ENGINE AFTER RECOVERY FROM THE WATER SHOWED THAT THE SPARK PLUGS WERE WORN AND CONTAINED A HEAVY BUILD-UP OF CARBON AND LEAD. NEAR THE OPERATORS HANGER WERE 5 SEALED AND 1 UNSEALED FUEL DRUMS WITH STANDING WATER ON THE TOPS. NO OTHER EVIDENCE WAS FOUND TO INDICATE ANY MALFUNCTION OF THE ACFT.

## Aircraft

- Registration: CFISH (not matched to a registry record)
- Reported make and model: BELL 47G2
- Category: Helicopter
- Serial number: 1522
- Airframe hours: 11482
- Engines: LYCOMING VO-435-A1E 240 horsepower reciprocating
- Damage: Destroyed
- Flight: Business, Part 91
- Registered owner: Arrow Smith Limited
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, May 17, 1984, 59 hours before
- Airport: DET, Detroit City

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 24; commercial; medical: class 1, valid medical--no waivers/lim.; flight hours: 218 total, 218 in this make and model, 147 as pilot in command, 122 in the last 90 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 170° at 12 knots
- Visibility: 5 statute miles
- Lowest ceiling: 4,000 ft broken
- Temperature: 84 °F, dew point 68 °F
- Altimeter: 29.00 inHg
- Observed at: DET, 6 nm away

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.