# NTSB CHI87FA139: Bell 47G, N128B, Dayton, MN, June 3, 1987

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: June 3, 1987, 10:20 local (15:20 UTC)
- Place: Dayton, MN
- Coordinates: 45.17918, -93.469436 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=45.1792&lon=-93.4694&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report February 24, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 13643
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI87FA139
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/13643/pdf
- Page: https://openairdocs.org/ntsb/CHI87FA139

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise
  - misc rotorcraft,tail boom - corroded (cause)
  - maintenance - not performed, company/operator management (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

AIRCRAFT COLLIDED WITH TERRAIN AFTER TAILBOOM STRUCTURE FAILED BECAUSE OF INTERNAL CORROSION. THE AIRCRAFT WAS NOT REGISTERED AT THE TIME OF THE ACCIDENT AND THE PILOT/OPERATOR FAILED TO ASSURE THAT PROPER OR TIMELY PREVENTIVE MAINTENANCE WAS PERFORMED ON THE AIRCRAFT.

## Aircraft

- Registration: [N128B](https://openairdocs.org/deregistered/N128B-2003-08-19), registration cancelled 2003-08-19, S/N 48, built 1947 (OpenAirDocs)
- Reported make and model: BELL 47G
- Registry model: [Bell 47B](https://openairdocs.org/model/bell-47b) (registry code 1180604) (OpenAirDocs)
- Registry engine: [Franklin 6V 350 series](https://openairdocs.org/engine/franklin-6v-350-series) (registry code 27043, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 48
- Engines: FRANKLIN 6V-350-A 235 horsepower reciprocating
- Damage: Destroyed
- Flight: Business, Part 91
- Operator: Rand Auto Body, doing business as Classic Helicopters, Inc.
- Registered owner: Rand Auto Body
- Airworthiness certificate: Standard, Normal
- Departed: ANE, ANOKA, MN

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; private, commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 4,050 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: 320° at 15 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Altimeter: 30.00 inHg
- Observed at: MIC, 13 nm away

## 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 19870603018319A](https://openairdocs.org/incident/19870603018319A), Jun 3, 1987: Bell 47G, Dayton, MN, Destroyed, 2 fatal. Inflight separation of tailboom from fuselage resulted in uncontrolled descent and impact. Corroded tubing failed.

## Other investigations on N128B (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 MKC78DTK29](https://openairdocs.org/ntsb/MKC78DTK29), Jul 29, 1978: Bell 47G (N128B), Elk Point, SD, substantial damage

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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