# NTSB CHI85LA275: Bell 47G-3B-1, N7856S, Donaldson, MN, July 6, 1985

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 6, 1985, 08:30 local (13:30 UTC)
- Place: Donaldson, MN
- Coordinates: 48.570827, -96.889244 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.5708&lon=-96.8892&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 13129
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI85LA275
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/13129/pdf
- Page: https://openairdocs.org/ntsb/CHI85LA275

## 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, maneuvering - aerial application
  - eng assembly,blower/impeller/integral supercharger - failure,partial (cause)
- Forced landing, descent - emergency
- Hard landing, landing
  - terrain condition - soft

## Analysis

WHEN THE PLT APPLIED PWR TO LEVEL OFF WHILE ENTERING A SPRAY THE ENG DID NOT PRODUCE SUFFICIENT PWR TO STOP THE DESCENT.HE ATTEMPTED A RUN ON LANDING BUT THE UNEVEN TERRAIN CAUSED SUBSTANTIAL DAMAGE TO THE HELICOPTER. INSPECTION OF THE ENG REVEALED THE ACTUATING ROD FOR THE ACTUATOR TO THE WASTEGATE OF THE TURBOCHARGER WAS FROZEN TO THE HOUSING OF THE UNIT.

## Aircraft

- Registration: [N7856S](https://openairdocs.org/deregistered/N7856S-1986-03-04), registration cancelled 1986-03-04, S/N 6624 (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: 6624
- Airframe hours: 6431
- Engines: LYCOMING TV0-435-D1B 230 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Ray Larson Midwest Aviation
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, September 22, 1984, 81 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 29; private, commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 647 total, 80 in this make and model, 586 as pilot in command, 173 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 2 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 64 °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 19850706030319A](https://openairdocs.org/incident/19850706030319A), Jul 6, 1985: Bell 47G3B1, Donaldson, MN, Substantial damage. Waste gate closed, actuating rod frozen to housing. Power loss. Landed in a field, skids broke, had rotor strike.

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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