# NTSB NYC84LA055: Bell 47-G3B1, N48316, Dummerston, VT, December 18, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: December 18, 1983, 11:25 local (16:25 UTC)
- Place: Dummerston, VT
- Location: 42.9304° N, 72.5919° W: Placed by OpenAirDocs: center of Town of Dummerston, VT, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=42.9304&lon=-72.5919&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): 35482
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC84LA055
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/35482/pdf
- Page: https://openairdocs.org/ntsb/NYC84LA055

## Sequence of events

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

- In flight collision with terrain/water, maneuvering
  - autorotation - simulated, pilot in command (contributing factor)
  - airspeed - misjudged, pilot in command (cause)
  - altitude - misjudged, pilot in command (cause)
- Other gear collapsed, maneuvering
  - landing gear,skid assembly - overload

## Analysis

THE PLT INITIATED A PRACTICE AUTOROTATION FROM ABOUT 600 FT AGL. AIRSPEED WAS ABOUT 55 KTS WITH LOW M/R RPM DUE TO LOW GROSS WEIGHT. A MODERATE FLARE WAS INITIATED IN AN EFFORT TO INCREASE ROTOR RPM, REDUCING THE AIRSPEED TO 40 KTS. HOWEVER, THE APPLICATION OF COLLECTIVE FAILED TO ARREST THE DESCENT RATE & THE T/R STRUCK THE GROUND CAUSING THE HELICOPTER TO VIBRATE. WHEN THE T/R STRUCK, ABOUT 6 INCHES OF ONE TIP BROKE CAUSING MORE VIBRATION. THE PLT ATTEMPTED TOLAND THE HELICOPTER, BUT DRIVE TO THE T/R CEASED TO RESPOND, & THE HELICOPTER YAWED TO THE RIGHT. THE LEFT SKID STRUCK THE GROUND & COLLAPSED, & THE MAST ASSEMBLY WAS PROJECTED THROUGH THE CANOPY BUBBLE.

## Aircraft

- Registration: [N48316](https://openairdocs.org/aircraft/N48316), registered now, S/N 3628, built 1966 (OpenAirDocs)
- Reported make and model: BELL 47-G3B1
- Registry model: [Bell 47G-3B-1](https://openairdocs.org/model/bell-47g-3b-1) (registry code 1181028) (OpenAirDocs)
- Registry engine: [Allison 250-C18](https://openairdocs.org/engine/allison-250-c18) (registry code 03075, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 3628
- Airframe hours: 5681
- Engines: LYCOMING VO-435-A1F 280 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Scenic Rotors, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, June 8, 1983, 34 hours before
- Departed: WESTBRATTLEBORO, VT

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; flight instructor, commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 1,406 total, 679 in this make and model, 1,331 as pilot in command, 71 in the last 90 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 19 °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 19831218061529A](https://openairdocs.org/incident/19831218061529A), Dec 18, 1983: Bell 47G3B1, Dummerston, VT, Substantial damage. Tail rotor hit the ground on a practice autorotation landing. Lost lateral control. Collapsed a skid. Rolled over.

## Other investigations on N48316 (2)

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 CEN16LA182](https://openairdocs.org/ntsb/CEN16LA182), May 13, 2016: Bell 47G 3B 1 (N48316), Portia, AR, substantial damage, 1 fatal. Probable cause: The pilot's decision to perform a sliding takeoff from the elevated platform, which resulted in a dynamic rollover when the right skid plate caught on a protruding screw. Contributing to the accident…
- [NTSB NYC95LA147](https://openairdocs.org/ntsb/NYC95LA147), Jul 10, 1995: Bell 47G-3B-1 (N48316), Hammonton, NJ, destroyed, 1 fatal. Probable cause: failure of the collective yoke bearing, which resulted in an uncontrolled descent and collision with trees. A factor relating to the accident was: the manufacturer's inadequate inspection interval of…

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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