# NTSB MIA82DA125: Bell 47J-2A, N73268, Marathon, FL, May 29, 1982

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: May 29, 1982, 18:45 local (22:45 UTC)
- Place: Marathon, FL
- Coordinates: 24.70984, -81.079772 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=24.7098&lon=-81.0798&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report May 29, 1983
- Report: Approved by Office Director
- NTSB case key (mKey): 71572
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA82DA125
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/71572/pdf
- Page: https://openairdocs.org/ntsb/MIA82DA125

## Sequence of events

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

- Roll over, takeoff
  - terrain condition (contributing factor)
  - aircraft preflight - inadequate, pilot in command (cause)

## Analysis

THE PILOT REPORTED THAT AN INTERMITTENT VIBRATION WAS FELT DURING THE MAGNETO CHECK BEFORE TAKEOFF. DURING A SECOND MAGNETO CHECK AT HIGH POWER, THE NOSE OF THE HELICOPTER CAME UP, A LOUD EXPLOSIVE NOISE WAS HEARD, AND A FIRE ERUPTED NEAR THE LEFT FUEL TANK. THE PILOT AND PASSENGER ABANDONED THE HELICOPTER UNINJURED, BUT IT WAS DESTROYED. THIS WAS THE FIRST FLIGHT AFTER MAINTENANCE HAD BEEN COMPLETED. HOWEVER, AN EXAMINATION OF THE WRECKAGE REVEALED NO PREIMPACT FAILURES. A WITNESS STATED THAT WHEN THE PILOT ATTEMPTED TO TAKEOFF, THE REAR END OF THE RIGHT SKID CAUGHT UNDER A BOARDWALK, THE HELICOPTER ROLLED OR BANKED, AND THE MAIN ROTOR STRUCK THE TAIL BOOM.

## Aircraft

- Registration: [N73268](https://openairdocs.org/deregistered/N73268-2014-11-17), registration cancelled 2014-11-17, S/N 1871, built 1962 (OpenAirDocs)
- Reported make and model: BELL 47J-2A
- Registry model: [Bell 47J-2A](https://openairdocs.org/model/bell-47j-2a) (registry code 1181106) (OpenAirDocs)
- Registry engine: [Lycoming VO-540 series](https://openairdocs.org/engine/lycoming-vo-540-series) (registry code 41534, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1871
- Airframe hours: 3181
- Engines: LYCOMING VO-540 240 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Operator: Alex Butchkosky
- Registered owner: Dingman Allison
- Departed: MTH, MARATHON, FL
- Destination: MTH, MARATHON, FL
- Airport: MTH, Marathon

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 51; commercial; medical: class 3, valid medical--no waivers/lim.; flight hours: 1,613 total, 270 in this make and model, 37 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 150° at 8 knots
- Visibility: 10 statute miles
- Lowest ceiling: 25,000 ft overcast
- Temperature: 185 °F
- Altimeter: 29.00 inHg
- Observed at: EYWW, 40 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 19820529042539A](https://openairdocs.org/incident/19820529042539A), May 29, 1982: Bell 47J2A, Marathon, FL, Destroyed. Rear of skid caught under boardwalk on attempted takeoff. Helicopter crashed and turned. Pilots story differs.

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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