# NTSB MIA85FA012: Hughes 369D, N8631F, St.Thomas, October 19, 1984

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: October 19, 1984, 10:59 local (14:59 UTC)
- Place: St.Thomas
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 3 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 31205
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA85FA012
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/31205/pdf
- Page: https://openairdocs.org/ntsb/MIA85FA012

## Sequence of events

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

- Loss of engine power, maneuvering
  - engine assembly - undetermined (cause)
  - altitude - inadequate, pilot in command (cause)
  - overconfidence in personal ability, pilot in command (contributing factor)
  - airspeed - inadequate, pilot in command (cause)
  - autorotation - not possible, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - water,rough

## Analysis

THE ACFT WAS FLYING AT 50 FEET ABOVE THE WATER AT 15 KNOTS AIRSPEED PHOTOGRAPHING A SAIL BOAT. THE ACFT THEN CLIMBED TO 150 FEET AND DRIFTED LEFT OVER THE TOP OF THE BOAT. AT THIS POINT WITNESSES REPORTED HEARING A LOUD POP AND SEEING A PUFF OF BLACK SMOKE COME FROM THE ENGINE EXHAUST. ENGINE NOISE CEASED AND THE ACFT ROLLED APPROX 90 DEGREES ONTO ITS LEFT SIDE AND DESCENDED INTO THE WATER. POST CRASH INSPECTION OF THE ACFT REVEALED NO EVIDENCE OF PRECRASH MECHANICAL FAILURE OR MALFUNCTION OF THE STRUCTURE, ROTOR HEAD, ROTOR BLADES, OR MAIN ROTOR GEAR BOX. INSPECTION OF THE ENGINE AND ENGINE COMPONENTS REVEALED NO EVIDENCE TO INDICATE PRECRASH MECHANICAL FAILURE OR MALFUNCTION. WITNESSES REPORTED THEY SAW NO COMPONENTS FALL FROM THE AIRCRAFT PRIOR TO THE CRASH.

## Aircraft

- Registration: [N8631F](https://openairdocs.org/deregistered/N8631F-1988-05-14), registration cancelled 1988-05-14, S/N 770158D (OpenAirDocs)
- Reported make and model: HUGHES 369D
- Registry model: [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d) (registry code 4470706) (OpenAirDocs)
- Category: Helicopter
- Serial number: 770158D
- Airframe hours: 1325
- Engines: ALLISON 250-C20B 375 horsepower turbo shaft
- Damage: Destroyed
- Flight: Business, Part 91
- Operator: Whirlwind Helicopters, doing business as 25a Dronnings Gade Rd.
- Registered owner: Arjay Aviation Services, Ltd
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, September 20, 1984, 13 hours before
- Departed: ST.THOMAS

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; commercial; airplane ratings: single-engine land; medical: class 1, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 4,000 total, 25 in the last 90 days, 25 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 90° at 10 knots
- Visibility: 40 statute miles
- Lowest ceiling: none
- Temperature: 86 °F, dew point 73 °F
- Altimeter: 30.00 inHg
- Observed at: STT, 10 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 19841019057359A](https://openairdocs.org/incident/19841019057359A), Oct 19, 1984: Hughes 369D, St Thomas, U.S. Virgin Islands, Destroyed, 2 fatal. Loud pop and sizzle heard. Aircraft rolled onto side and impacted water from 150 feet. Too low for autorotation.

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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