# NTSB SEA84FA063: Enstrom 280C, N51715, Middleton, ID, February 29, 1984

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: February 28, 1984, 17:20 local (Feb 29, 1984, 00:20 UTC)
- Place: Middleton, ID
- Coordinates: 43.740959, -116.580604 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.7410&lon=-116.5806&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 39794
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA84FA063
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/39794/pdf
- Page: https://openairdocs.org/ntsb/SEA84FA063

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, cruise - normal
  - ignition system,magneto - loose (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - autorotation - delayed, pilot in command (cause)

## Analysis

THE ACFT COLLIDED WITH THE TERRAIN DURING A TEST FLT. WITNESSES OBSERVED THE ACFT ROTATE ABOUT 180 DEGREES ABOUT ITS VERTICAL AXIS GO NOSE LOW AND DESCEND VERTICALLY TO THE GROUND. A NOISE CHANGE DESCRIBED AS A 'SPUTTER' OR TONE CHANGE' WAS HEARD DURING THIS MANEUVER. DURING THE POST ACCIDENT INSPECTION OF THE ENGINE THE MAGNETO WAS FOUND TO BE LOOSE ENOUGH TO ROTATE THROUGH AN ARC OF ALMOST 60 DEGREES RADIALLY ABOUT ITS DRIVE SHAFT. NO OTHER DISCREPANCIES WERE FOUND EXCEPT A PUNCTURE IN THE ENGINE CASE DIRECTLY BELOW THE LOWER SWASH PLATE ASSEMBLY.

## Aircraft

- Registration: [N51715](https://openairdocs.org/deregistered/N51715-2013-04-01), registration cancelled 2013-04-01, S/N 1128, built 1978 (OpenAirDocs)
- Reported make and model: ENSTROM 280C
- Registry model: [Enstrom Helicopter 280C](https://openairdocs.org/model/enstrom-helicopter-280c) (registry code 3300505) (OpenAirDocs)
- Registry engine: [Lycoming HI0-360 series](https://openairdocs.org/engine/lycoming-hi0-360-series) (registry code 41553, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1128
- Airframe hours: 4805
- Engines: LYCOMING HI0-360-E1AD 190 horsepower reciprocating
- Damage: Destroyed
- Flight: Part 91
- Registered owner: Skywatch Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, January 15, 1982, 268 hours before
- Departed: 64U, MIDDLETON, ID

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 54; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 4,630 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: 160° at 6 knots
- Visibility: 20 statute miles
- Lowest ceiling: 20,000 ft overcast
- Temperature: 45 °F, dew point 25 °F
- Altimeter: 30.00 inHg
- Observed at: BOI, 22 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 19840228006709A](https://openairdocs.org/incident/19840228006709A), Feb 28, 1984: Enstrm 280C, Middleton, ID, Destroyed, 1 fatal. According to witnesses, helicopter was proceeding 400 ft AGL when it abruptly rotated 180 degrees and crashed.

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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