# NTSB ATL83FA312: Sikorsky S-58D, N6488, Gatlingurg, TN, August 6, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Field investigation · Final report
- Date: August 6, 1983, 16:10 local (20:10 UTC)
- Place: Gatlingurg, TN
- Coordinates: 35.720199, -83.489181 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.7202&lon=-83.4892&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 5941
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL83FA312
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5941/pdf
- Page: https://openairdocs.org/ntsb/ATL83FA312

## 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, takeoff - initial climb
  - fluid,fuel - contamination (cause)
  - abort - not possible, pilot in command (contributing factor)
  - fuel system,screen - blocked(partial) (cause)
  - engine assembly,cylinder - low compression (cause)
  - engine assembly,valve,intake - movement restricted (contributing factor)
- In flight collision with terrain/water, takeoff - initial climb
  - terrain condition - mountainous/hilly (contributing factor)
  - fatigue(flight schedule), pilot in command (cause)
  - object - tree(s) (contributing factor)
  - weather condition - high density altitude (contributing factor)

## Analysis

THE HELICOPTER COLLIDED WITH TERRAIN ON A WOODED MOUNTAINSIDE AFTER LIFTOFF. THE PLT SAID A POWER LOSS OCCURRED AFTER ITWAS TO LATE TO ABORT. TAKEOFF WAS MADE FROM A LOT THAT WAS 5200 FT MSL. THE PLT HOVER-CHECKED AT 2500 RPM AND 39.5 INCHES OF MANIFOLD PRESSURE PRIOR TO TRANSITION TO FORWARD FLT. THE ACFT CLIMBED ONLY 20 FT BEFORE POWERLOSS OCCURRED. THERE WERE NO CHIP LIGHTS OR UNUSUAL ENGINE GAGE READINGS. THIS WAS THE PLTS 65TH TRIP FOR THE DAY. DURING THE IMPACT THE THE RIGHT LANDING GEAR COLLAPSED. DURING THE INVESTIGATION THE COMPRESSION WAS FOUND TO BE LOW ON 4 CYLINDERS, TWO OF WHICH WERE ZERO. TSO WAS 573 HOURS. THE CARBURETOR INLET SCREEN WAS PARTIALLY BLOCKED WITH FIBER LINT. COMPRESSION WAS BEING LOST THROUGH THE EXHAUST VALVES. FUEL FILTER WERE PARTIALLY OBSTRUCTED WITH CONTAMINANTS FROM FUEL DRUMS AT A WORKSITE.

## Aircraft

- Registration: [N6488](https://openairdocs.org/deregistered/N6488-2013-02-13), registration cancelled 2013-02-13, S/N 581573, built 1964 (OpenAirDocs)
- Reported make and model: SIKORSKY S-58D
- Registry model: [Sikorsky S-58D](https://openairdocs.org/model/sikorsky-s-58d) (registry code 8141808) (OpenAirDocs)
- Registry engine: [Wright C9HE series](https://openairdocs.org/engine/wright-c9he-series) (registry code 67029, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 581573
- Airframe hours: 8247
- Engines: WRIGHT R-1820-84 1475 horsepower reciprocating
- Damage: Substantial damage
- Flight: Other work use, Part 91
- Registered owner: St. Louis Helicopters
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Unknown, April 6, 1983, 78 hours before
- Destination: 3A9, SEVIERVILLE, TN

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; commercial; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 5,430 total, 3,630 in this make and model, 5,230 as pilot in command, 141 in the last 90 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 4 statute miles
- Lowest ceiling: none
- Temperature: 61 °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 19830806039309A](https://openairdocs.org/incident/19830806039309A), Aug 6, 1983: Skrsky S58D, Gatlinburg, TN, Substantial damage. Helicopter lost power during transition from hover to forward flight and crashed into trees.

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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