# NTSB FTW91LA098: Sikorsky S76A, N5418N, Ship Shoal 290k, June 17, 1991

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: June 17, 1991, 07:00 local (12:00 UTC)
- Place: Ship Shoal 290k
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 10 serious
- Status: Completed, report July 13, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 23345
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW91LA098
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23345/pdf
- Page: https://openairdocs.org/ntsb/FTW91LA098

## Probable cause

THE COPILOT'S REDUCTION OF POWER TO GROUND IDLE ON BOTH ENGINES.  FACTORS WERE THE PILOT'S POOR LANDING TECHNIQUE AND HIS FAILURE TO ESTABLISH ADEQUATE CREW COORDINATION.

## Sequence of events

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

- In flight collision with object, landing - aborted
  - aborted landing - performed, pilot in command
  - lift-off - improper, pilot in command (contributing factor)
  - powerplant controls - improper use of, copilot/second pilot (cause)
  - crew/group coordination - inadequate, pilot in command (contributing factor)
  - object - airport facility
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - water

## Analysis

DURING A LANDING AT AN OFF SHORE OIL RIG THE PILOT IN COMMAND (PIC) ALLOWED THE HELICOPTER TO DRIFT AND PLACED THE RIGHT MAIN GEAR OFF THE PLATFORM ONTO THE SAFETY APRON. THE PIC UNSUCCESSFULLY ATTEMPTED TWO REPOSITIONING MANEUVERS AND THEN DECIDED TO TAKEOFF AND LAND AGAIN.  DURING THE TAKEOFF FROM A HOVER THE PIC APPLIED INCREASED COLLECTIVE. THE HELICOPTER RESPONDED BY TURNING RIGHT AROUND ITS VERTICAL AXIS. THE CO-PILOT (CP) INTERPRETERED THE RIGHT TURN AS A LOSS OF DIRECTIONAL CONTROL, SO HE BROUGHT BOTH ENGINES OFF LINE BY REDUCING THE SPEED LEVERS TO GROUND IDLE. THE ACTION OF THE CP WAS TAKEN WITHOUT COORDINATION OR ANNOUNCEMENT TO HIS PIC. THE MAIN ROTOR BLADES STRUCK THE PLATFORM AND THE HELICOPTER DESCENDED UNCONTROLLED TO THE WATER. NO MECHANICAL MALFUNCTIONS WERE DISCOVERED.

## Aircraft

- Registration: [N5418N](https://openairdocs.org/deregistered/N5418N-1991-12-03), registration cancelled 1991-12-03, S/N 760209 (OpenAirDocs)
- Reported make and model: SIKORSKY S76A
- Registry model: [Sikorsky S-76A](https://openairdocs.org/model/sikorsky-s-76a) (registry code 8143006) (OpenAirDocs)
- Category: Helicopter
- Serial number: 760209
- Engines: ALLISON 250-C30E 650 horsepower turbo shaft
- Damage: Destroyed
- Flight: Part 135
- Operator: Petroleum Helicopters
- Registered owner: Petroleum Helicopters
- Airworthiness certificate: Standard, Transport
- Departed: NONE, SHIP SHOAL 209A, GM
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 62; commercial, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: helicopter, airplane; medical: class 2, valid medical--w/ waivers/lim; flight hours: 16,154 total, 5,305 in this make and model, 12,377 as pilot in command, 243 in the last 90 days, 82 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: -0 °F, dew point -0 °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 19910617022219A](https://openairdocs.org/incident/19910617022219A), Jun 17, 1991: Skrsky S76A, Ship Shoal 209k, LA, Destroyed. Rotated right on takeoff from hover. SIC pulled engine speed levers. Impacted water.

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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