# NTSB FTW99LA077: Bell 206L-3, N6603X, West Delta 105b, February 1, 1999

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: February 1, 1999, 10:56 local (16:56 UTC)
- Place: West Delta 105b
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report April 25, 2001
- Report: Approved by Office Director
- NTSB case key (mKey): 45741
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW99LA077
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/45741/pdf
- Page: https://openairdocs.org/ntsb/FTW99LA077

## Probable cause

The pilot's failure to maintain clearance with the oil platform's windsock on final approach to landing.

## Sequence of events

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

- In flight collision with object, approach - vfr pattern - final approach
  - object - wind sock/indicator
  - clearance - not maintained, pilot in command (cause)
- Forced landing, emergency descent/landing

## Analysis

The helicopter's tail rotor made contact with the offshore platform's windsock during final approach to landing.  The pilot heard a buzzing sound followed by a right yaw.  He then executed a hovering autorotation to the platform. Inspection of the windsock support frame showed signs of tail rotor impact damage.

## Factual narrative

On February 1, 1999, at 1056 central standard time, a Bell 206L-3 helicopter, N6603X, was substantially damaged upon impact with a wind sock during final approach at the West Delta 105B offshore platform in the Gulf of Mexico.  The commercial pilot, who was the sole occupant of the helicopter, was not injured.  The helicopter was registered to and operated by Petroleum Helicopters, Inc., of Lafayette, Louisiana.  Visual meteorological conditions prevailed and a company flight plan was filed for the Title 14 CFR Part 91 positioning flight which originated from the South Pass 25 offshore platform at 0915.

The pilot was positioning the helicopter to the West Delta 105B offshore platform when, according to the pilot's written statement, he heard a "buzzing sound followed by a right yaw."  The pilot then executed a hovering autorotation to the platform.  The pilot stated that he suspected that the tail rotor blades contacted the wind sock during the approach.  The wind sock's internal frame showed evidence of a tail rotor blade strike.

Maintenance personnel reported that one of the tail rotor blades was missing approximately the outboard four inches.  The tail rotor gear box was torn from its mounting and the tail boom had sustained structural damage.

According to company flight records, the pilot had accumulated 3,893 hours total flight time, of which 2,517 hours were in the Bell 206L-3.

## Aircraft

- Registration: [N6603X](https://openairdocs.org/aircraft/N6603X), registered now, S/N 51412, built 1990 (OpenAirDocs)
- Reported make and model: Bell 206L-3
- Registry model: [Bell 206L-3](https://openairdocs.org/model/bell-206l-3) (registry code 1182108) (OpenAirDocs)
- Registry engine: [Allison 250-C30 series](https://openairdocs.org/engine/allison-250-c30-series) (registry code 03015, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 51412
- Airframe hours: 9971
- Engines: Allison 250-C30P 650 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Positioning, Part 91
- Registered owner: Petroleum Helicopters, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, January 10, 1999, 61 hours before
- Departed: NONE, SOUTH PASS 25, GM
- Flight plan: Company VFR
- Airport: NONE, West Delta 105b Heliport

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; commercial; airplane ratings: single-engine land; instrument ratings: helicopter, airplane; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 3,893 total, 2,517 in this make and model, 3,108 as pilot in command, 152 in the last 90 days, 49 in the last 30 days, 12 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 330° at 10 knots
- Visibility: 8 statute miles
- Lowest ceiling: 15,000 ft overcast
- Temperature: 64 °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 19990201001249A](https://openairdocs.org/incident/19990201001249A), Feb 1, 1999: Bell 206L3, Gulf Of Mexico, LA, Substantial damage. Petroleum helicopters 1990 Bell 206L-3 helicopter tail rotor struck the wind sock on landing, and the rotor sustained substantial damage. No injuries were…

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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