# NTSB FTW85LA295: Bell 206L-1, N5753D, South Marsh, July 21, 1985

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: July 21, 1985, 17:00 local (22:00 UTC)
- Place: South Marsh
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 21807
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW85LA295
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/21807/pdf
- Page: https://openairdocs.org/ntsb/FTW85LA295

## Sequence of events

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

- Airframe/component/system failure/malfunction, takeoff
  - rotorcraft flight control,tail rotor control - undetermined (cause)
- Forced landing, descent - emergency
- Ditching, landing - flare/touchdown
  - terrain condition - water,rough

## Analysis

THE PLT WAS INITIATING A TAKEOFF FROM A HOVER OFF AN OFFSHORE OIL RIG. AS HE LOWERED THE NOSE FOR TAKEOFF, HE HEARD A LOUD NOISE EMIT FROM THE TAILBOOM AREA & THE ACFT BEGAN ROTATING TO THE RIGHT. THE PLT CONTINUED TO APPLY PWR AND AUTOROTATED TO THE WATER. ON IMPACT, THE MAIN ROTOR STRUCK THE TAILBOOM AND SEVERED IT. THE AFT SECTION OF THE TAILBOOM AND THE TAIL ROTOR GEARBOX WERE NOT RECOVERED. INDICATIONS ARE THAT THE ACFT EXPERIENCED A MALFUNCTION IN THE TAIL ROTOR DRIVE SYSTEM.

## Aircraft

- Registration: [N5753D](https://openairdocs.org/deregistered/N5753D-1997-11-21), registration cancelled 1997-11-21, S/N 45529 (OpenAirDocs)
- Reported make and model: BELL 206L-1
- Registry model: [Bell Helicopter Textron 206L-1](https://openairdocs.org/model/bell-helicopter-textron-206l-1) (registry code 1182107) (OpenAirDocs)
- Category: Helicopter
- Serial number: 45529
- Airframe hours: 6941
- Engines: ALLISON 250-C28 435 horsepower turbo shaft
- Damage: Destroyed
- Flight: Part 135
- Registered owner: Petroleum Helicopters,Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, July 7, 1985, 75 hours before
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 44; airline transport; instrument ratings: helicopter; medical: valid medical--w/ waivers/lim; seat: right; flight hours: 4,107 total, 1,707 in this make and model, 3,354 as pilot in command, 228 in the last 90 days, 12 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 290° at 8 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 88 °F, dew point 72 °F
- Altimeter: 29.00 inHg
- Observed at: 1700, 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 19850721033189A](https://openairdocs.org/incident/19850721033189A), Jul 21, 1985: Bell 206L1, Gulf Of Mexico, LA, Destroyed. During takeoff from south March block 57 platform, tail rotor system failed. Landed in water. Tail boom not found.

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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