# NTSB FTW87FA156: Aerospatiale AS-355-F1, N5796M, Venice, LA, July 4, 1987

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: July 4, 1987, 14:45 local (19:45 UTC)
- Place: Venice, LA
- Coordinates: 29.269462, -89.350456 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=29.2695&lon=-89.3505&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report May 16, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 22256
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW87FA156
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/22256/pdf
- Page: https://openairdocs.org/ntsb/FTW87FA156

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise - normal
  - rotor system,rotor vibration absorber - not secured (cause)
  - rotor system,rotor vibration absorber - loose (cause)
  - maintenance,installation - improper, company maintenance personnel (cause)
  - maintenance,inspection - inadequate, company maintenance personnel (cause)
- Loss of control - in flight, cruise - normal
  - rotor system,rotor vibration absorber - separation (cause)
  - aircraft control - not possible
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - water

## Analysis

ONE OF THE MECHANICS WHO PERFORMED MAINTENANCE ON THE AIRCRAFT MAIN ROTOR HEAD STATED THAT HE WAS NOT SURE THAT HE INSTALLED THE RETAINING BOLTS WHICH SECURED THE VIBRATION ABSORBER ASSEMBLY TO THE AIRCRAFT. METALLURGICAL ANALYSIS OF THE ASSEMBLY INDICATED THAT THE RETAINING BOLTS WERE NOT INSTALLED AT IMPACT. EXAMINATION OF THE WRECKAGE SUGGESTS THAT THE VIBRATION ABSORBER ASSEMBLY SEPARATED FROM THE AIRCRAFT AND CONTACTED THE MAIN ROTOR SYSTEM RESULTING IN LOSS OF AIRCRAFT CONTROL AND SUBSEQUENT CONTACT WITH THE TERRAIN (WATER). WITNESSES OBSERVED THE HELICOPTER COME APART IN FLIGHT AFTER HEARING A LOUD 'BOOM'.

## Aircraft

- Registration: N5796M (not matched to a registry record)
- Reported make and model: AEROSPATIALE AS-355-F1
- Category: Helicopter
- Serial number: 5162
- Airframe hours: 4460
- Engines: ALLISON 250-C20F 420 horsepower turbo shaft
- Damage: Destroyed
- Flight: Part 135
- Operator: Petroleum Helicopters,Inc.
- Registered owner: Petroleum Helicopters Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, July 3, 1987, 4 hours before
- Departed: 7R1, VENICE, LA
- Destination: GULF OF MEXICO
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; commercial; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: right; toxicology performed; flight hours: 5,739 total, 543 in this make and model, 4,819 as pilot in command, 202 in the last 90 days, 9 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 12 knots
- Visibility: 10 statute miles
- Lowest ceiling: 1,700 ft broken
- Temperature: 91 °F, dew point 75 °F
- Altimeter: 30.00 inHg
- Observed at: 7R1, 17 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 19870704032409A](https://openairdocs.org/incident/19870704032409A), Jul 4, 1987: Aerosp AS355F1, Venice, LA, Destroyed, 1 fatal. Main rotor head and blades separated in flight. Vibration absorber assembly bolts not installed during maintenance.

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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