FTW89FA013 · Aerospatiale AS-355F-1
Aerospatiale AS-355F-1 · Accident: airframe, component or system failure during initial climb
From W. CAMERON 617, GM (no airport) to an unrecorded destination
Event
- NTSB case
- FTW89FA013
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 4 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Charter & commuter
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Aerospatiale AS-355F-1
- Aircraft type
- Aerospatiale AS-355
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N355EH
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From W. CAMERON 617, GM (no airport)To not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 135: Air Taxi & Commuter
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Initial climb
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Manufacturer › Acft/equip, inadequate design
- Rotor drive system, tail rotor drive shaft › Fatigue
- Rotor drive system, tail rotor drive shaft › Separation
Not plotted · Location withheld: coordinates are missing, conflicting, invalid, or have no accepted acquisition method. No substitute location has been invented.
NTSB narrative
ACFT WAS DEPARTING AN ELEVATED HELIDECK ON AN OFFSHORE PRODUCTION PLATFORM WHEN IT EXPERIENCED A COMPLETE LOSS OF TAIL ROTOR THRUST AND ACFT CONTROL DUE TO A FAILURE OF THE TAIL ROTOR DRIVE SHAFT. THE FAILURE OCCURRED AS THE PLT INITIATED HIS TAKEOFF WITH THE ACFT HAVING JUST CLEARED THE DECK AND RECOVERY WAS NOT POSSIBLE. INVESTIGATION REVEALED THAT THE DRIVE SHAFT HAD FAILED AS A RESULT OF FATIGUE CRACKING IN AN AREA OF FRETTING WHERE THE SHAFT WAS BONDED AND BOLTED TO ITS COUPLING. THIS AND PREVIOUS FAILURES IN THE SAME AREA INDICATED THAT THE SHAFT WAS UNDER DESIGNED FOR THE APPLICATION AND NORMAL OPERATING STRESSES. SHAFT WAS SUBSEQUENTLY RE-DESIGNED AND THE FLEET RETROFITTED.
Probable cause
THE LOSS OF CONTROL OF THE AIRCRAFT WHICH OCCURRED WHEN THE TAIL ROTOR DRIVE SHAFT EXPERIENCED A FATIGUE INDUCED MATERIAL FAILURE AND TAIL ROTOR THRUST WAS LOST. EVIDENCE INDICATED THAT THE SHAFT WAS UNDER DESIGNED FOR THE LOADS THAT WERE ENCOUNTERED DURING NORMAL OPERATIONS.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW89FA013
- Event ID
- 20001213X27246
- Case number
- FTW89FA013
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: efaa9267ed4a90bec1a66c99f9d88b9aae44e970ef0360bb82b8f069224b95e7; retrieved 2026-09-18T14:10:23.830Z.