ASN Wikibase Occurrence # 29983
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information.
If you feel this information is incomplete or incorrect, you can submit corrected information.
| Date: | Saturday 28 October 2000 |
| Time: | 16:37 |
| Type: |  Aérospatiale AS 350B Ecureuil |
| Owner/operator: | Private |
| Registration: | N26WW |
| MSN: | 1229 |
| Year of manufacture: | 1980 |
| Total airframe hrs: | 6734 hours |
| Fatalities: | Fatalities: 1 / Occupants: 1 |
| Aircraft damage: | Destroyed |
| Category: | Accident |
| Location: | near East Cameron 231A Offshore Oil Platform, Gulf of Mexico -
 United States of America
|
| Phase: | En route |
| Nature: | Offshore |
| Departure airport: | E. Cameron 231A, GM |
| Vermillion 200, GM | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
The helicopter departed from a helipad located on an offshore oil platform, and was 3 minutes from landing at a refueling helipad on another platform, when the pilot transmitted two distress calls indicating the helicopter was "going down." There were no witnesses to the accident; however, 9 minutes after the distress calls were heard, the helicopter was found floating inverted in 3-4 foot seas. Subsequently, the helicopter sank and was later recovered and examined. Examination of the helicopter revealed no anomalies with the airframe or flight control systems. Examination of the engine revealed that the first and second stage turbine blades were fractured due to extreme heating. One blade of the second stage tubine disk had liberated from its retention slot, and all the blade roots and retention slots of this disk exhibited permanent outboard deformation, due to a combination of centripetal forces from engine operation and excessive heat. In contrast, the blade roots and retention slots of the first stage turbine disk did not exhibit evidence of outboard deformation, most likely since they were located further away from the heat source. The rear bearing assembly (located aft of the second stage disk) was contaminated with coke. The coking suggests that oil was leaking from the engine and migrating from the rear bearing assembly. The aft side of the second stage turbine disk displayed dark stain marks in the form of streaks. A passage exists that would allow oil to flow from the rear bearing to the aft face of the second stage turbine disk. Oil that strikes the disk would flow into the hot stream of gases and auto-ignite, starting a fire. Oil migration can occur if the rear bearing scavenge and vent tubes become blocked; however, the scavenge and vent tubes were checked during the engine examination and were not found blocked.
Probable Cause: the loss of engine power due to an internal engine oil leak that started an internal engine fire and the pilot's inadequate autorotation which resulted in a hard landing. A contributing factor to the accident was the rough water condition.
Accident investigation:
 |
|
Sources:
NTSB: https://www.ntsb.gov/_layouts/ntsb.aviation/brief.aspx?ev_id=20001212X22153&key=1
FAA register: 2. FAA: http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?omni=Home-N-Number&nNumberTxt=26WW
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 27-Sep-2008 01:00 | ASN archive | Added |
| 26-Jun-2014 01:51 | Dr. John Smith | Updated [Time, Operator, Total fatalities, Total occupants, Other fatalities, Location, Country, Phase, Nature, Departure airport, Destination airport, Source, Damage, Narrative] |
| 21-Dec-2016 19:16 | ASN Update Bot | Updated [Time, Damage, Category, Investigating agency] |
| 21-Dec-2016 19:20 | ASN Update Bot | Updated [Time, Damage, Category, Investigating agency] |
| 12-Dec-2017 19:14 | ASN Update Bot | Updated [Operator, Departure airport, Destination airport, Source, Narrative] |
Corrections or additions? ... Edit this accident description
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2024 Flight Safety Foundation