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ASN Wikibase Occurrence # 30510
Last updated: 26 November 2021
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Date:09-JUN-1999
Time:15:35
Type:Silhouette image of generic B412 model; specific model in this crash may look slightly different
Bell 412
Owner/operator:PHI
Registration: N3893S
MSN: 33022
Fatalities:Fatalities: 0 / Occupants: 2
Other fatalities:0
Aircraft damage: Substantial
Category:Accident
Location:near Eugene Island 313, Gulf of Mexico -   United States of America
Phase: En route
Nature:Offshore
Departure airport:Garden Bank 172
Destination airport:Morgan City, LA
Investigating agency: NTSB
Narrative:
One of the tail rotor blades separated from the helicopter during cruise flight as a result of a fatigue crack. The pilots reported hearing a 'loud bang,' and the helicopter 'immediately and violently tucked down and left then rolled inverted and [was] spinning to the right.' The flying pilot righted the helicopter, and the non-flying pilot inflated the emergency floats prior to impacting the ocean. The outboard section of one of the tail rotor blades (which one could not be determined) was found and examined. A fatigue crack initiated in the spar in an 'area of round-bottomed corrosion pits 0.001 inch deep.' The two tail rotor blades installed on the helicopter had accumulated 4,644 and 4,913 hours, respectively. The tail rotor blades are life limited at 5,000 hours.

Probable Cause: The separation of a section of the tail rotor blade, and subsequent separation of the tail rotor system, as a result of fatigue cracking due to corrosion in the tail rotor blade spar.

Sources:

NTSB: https://www.ntsb.gov/_layouts/ntsb.aviation/brief.aspx?ev_id=20001212X18996&key=1


Revision history:

Date/timeContributorUpdates
27-Sep-2008 01:00 ASN archive Added
13-Mar-2009 11:59 harro Updated
06-Nov-2013 16:30 TB Updated [Operator, Source, Narrative]
14-Dec-2017 08:27 ASN Update Bot Updated [Time, Operator, Departure airport, Destination airport, Source, Damage, Narrative]

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