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2005-11-01: Free Turbine Overspeed Protection System

FAA order 2005-11-01 is an airworthiness directive in force since June 13, 2005. The FAA's subject line: Free Turbine Overspeed Protection System. It names the Turbomeca (Safran) ARRIUS 1A engine: about 5 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: engine.

What it applies to as the FAA lists it

Kind of product
Engine
Makes
Turbomeca S.A.
Models
Arrius 1A
Engine series
Turbomeca (Safran) ARRIUS 1A 5 aircraft

Dates and paperwork

In force since
June 13, 2005
Published
May 27, 2005 (signed May 17, 2005)
Docket
FAA-2005-21273
Status
Current
The FAA's document
Read the order on the FAA's site

The FAA's summary their words, unchanged

The FAA is adopting a new airworthiness directive (AD) for Turbomeca S.A. Arrius 1A turboshaft engines. This AD requires initial and repetitive testing of the Free Turbine Overspeed Protection System. This AD results from an investigation into the Digital Electronic Control Unit (DECU) that revealed a malfunction of the Free Turbine Overspeed Protection System. This malfunction can exist despite the DECU passing all functional tests specified in the Engine Maintenance Manual. We are issuing this AD to prevent uncontained engine failure if a free turbine overspeed occurs.

The order itself the regulatory text, as published

Show the full text (3,204 characters)
2005-11-01 Turbomeca S.A.: Amendment 39-14103. Docket No. FAA-2005- 21273; Directorate Identifier 2005-NE-15-AD. Effective Date (a) This airworthiness directive (AD) becomes effective June 13, 2005. Affected ADs (b) None. Applicability (c) This AD applies to Turbomeca S.A. Arrius 1A turboshaft engines. These engines are installed on, but not limited to, Eurocopter AS355N Twinstar helicopters. Unsafe Condition (d) This AD results from an investigation into the Digital Electronic Control Unit (DECU) that revealed a malfunction of the Free Turbine Overspeed Protection System can exist despite the DECU passing all functional tests specified in the Engine Maintenance Manual. We are issuing this AD to prevent uncontained engine failure in the event of a free turbine overspeed. Compliance (e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.Initial Testing (f) Within 25 flight hours after the effective date of this AD, test the DECU Free Turbine Overspeed Protection System, using paragraph 2.B. of the Instructions to be Incorporated of Turbomeca Alert Mandatory Service Bulletin No. A319 77 0804, dated March 24, 2005. (g) If the DECU Free Turbine Overspeed Protection System fails the test specified in paragraph (f) of this AD, replace the DECU before further flight. Repetitive Testing (h) Repeat the testing specified in paragraph (f) of this AD at each functional test of the DECU Free Turbine Overspeed Protection System. Information on the functional tests of the DECU Free Turbine Overspeed Protection System can be found in the Engine Maintenance Manual, Section 77-30-01. Recommended intervals for the functional test of the Turbine Overspeed Protection System can be found in the Engine Maintenance Manual, Section 05-10-02. Alternative Methods of Compliance (i) The Manager, Engine CertificationOffice, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19. Related Information (j) DGAC airworthiness directive F-2005-063, dated April 27, 2005, and UF-2005, 063 R1, dated May 4, 2005, also address the subject of this AD. Material Incorporated by Reference (k) You must use Turbomeca Alert Mandatory Service Bulletin No. A319 77 0804, dated March 24, 2005, to perform the tests required by this AD. The Director of the Federal Register approved the incorporation by reference of this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Turbomeca S.A., 40220 Tarnos, France; telephone 33 05 59 74 40 00, fax 33 05 59 74 45 15, for a copy of this service information. You may review copies at the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL- 401, Washington, DC 20590-001, on the Internet at http://dms.dot.gov ; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html .

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 13, 2026. Connections as data: /graph/directive/2005-11-01.json · aircraft systems.