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2013-01-07: Hydro-mechanical metering unit (HMU)

FAA order 2013-01-07 is an airworthiness directive in force since March 7, 2013. The FAA's subject line: Hydro-mechanical metering unit (HMU). It names the Turbomeca (Safran) ARRIEL 2D engine: about 232 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
Arriel 2D
Engine series
Turbomeca (Safran) ARRIEL 2D 232 aircraft

Dates and paperwork

In force since
March 7, 2013
Published
January 31, 2013 (signed January 11, 2013)
Docket
FAA-2012-0940
Replaced by
2013-22-22
Status
Historical
The FAA's document
Read the order on the FAA's site

The FAA's summary their words, unchanged

We are adopting a new airworthiness directive (AD) for Turbomeca S.A. Arriel 2D turboshaft engines. This AD was prompted by a low fuel pressure event caused by deterioration and a loss of the low- pressure drive function within the hydro-mechanical metering unit (HMU). This AD requires replacing the HMU at a reduced life. We are issuing this AD to prevent an uncommanded in-flight shutdown of the engine, and possible loss of the helicopter.

The order itself the regulatory text, as published

Show the full text (2,770 characters)
Adoption of the Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: [[Page 6726]] PART 39--AIRWORTHINESS DIRECTIVES 0 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. Sec. 39.13 [Amended] 0 2. The FAA amends Sec. 39.13 by adding the following new AD: 2013-01-07 Turbomeca S.A.: Amendment 39-17321; Docket No. FAA-2012- 0940; Directorate Identifier 2012-NE-26-AD. (a) Effective Date This airworthiness directive (AD) becomes effective March 7, 2013. (b) Affected ADs None. (c) Applicability This AD applies to all Turbomeca S.A. Arriel 2D turboshaft engines. (d) Reason This AD was prompted by a low fuel pressure event caused by a deterioration and loss of the low-pressure drive function within the hydro-mechanical metering unit (HMU). We are issuing this AD to prevent an uncommanded in-flight shutdown of the engine, and possible loss of the helicopter. (e) Actions and Compliance Unless already done, replace the HMU with an HMU eligible for installation: (1) Before the HMU exceeds 800 operating hours since new; or (2) Within 800 operating hours since last replacement of the low-pressure pump spindle wheel assembly, high-pressure pump complete sleeve, bearings/pinions (matched assembly), and sleeve assembly. (f) Installation Prohibition After the effective date of this AD, do not install any HMU onto any engine, or install any engine onto any helicopter, unless in compliance with the requirements of paragraph (e) of this AD. (g) Alternative Methods of Compliance (AMOCs) The Manager, Engine Certification Office, may approve AMOCs for this AD. Use the procedures found in 14 CFR 39.19 to make your request. (h) Related Information (1) For more information about this AD, contact Frederick Zink, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; email: [email protected]; phone: 781-238-7779; fax: 781- 238-7199. (2) Refer to European Aviation Safety Agency AD No. 2012-0141, dated July 31, 2012, and Turbomeca S.A. Alert Mandatory Service Bulletin No. A292 73 2847, Version A, dated May 29, 2012, for related information. (3) For service information identified in this AD, contact Turbomeca, 40220 Tarnos, France; phone: 33 (0)5 59 74 40 00; telex: 570 042; fax: 33 (0)5 59 74 45 15. You may view this service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781-238-7125. (i) Material Incorporated by Reference None.

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 November 6, 2026. Connections as data: /graph/directive/2013-01-07.json · aircraft systems.