# AD 2014-07-06: Hydromechanical metering unit - Type: Airworthiness directive - Status: Current - Products: Turbomeca Arriel 2B1 - Effective: May 15, 2014 - Published: April 10, 2014, 79 FR 19812–19814 - Issued: April 2, 2014 - Issued as: Final rule - Supersedes: [AD 2007-19-09 R1](https://openairdocs.org/ad/2007-19-09-R1) - Superseded by: Nothing supersedes this AD - Product type: Engine - Amendment: 39-17820 - Docket: FAA-2007-27009 (https://www.regulations.gov/docket/FAA-2007-27009) - Project: 2007-NE-02-AD - Registered aircraft: 313 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/ff/24/ff24ddca2b7ad7e3359d9526a0f4d68be2824a4018e8803aa99b9bdfb155cb42 (from https://www.govinfo.gov/content/pkg/FR-2014-04-10/pdf/2014-08008.pdf) - Federal Register: https://www.federalregister.gov/documents/2014/04/10/2014-08008/airworthiness-directives-turbomeca-sa-turboshaft-engines - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B35012B3A18B559386257CB600445B12.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/2014-07-06 ## Summary We are superseding airworthiness directive (AD) 2007-19-09R1 for all Turbomeca S.A. Arriel 2B1 turboshaft engines that do not have modification TU157 incorporated. AD 2007-19-09R1 required replacement of the hydromechanical metering unit (HMU) with a serviceable HMU. This AD requires HMU replacement; reduction of the compliance interval; and inclusion of the power turbine C2 cycle consumption rate when determining compliance times. This AD was prompted by reports of ruptures on HMU constant delta pressure valves that have less than 2,000 hours in service. We are issuing this AD to prevent failure of the HMU, which could lead to damage to the engine, and damage to the aircraft. ## The airworthiness directive 1. The authority citation for part 39 continues to read as follows: 2. The FAA amends § 39.13 by removing airworthiness directive (AD) 2007-19-09R1, Amendment 39-16322 (75 FR 30687, June 2, 2010), and adding the following new AD: 2014-07-06 Turbomeca S.A.: Amendment 39-17820; Docket No. FAA-2007-27009; Directorate Identifier 2007-NE-02-AD. ### (a) Effective Date This AD is effective May 15, 2014. ### (b) Affected ADs This AD supersedes AD 2007-19-09R1, Amendment 39-16322 (75 FR 30687, June 2, 2010). ### (c) Applicability This AD applies to Turbomeca S.A. Arriel 2B1 turboshaft engines that do not have modification TU157 incorporated. ### (d) Unsafe Condition This AD was prompted by reports of ruptures on hydromechanical metering unit (HMU) constant delta pressure valves that have less than 2,000 hours in service. We are issuing this AD to prevent failure of the HMU, which could lead to damage to the engine, and damage to the aircraft. ### (e) Compliance Comply with this AD within the compliance times specified, unless already done. (1) HMU operating hours and power turbine C2 cycles are known: (i) If on the effective date of this AD, the HMU C2 cycles are less than 900, then replace the HMU before the HMU accumulates 1,000 C2 cycles or 1,500 HMU operating hours, whichever occurs first; (ii) If on the effective date of this AD, the HMU C2 cycles are 900 or more, then replace the HMU within 100 HMU C2 cycles after the effective date of this AD; (iii) Thereafter, replace the HMU at every 1,000 HMU C2 cycles or 1,500 HMU operating hours, whichever comes first. (2) HMU operating hours are known and C2 cycles are not known: (i) If on the effective date of this AD, the HMU operating hours are less than 1,100, then replace the HMU before accumulating 1,200 HMU operating hours; (ii) If on the effective date of this AD, the HMU operating hours are 1,100 or more, then replace the HMU within 100 HMU operating hours after the effective date of this AD; (iii) Thereafter, replace the HMU at every 1,200 HMU operating hours. ### (f) Definition For the purpose of this AD, HMU operating hours or C2 cycles are defined as operating hours or C2 cycles since new, since overhaul, or since incorporation of Turbomeca S.A. Service Bulletin (SB) No. 292 73 2105, Version B, dated December 16, 2010, or earlier version, or Turbomeca S.A. Mandatory SB (MSB) No. 292 73 2818, Version D, dated June 24, 2013, or earlier version. ### (g) Optional Terminating Action Incorporation of Turbomeca S.A. SB No. 292 73 2157, Version C, dated July 17, 2013, or earlier version, is terminating action to the replacement and repetitive inspection requirements of this AD. ### (h) Credit for Previous Actions If you performed the actions required by paragraphs (e)(1) or (e)(2) of this AD using an earlier version of Turbomeca S.A. MSB No. 292 73 2818, Version D, dated June 24, 2013, you met the requirements of this AD. However, you must still repetitively replace the HMU as required by paragraphs (e)(1)(iii) and (e)(2)(iii) of this AD. ### (i) Alternative Methods of Compliance (AMOCs) The Manager, Engine Certification Office, FAA, may approve AMOCs to this AD. Use the procedures found in 14 CFR 39.19 to make your request. ### (j) Related Information (1) For more information about this AD, contact James Gray, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7742; fax: 781-238-7199; email: james.e.gray@faa.gov. (2) Refer to MCAI European Aviation Safety Agency AD 2013-0171, dated July 30, 2013. You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2007-27009-0015. (3) Turbomeca S.A. MSB No. 292 73 2818, Version D, dated June 24, 2013, Turbomeca S.A. SB No. 292 73 2157, Version C, dated July 17, 2013, and Turbomeca S.A. SB No. 292 73 2105, Version B, dated December 16, 2010, which are not incorporated by reference in this AD, can be obtained from Turbomeca S.A. using the contact information in paragraph (j)(4) of this AD. (4) For service information identified in this AD, contact Turbomeca, S.A., 40220 Tarnos, France; phone: 33 (0)5 59 74 40 00; telex: 570 042; fax: 33 (0)5 59 74 45 1. (5) 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. ### (k) Material Incorporated by Reference None. ## Rule preamble ### Dates This AD is effective May 15, 2014. ### Addresses For service information identified in this AD, contact Turbomeca, S.A., 40220 Tarnos, France; phone: 33 5 59 74 40 00; telex: 570 042; fax: 33 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. ### For further information contact James Gray, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; phone: 781-238-7742; fax: 781-238-7199; email: james.e.gray@faa.gov. ### Discussion We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2007-19-09R1, Amendment 39-16322 (75 FR 30687, June 2, 2010), (“AD 2007-19-09R1”). AD 2007-19-09R1 applied to the specified products. The NPRM published in the Federal Register on December 24, 2013 (78 FR 77614). The NPRM proposed to continue to require HMU replacement. That NPRM also proposed to require reduction of the compliance interval; and inclusion of the power turbine C2 cycle consumption rate when determining compliance times. ### Comments We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM (78 FR 77614, December 24, 2013). ### Conclusion We reviewed the available data and determined that air safety and the public interest require adopting this AD as proposed. ### Costs of Compliance We estimate that this AD affects 264 engines installed on airplanes of U.S. registry. We also estimate that it will take about one hour per engine to comply with this AD. The average labor rate is $85 per hour. Required parts cost about $5,000 per engine. Based on these figures, we estimate the cost of this AD to U.S. operators is $1,342,440. ### Authority for This Rulemaking Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority. We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. ### Regulatory Findings This AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. For the reasons discussed above, I certify that this AD: (1) Is not a “significant regulatory action” under Executive Order 12866, (2) Is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), (3) Will not affect intrastate aviation in Alaska to the extent that it justifies making a regulatory distinction, and (4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. ### Adoption of the Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS E00054EN](https://openairdocs.org/tcds/E00054EN): Safran Helicopter Engines S.A.; names 1 of 9 models: Arriel 2B1 ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 313 (0 by airframe model, 313 by engine model) - Makers: Eurocopter 232, American Eurocopter 52, Eurocopter France 11, Airbus Helicopters 7, Airbus Helicopters Deutschland 6, Eurocopter Deutschland 4, Sikorsky 1 Models with the most aircraft: - [Turbomeca ARRIEL-2B1](https://openairdocs.org/engine/turbomeca-arriel-2b1): 271 aircraft (engine model) - [Turbomeca ARRIEL series](https://openairdocs.org/engine/turbomeca-arriel-series): 31 aircraft (engine model) - [Safran ARRIEL-2B1](https://openairdocs.org/engine/safran-arriel-2b1): 11 aircraft (engine model) All 3 models: https://openairdocs.org/ad/2014-07-06/models.md Every aircraft: https://openairdocs.org/ad/2014-07-06/aircraft.md ## Related documents - [AD 2007-19-09 R1](https://openairdocs.org/ad/2007-19-09-R1) (historical): Pressure relief valve · Turbomeca Arriel 2B1. Effective Jul 7, 2010. Replaced by this AD No proposed rule in this release led to it. Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.