E8-25887. Airworthiness Directives; Turbomeca Arriel 2B and 2B1 Turboshaft Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

Several cases of loss of internal components from the Hydro Mechanical Unit (HMU) low fuel pressure switch Hydra-Electric part number (P/N) 9 550 17 956 0 into the fuel system, have been reported on Arriel 2 engines.

The loss of internal components from the low fuel pressure switch into the fuel system may lead to a rupture of the HP-LP pumps drive shaft shear pin, and thus to a possible uncommanded in-flight shutdown (IFSD). On a single-engine helicopter, an uncommanded IFSD results in an emergency autorotation landing and in certain conditions may lead to an accident.

We are proposing this AD to prevent forced autorotation landing, or an accident.

DATES:

We must receive comments on this proposed AD by December 1, 2008.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
• Fax: [phone].

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2008-0935; Directorate Identifier 2008-NE-28-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78).

Discussion

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA AD 2008-0077, dated April 28, 2008 (and corrected May 6, 2008) (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

Several cases of loss of internal components from the HMU low fuel pressure switch Hydra-Electric P/N 9 550 17 956 0 into the fuel system, have been reported on Arriel 2 engines.

The loss of internal components from the low fuel pressure switch into the fuel system may lead to a rupture of the HP-LP pumps drive shaft shear pin, and thus to a possible uncommanded IFSD. On a single-engine helicopter, an uncommanded IFSD results in an emergency autorotation landing and in certain conditions may lead to an accident.

The evaluation of this condition prompts the issuance of this AD, which requires the following actions for the HMUs installed on Arriel 2 single-engine applications in order to:

• Verify the part number of the low fuel pressure switch;
• If installed, replace the Hydra-Electric low fuel pressure switch P/N 9 550 17 956 0 (with either of two different P/N low fuel pressure switches, referenced in the MCAI).
• In case a Hydra-Electric switch P/N 9 550 17 956 0 is installed or may have been installed on the HMU, verify that no parts are found in the chamber of the HMU body where the base of the low fuel pressure switch has been installed.

You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Turbomeca has issued Mandatory Service Bulletin No. 292 73 2826, dated March 13, 2008. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of This Proposed AD

This product has been approved by the aviation authority of France, and is approved for operation in the United States. Pursuant to our bilateral agreement with France, they have notified us of the unsafe condition described in the EASA AD and service information referenced above. We are proposing this AD because we evaluated all information provided by EASA and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design. This proposed AD would require a one-time inspection for affected low fuel pressure switches, for evidence of an affected switch previously installed and inspection for switch parts missing or fallen into the HMU well.

Difference Between This Proposed AD and the MCAI or Service Information

We have reviewed the MCAI and related service information and, in general, agree with their substance. We have proposed to not reference the P/Ns of the serviceable low pressure switch as the MCAI does, in order to follow FAA policies. This difference is described in a separate paragraph of the proposed AD. This requirement, if ultimately adopted, will take precedence over the actions in the MCAI.

Costs of Compliance

Based on the service information, we estimate that this proposed AD would affect about 414 products installed on helicopters of U.S. registry. We also estimate that it would take about 1 work-hour per product to comply with this proposed AD. The average labor rate is $80 per work-hour. Required parts would cost about $256 per product. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $139,104. Our cost estimate is exclusive of possible warranty coverage.

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

We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

3. 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new AD:

Turbomeca: Docket No. FAA-2008-0935; Directorate Identifier 2008-NE-28-AD.

Comments Due Date

(a) We must receive comments by December 1, 2008.

Affected Airworthiness Directives (ADs)

(b) None.

Applicability

(c) This AD applies to Turbomeca Arriel 2B and 2B1 turboshaft engines. These engines are installed on, but not limited to, Eurocopter France AS350B3 and EC130 B4 helicopters.

Reason

(d) European Aviation Safety Agency (EASA) AD No. 2008-0077, dated March 13, 2006 (and corrected May 6, 2008), states:

Several cases of loss of internal components from the Hydro Mechanical Unit (HMU) low fuel pressure switch Hydra-Electric part number (P/N) 9 550 17 956 0 into the fuel system, have been reported on Arriel 2 engines.

The loss of internal components from the low fuel pressure switch into the fuel system may lead to a rupture of the HP-LP pumps drive shaft shear pin, and thus to a possible uncommanded in-flight shutdown (IFSD). On a single-engine helicopter, an uncommanded IFSD results in an emergency autorotation landing and in certain conditions may lead to an accident.

We are issuing this AD to prevent forced autorotation landing, or an accident.

Actions and Compliance

(e) Unless already done, do the following actions.

(1) No later than September 30, 2009, perform a one-time inspection of the HMU, using paragraph 2 of Turbomeca Mandatory Service Bulletin (MSB) No. 292 73 2826, dated March 13, 2008, to identify the low fuel pressure switch installed on the adjusted HMU.

(2) If a Hydra-Electric low fuel pressure switch, part number (P/N) 9 550 17 956 0 is installed:

(i) Inspect the low fuel pressure switch and chamber of the HMU body.

(ii) If any parts from the low fuel pressure switch are missing or found in the HMU chamber, replace the HMU with a new or overhauled HMU equipped with a serviceable low fuel pressure switch.

(iii) If not, replace only the low fuel pressure switch with a serviceable low fuel pressure switch.

(3) If a low fuel pressure switch other than a Hydra-Electric low fuel pressure switch, P/N 9 550 17 956 0 is installed, and that is the only type of low fuel pressure switch that has been installed since new, repair, or overhaul, no further action is required.

(4) If a Hydra-Electric switch, P/N 9 550 17 956 0, has been or may have been installed previously, and the conditions of paragraph (e)(3) of this AD are not met:

(i) Inspect the chamber of the HMU body.

(ii) If any parts are found in the HMU chamber, replace the HMU with a new or overhauled HMU equipped with a serviceable low fuel pressure switch.

FAA AD Difference

(f) This AD differs from the Mandatory Continuing Airworthiness Information (MCAI) and/or service information, by not referencing the P/Ns of the serviceable low fuel pressure switch, and, defining a serviceable low fuel pressure switch, for the purpose of this AD.

Definition

(g) For the purpose of this AD, a serviceable low fuel pressure switch is a switch that has a P/N other than P/N 9 550 17 956 0.

Alternative Methods of Compliance (AMOCs)

(h) The Manager, Engine Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested, using the procedures found in 14 CFR 39.19.

Related Information

(i) Refer to MCAI EASA AD 2008-0077, dated April 28, 2008 (and corrected May 6, 2008), for related information.

(j) Contact James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [e-mail]; telephone [phone]; fax [phone], for more information about this AD.

Issued in Burlington, Massachusetts, on October 23, 2008.

Peter A. White,

Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.