AD 2013-16-07

This AD is effective September 24, 2013.

The Director of the Federal Register approved the incorporation by reference of certain documents listed in this AD as of September 24, 2013.

For service information identified in this AD, contact American Eurocopter Corporation, 2701 N Forum Drive, Grand Prairie, TX 75052; telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; or at http://www.eurocopter.com/techpub. You may review the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

Gary Roach, Aviation Safety Engineer, Regulations and Policy Group, Rotorcraft Directorate, FAA, 2601 Meacham Blvd., Fort Worth, TX 76137; telephone (817) 222-5110; email gary.b.roach@faa.gov.

On April 22, 2013, at 78 FR 23686, the Federal Register published our notice of proposed rulemaking (NPRM), which proposed to amend 14 CFR part 39 to include an AD that would apply to Eurocopter Model AS332C, AS332L, AS332L1, AS332L2, and EC225LP helicopters, serial numbers (S/N) up to and including 2680 and S/N 9000 through 9009. The NPRM proposed to require inspecting for the presence of blind holes in the TGB attachment fittings, and, if they are missing, installing an additional washer under the head of the attachment bolt until the attachment fitting is replaced with an airworthy attachment fitting. The proposed requirements were intended to prevent insufficient tightening of the TGB casing, damage to the TGB attachment, cracking under the attachment bolt, and loss of the TGB, resulting in loss of control of the helicopter.

The NPRM was prompted by AD No. F-2007-027, dated January 2, 2008 (F-2007-027), issued by the Direction Générale de L'Aviation Civile France (DGAC), the aviation authority for France. DGAC issued F-2007-027 to correct an unsafe condition for certain Eurocopter AS332 series and EC225 LP helicopters. The DGAC advises that during a scheduled maintenance check, a helicopter was discovered to have interference between the threaded section of the aft attachment bolt and the structure fitting. The interference is because of a manufacturing anomaly in the fittings that omitted the blind hole for bolt clearance in the structure fitting. Interference from this missing blind hole does not permit correct axial tightening of the TGB casing, even if the correct torque load is applied to the attachment bolt. Insufficient tightening of the bolt can damage the TGB attachment and initiate a crack under the head of the attachment bolt. This condition, if not corrected, could result in loss of the TGB and subsequent loss of control of the helicopter.

We gave the public the opportunity to participate in developing this AD, but we received no comments on the NPRM (78 FR 23686, April 22, 2013).

These helicopters have been approved by the aviation authority of France and are approved for operation in the United States. Pursuant to our bilateral agreement with France, DGAC, which is the production oversight authority for France, has notified us of the unsafe condition described in its AD. We are issuing this AD because we evaluated all information provided by the DGAC and determined the unsafe condition exists and is likely to exist or develop on other helicopters of these same type designs and that air safety and the public interest require adopting the AD requirements as proposed.

Eurocopter has issued one Emergency Alert Service Bulletin (EASB), Revision 1, dated January 4, 2008, with four different numbers. EASB No. 53.01.58 is for the Model AS332 series helicopters; EASB No. 53.00.58 is for the Model AS532 series helicopters, which are not FAA type certificated; EASB No. 53A012 is for the Model EC225LP helicopter; and EASB No. 53A011 is for the Model EC 725AP helicopter, which is not FAA type certificated. The EASB specifies inspecting the forward and aft attachment fittings for proper depth of the bolt holes. If the bolt holes are less than the minimum depth, the EASB specifies checking the condition of the bolt. If there are no signs of chafing or contact, the EASB calls for adding an additional washer to the bolt and reinstalling the bolt in the TGB attachment fitting. If there are signs of chafing or contact, the EASB requires replacing the bolt with an airworthy bolt and two washers. The DGAC classified this EASB as mandatory and issued F-2007-027 to ensure the continued airworthiness of these helicopters.

We estimate that this AD affects six helicopters of U.S. registry. Based on an average estimated labor cost of $85 per work-hour, we estimate the following costs:

• Inspecting the TGB for the presence of a blind hole requires 0.50 work-hour for a labor cost of about $43. No parts are needed, so the cost totals $43 per helicopter, or $258 for the fleet.

• Replacing bolts and adding a second washer if needed requires 0.50 work-hour for a labor cost of about $43. Parts cost about $200 for three replacement bolts and the washers for a total cost of $243 per helicopter.

• Replacing the TGB attachment fitting with an airworthy fitting requires 40 work-hours for a labor cost of $3,400. Parts cost about $1,921 for a total cost of $5,321 per helicopter.

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 helicopters identified in this rulemaking action.

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.

We prepared an economic evaluation of the estimated costs to comply with this AD and placed it in the AD docket.

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

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