AD 2012-23-05

This AD is effective December 26, 2012.

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.

George Schwab, Aviation Safety Engineer, FAA, Rotorcraft Directorate, Safety Management Group, 2601 Meacham Blvd., Fort Worth, Texas 76137; telephone (817) 222-5114; email george.schwab@faa.gov.

On May 22, 2012, at 77 FR 30230, 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 ECD Model MBB-BK117 C-2 helicopters with a GCU, part number (P/N) 51530-021EI with no modification (MOD), MOD A, or MOD B installed. That NPRM proposed to require replacing the GCU within 300 hours time-in-service (TIS) or 6 months, whichever occurred earlier. The proposed requirements were intended to prevent loss of electrical generating power, resulting in the loss of systems required for continued safe flight and landing, and subsequent loss of control of the helicopter.

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA AD No. 2011-0149R1, dated September 30, 2011 (AD 2011-0149R1), to correct an unsafe condition for the Eurocopter Deutschland GmbH Model MBB-BK117 C-2 helicopters. EASA advises that during an acceptance test procedure of a GCU, a short circuit caused by a manufacturing discrepancy occurred within the unit. According to EASA, all P/N 51530-021EI “no MOD,” “MOD A,” and “MOD B” GCUs are potentially affected by this discrepancy. To address this potential unsafe condition, EASA issued AD No. 2011-0149, dated August 19, 2011, to identify and replace each affected GCU with an airworthy GCU. Since issuing that AD, ECD demonstrated that helicopters modified in accordance with ECD Alert Service Bulletin (ASB) MBB BK117 C-2-24A-008, Revision 1, dated August 29, 2011, have a much lower risk of losing electrical generating power from a faulty generator control unit. EASA then revised AD No. 2011-0149 and issued AD 2011-0149R1 to allow an extended compliance time for helicopters modified in accordance with the ECD ASB.

We gave the public the opportunity to participate in developing this AD, but we did not receive any comments on the NPRM (77 FR 30230, May 22, 2012).

These helicopters have been approved by the aviation authority of Germany and are approved for operation in the United States. Pursuant to our bilateral agreement with Germany, EASA, its technical representative, has notified us of the unsafe condition described in the EASA AD. We are issuing 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 helicopters of these same type designs and that air safety and the public interest require adopting the AD requirements as proposed.

The EASA AD allows a compliance time of 1,500 flight hours for helicopters previously modified by ECD ASB MBB BK117 C-2-24A-008 Revision 1, while this AD requires compliance within the next 300 hours TIS or 6 months, whichever occurs first, for all affected helicopters.

ECD has issued ASB MBB-BK117 C-2-24A-010 Revision 2, dated September 14, 2011, which specifies removing any GCU with P/N 51530-021EI with no modification (MOD), MOD A, or MOD B, and replacing it with a GCU P/N 51530-021EI MOD C or later MOD. EASA classified this ASB as mandatory and issued AD 2011-0149R1 to ensure the continued airworthiness of these helicopters.

We estimate that this AD will affect 104 helicopters of U.S. Registry. We estimate that operators may incur the following costs in order to comply with this AD. Replacing a GCU with an airworthy GCU will require about 2 work hours at an average labor rate of $85 per hour. Required parts will cost $7,130, for a total cost per helicopter of $7,300.

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:

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):