AD 2012-04-12

This AD becomes effective April 10, 2012.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of April 10, 2012.

You may examine the AD docket on the Internet at http://www.regulations.gov or in person at the U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE., Washington, DC.

Assata Dessaline, Aerospace Engineer, Avionics and Flight Test Branch, ANE-172, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone (516) 228-7301; fax (516) 794-5531.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM was published in the Federal Register on September 23, 2011 (76 FR 59067). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

Three (3) events have occurred where the Air-Driven Generator (ADG) failed to provide power on CL-600-2B19 (CRJ) aeroplanes during their regularly scheduled operational/functional checks. An investigation revealed that in all cases, the silver-plated copper wires within the ADG power feeder cables were damaged due to galvanic corrosion. It was subsequently determined that the silver-plating is inadequate for this application.

In the event of damage to the power feeder cable wires, the ADG may not be able to provide emergency electrical power to the aeroplane.

Although there have been no reported failures to date on any CL-600-2B16 (604 Variant) aeroplanes, a sampling program carried out on these aeroplanes showed signs of microscopic galvanic corrosion on the ADG power feeder cable wires.

This [Transport Canada] directive is issued to correct this potentially unsafe condition by mandating the replacement of all ADG power feeder cables * * * with an ADG power feeder cable that contains tin-plated copper wires.

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

We gave the public the opportunity to participate in developing this AD. We considered the comment received.

Bombardier Aerospace (Bombardier) commented that the aircraft applicability needs to be revised to remove two of the three model designations (Model CL-601-3A and -3R) specified in the NPRM (76 FR 59067, September 23, 2011), because only airplanes of the Model CL-604 Variant are affected by the proposed actions of the NPRM.

We agree to revise the applicability of this AD as requested. The airplane serial numbers specified in Transport Canada Civil Aviation (TCCA) Airworthiness Directive CF-2011-08, dated April 28, 2011 (cited in the NPRM (76 FR 59067, September 23, 2011) as the Canadian mandatory continuing airworthiness information (MCAI)), and Bombardier Service Bulletin 604-24-024, dated January 31, 2011 (cited as the appropriate service information for accomplishing the actions proposed by the NPRM) are all of the Model CL-604 Variant. We have changed the affected airplanes specified in the applicability in the Summary and in paragraph (c) of this AD accordingly.

We reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD with the change described previously. We determined that this change will not increase the economic burden on any operator or increase the scope of the AD.

We estimate that this AD will affect about 72 products of U.S. registry. We also estimate that it will take about 24 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Required parts will cost about $1,897 per product. Where the service information lists required parts costs that are covered under warranty, we have assumed that there will be no charge for these parts. As we do not control warranty coverage for affected parties, some parties may incur costs higher than estimated here. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $283,464, or $3,937 per product.

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.

We determined that 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 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);

3. Will not affect intrastate aviation in Alaska; 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 a regulatory evaluation of the estimated costs to comply with this AD and placed it in 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 the NPRM (76 FR 59067, September 23, 2011), the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

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 AD: