Discussion
The FAA is implementing a new process for streamlining the issuance of ADs related to MCAI. This streamlined process will allow us to adopt MCAI safety requirements in a more efficient manner and will reduce safety risks to the public. This process continues to allow all FAA AD issuance processes to meet legal, economic, Administrative Procedure Act, and Federal Register requirements. We also continue to meet our technical decision-making responsibilities to identify and correct unsafe conditions on U.S.-certificated products.
This AD references the MCAI and related service information that we considered in forming the engineering basis to correct the unsafe condition. The AD contains text copied from the MCAI and for this reason might not follow our plain language principles.
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 March 2, 2007 (72 FR 9475). That NPRM proposed to require inspecting the harness installation in the 120 VU (volt unit) electrical harness and, as applicable, restoring correct installation of the bonding cable. The MCAI states that recently an ATR 42 suffered electrical arcing, causing the loss of some instruments and loss of one hydraulic circuit pressure (i.e., loss of pressure of one hydraulic circuit) due to chafing between a bonding cable and electrical wires in the 120 VU electrical harness. The investigation showed that a tubular support had been deformed and therefore impaired the spacing among electrical harness, supports, and cables; the harness was not correctly attached; the size of the harness was increased by addition of cables (for Service Bulletins (SB) or customer modifications embodiments); and the bonding cable was not correctly installed. The MCAI mandates an inspection of the ATR 42 and ATR 72 fleet for correct installation of the bonding cable and restoring correct installation of the bonding cable if necessary.
Comments
We gave the public the opportunity to participate in developing this AD. We considered the comment received.
Request To Include Revised Service Bulletins
Avions de Transport Regional (ATR) states that in the NPRM reference is made to Avions de Transport Regional Service Bulletins ATR42-92-0012 and ATR72-92-1013, both dated July 4, 2006. ATR notes that this corresponds to the original issue of both service bulletins, and adds that those bulletins have been revised to add a reference to European Aviation Safety Agency Airworthiness Directive 2006-0283. ATR states that nothing else has been changed, and suggests that the AD reference Avions de Transport Regional Service Bulletins ATR42-92-0012 and ATR72-92-1013, both Revision 01, both dated December 7, 2006.
We agree to reference Revision 01 of the service bulletins in the AD. We have reviewed Revision 01 of the service bulletins, and the procedures are essentially the same as those in the original issues, as noted by ATR. We have changed paragraphs (e) and (g) of this AD to specify Revision 01 of the service bulletins.
Conclusion
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.
Differences Between This AD and the MCAI or Service Information
We have reviewed the MCAI and related service information and, in general, agree with their substance. But we might have found it necessary to use different words from those in the MCAI to ensure the AD is clear for U.S. operators and is enforceable in a U.S. court of law. In making these changes, we do not intend to differ substantively from the information provided in the MCAI and related service information.
We might also have required different actions in this AD from those in the MCAI in order to follow our FAA policies. Any such differences are described in a separate paragraph of the AD. These requirements, if any, take precedence over the actions copied from the MCAI.
Costs of Compliance
Based on the service information, we estimate that this AD affects about 53 products of U.S. registry. We also estimate that it takes about 1 work-hour per product to comply with this AD. The average labor rate is $80 per work-hour. Based on these figures, we estimate the cost of the inspection on U.S. operators to be $4,240, or $80 per product.
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 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); 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 AD and placed it in the AD Docket.
Examining the AD Docket
You may examine the AD docket on the Internet at http://dms.dot.gov ; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains the NPRM, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone (800) 647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new AD: