Discussion
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 October 16, 2012 (77 FR 63281). That NPRM proposed to correct an unsafe condition for the specified products. The Mandatory Continuing Airworthiness Information (MCAI) states:
There have been two reported in-service incidents where the left main landing gear (MLG) failed to extend. The investigation revealed that in both cases, the uplock assembly had been replaced prior to the in-service incidents and the upper bolt of the uplock assembly was incorrectly installed. The incorrect installation of the upper bolt resulted in the uplock assembly pivoting on the lower attachment bolt and preventing the MLG from extending under normal or alternate extension.
The potential for an incorrect installation of the upper bolt could occur at both the left handside (LHS) and/or the right hand side (RHS) MLG uplock assembly. Failure of the MLG to extend could adversely affect the safe landing of the aeroplane.
This [Canadian] AD mandates the installation of stopper plates on the aft uplock frames in the MLG bay, adjacent to both the RHS and LHS MLG uplock assemblies, to prevent an incorrect installation of the MLG uplock assembly.
You may obtain further information by examining the MCAI in the AD docket.
Actions Since the NPRM (77 FR 63281, October 16, 2012) Was Issued
We have reviewed Bombardier Service Bulletin 601R-32-109, Revision A, dated February 26, 2013. In the NPRM (77 FR 63281, October 16, 2012), we referred to Bombardier Service Bulletin 601R-32-109, dated May 29, 2012, as the appropriate source of service information for doing the actions specified in the NPRM. Revision A of the service information adds information for parts that are listed in paragraph 1.G. ``Material--Price and Availability,'' and small editorial changes that do not have an effect on the technical content of the service information.
We have updated paragraphs (g) and (j) of this AD to refer to Bombardier Service Bulletin 601R-32-109, Revision A, dated February 26, 2013. We have also added a new paragraph (h) to this AD to give credit for actions done before the effective date of this AD, using Bombardier Service Bulletin 601R-32-109, dated May 29, 2012, and re-identified the subsequent paragraph identifiers accordingly.
Comments
We gave the public the opportunity to participate in developing this AD. We have considered the comments received.
The National Transportation Safety Board supported the NPRM (77 FR 63281, October 16, 2012).
Request To Shorten the Compliance Time
The Air Line Pilots Association International (ALPA) requested that the proposed compliance time in the NPRM (77 FR 63281, October 16, 2012) be shortened from ``Within 5,500 flight hours or 48 months after the effective date of this AD, whichever occurs first . . . .'' to ``Within 2,400 flight hours or 24 months after the effective date of the AD, whichever occurs first . . . .'' The ALPA based its suggested compliance time on the two reported in-service incidents and the potential safety implication of landing with an MLG fully or partially retracted.
We do not agree with the request to shorten the compliance time. The proposed compliance time in the NPRM (77 FR 63281, October 16, 2012) was based on a risk assessment completed by the airplane manufacturer, Bombardier, Inc. The risk was conservatively assessed with a compliance time of 6,000 flight hours, based on the estimated release date of Bombardier service information. Transport Canada Civil Aviation (TCCA), the State of Design Authority,
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concurred with Bombardier, Inc.'s risk assessment. Bombardier, Inc. reduced the compliance time from 6,000 flight hours to 5,500 flight hours because the release date of the service informationwas delayed. Also, the compliance time of 5,500 flight hours or 48 months after the effective date of this AD, whichever occurs first, corresponds with the compliance time of parallel TCCA AD CF-2012-22, dated July 24, 2012. We have not changed the AD in this regard.
Request To Add a Required Inspection Item
The ALPA also recommended that, until operators have complied with the proposed AD (77 FR 63281, October 16, 2012), the operators be required to have a Required Inspection Item for any maintenance work involving the upper MLG assembly. The ALPA recommended this requirement to ensure correct installation of the upper MLG assembly until the proposed AD is complied with.
We do not agree with this recommendation. If operators properly follow the instructions in the airplane maintenance manual, the upper MLG uplock assembly will be correctly installed. In addition, Bombardier, Inc. issued All Operators Message No. 1307, dated September 6, 2011, to inform operators of thesecond in-flight MLG incident; and Service Letter CRJ100/200/440-SL-32-046, dated October 11, 2011, to provide additional information and recommendations to address the second in-flight MLG incident. We have not changed the AD in this regard.
Conclusion
We reviewed the available data and determined that air safety and the public interest require adopting the AD with the changes described previously-and minor editorial changes. We have determined that these changes:
Are consistent with the intent that was proposed in the NPRM (77 FR 63281, October 16, 2012) for correcting the unsafe condition; and
Do not add any additional burden upon the public than was already proposed in the NPRM (77 FR 63281, October 16, 2012).
Costs of Compliance
We estimate that this AD will affect 574 products of U.S. registry. We also estimate that it will take about 5 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour.Based on these figures, we estimate the cost of this AD to the U.S. operators to be $243,950, or $425 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 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.
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 the NPRM (77 FR 63281, October 16, 2012), 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.