Discussion
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain Bombardier, Inc. Model DHC-8-400 series airplanes. The NPRM published in the Federal Register on March 24, 2015 (80 FR 15521).
Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian Airworthiness Directive CF- 2014-22, dated July 16, 2014 (referred to after this as the Mandatory Continuing Airworthiness Information, or ``the MCAI''), to correct an unsafe condition for certain Bombardier, Inc. Model DHC-8-400 series airplanes. The MCAI states:
Although [Canadian] AD CF-2009-26 [dated May 21, 2009 (http://wwwapps3.tc.gc.ca/Saf-Sec-Sur/2/CAWIS-SWIMN/attachment.asp?aiid=CF-2009-26&revid=0&cntr=CF&file=CFCF-2009-26.pdf&type=PDE), which corresponds to FAA AD 2009-25-05, Amendment 39-16124
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(74 FR 63574, December 4, 2009)] was issued to mandate the upgrade of the spoiler lift/dump valve, it did not reduce the rate of inadvertent single spoiler deployment occurrences. Further investigation revealed that the outboard spoiler PCUs may also be subject to pressure reversals at the PCU main control valve seal, resulting in leakage at the piston head seal and piston rod seals. If not corrected, this condition may result in [inadvertent spoiler deployment and] reduced controllability of the aeroplane.
This [Canadian] AD mandates the replacement of the existing outboard spoiler PCUs with the upgraded PCUs with re-designed seals for better leakage protection.
You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA-2015-0494-0002.
Comments
We gave the public the opportunity to participate in developing this AD. The following presents the comment received on the NPRM (80 FR 15521, March 24, 2015) and the FAA's response to that comment.
Request To Revise Applicability
Horizon Air requested that the applicability of the NPRM (80 FR 15521, March 24, 2015) be revised to specify that the NPRM would only be applicable to airplanes with outboard spoiler PCU part number (P/N) 390700-1007 installed. The commenter noted that the illustrated parts catalog for the Bombardier, Inc. Model DHC-8-400 series airplanes indicates that outboard spoiler PCU P/N 390700-1009 is a direct replacement for P/N 390700-1007, and that these two part numbers are one way interchangeable. The commenter stated that operators who replaced outboard spoiler PCU P/N 390700-1007 with P/N 390700-1009 prior to the effective date of the NPRM might not have recorded the incorporation of Bombardier Service Bulletin 84-27-63, dated October 17, 2013, into their maintenance records and it would be an unnecessary regulatory burden for those operators to go back and record this service information. The Accomplishment Instructions of Bombardier Service Bulletin 84-27-63, dated October 17, 2013, state that the PCU should be replaced using the guidance in the Bombardier, Inc. Model DHC-8-400 Aircraft Maintenance Manual; therefore the actions that would be mandated by the NPRM would have been accomplished.
We agree with the commenter's request based on the information provided by the commenter. We have revised paragraph (c), ``Applicability,'' of this final rule to specify that only airplanes having certain serial numbers and an outboard spoiler PCU having P/N 390700-1007 installed are affected by the requirements of this final rule.
Conclusion
We reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting this AD with the change described previously and minor editorial changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the NPRM (80 FR 15521, March 24, 2015) for correcting the unsafe condition; and
Do not add any additionalburden upon the public than was already proposed in the NPRM (80 FR 15521, March 24, 2015).
We also determined that these changes will not increase the economic burden on any operator or increase the scope of this AD.
Related Service Information Under 1 CFR Part 51
Bombardier, Inc. has issued Service Bulletin 84-27-63, dated October 17, 2013. The service information describes procedures for replacement of the existing outboard spoiler PCUs with upgraded PCUs. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section of this AD.
Costs of Compliance
We estimate that this AD affects 82 airplanes of U.S. registry.
We also estimate that it will take about 4 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 $0 per product. Based on thesefigures, we estimate the cost of this AD on U.S. operators to be $27,880, or $340 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.
Examining the AD Docket
You may examine the AD docket on the Internet at http://www.regulations.gov/#!docketDetail;D=FAA-2015-0494; or in person at the Docket Management Facility between9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, 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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.