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 CL-600-2C10 (Regional Jet Series 700, 701, & 702) airplanes, Model CL-600-2D15 (Regional Jet Series 705) airplanes, and Model CL- 600-2D24 (Regional Jet Series 900) airplanes. The NPRM published in the Federal Register on July 7, 2015 (80 FR 38656) (``the NPRM'').
Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued Canadian Airworthiness Directive CF- 2014-35, dated October 3, 2014 (referred to after this as the Mandatory Continuing Airworthiness Information, or ``the MCAI''), to correct an unsafe condition for certain Bombardier, Inc. Model CL-600-2C10 (Regional Jet Series 700, 701, & 702) airplanes, Model CL-600-2D15 (Regional Jet Series 705) airplanes, and Model CL-600-2D24 (Regional Jet Series 900) airplanes. The MCAI states:
It was discoveredthat some operators have inadvertently removed the existing insulation blankets from the upper wing box area while incorporating Bombardier Service Bulletin (SB) 670BA-36-016 to comply with [Canadian] AD CF-2012-06 [http://wwwapps3.tc.gc.ca/Saf-Sec-Sur/2/cawis-swimn/awd-lv-cs1401.asp?rand=] [which corresponds to FAA AD 2012-12-02, Amendment 39-17081 (77 FR 36129, June 18, 2012)].
Without insulation blankets on the upper wing box area, there may be inadequate thermal protection to prevent fuel ignition in the event of an undetected bleed air leak due to a cracked or ruptured bleed-air duct.
This [Canadian] AD mandates the inspection and rectification [i.e., replacement], as required, of the insulation blankets in the upper wing box area.
You may examine the MCAI in the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015- 2457.
Comments
We gave the public the opportunity to participate in developing this AD. The following presents the comments received on the NPRM and the FAA's response to each comment.
Request To Revise the Applicability
Bombardier and Endeavor Air requested that we exclude certain airplanes from the applicability. Bombardier stated that two airplanes, manufacturer serial numbers 15272 and 15279, should not be included in the applicability of the proposed AD, since these two airplanes had Bombardier Service Bulletin 670BA-36-016, Revision A, dated October 11, 2011, incorporated during production by the manufacturer. Therefore, Bombardier stated that those airplanes are not affected by the potential unsafe condition. Bombardier commented that proof of incorporation by Bombardier personnel can be provided to the FAA if required.
Endeavor Air stated that these airplanes accomplished Bombardier Service Bulletin 670BA-36-016, Revision A, dated October 11, 2011, prior to delivery to the operator.
We agree with the commenter's request for the reasons provided above. We have revised paragraph (c) of this AD accordingly.
Request To Provide Clarification of AD Actions
Endeavor Air stated that the proposed AD would require affected operators to inspect for missing thermal protection blankets using Bombardier Service Bulletin 670BA-57-024 because ``. . . some operators have inadvertently removed the existing insulation blanket from the upper wing box area while incorporating Bombardier Service Bulletin 670BA-36-016 to comply with FAA AD 2012-12-02. . . .''
Endeavor Air stated that the FAA did not provide any information why this may have occurred or that the problem is widespread. Endeavor Air also stated that Bombardier Service Bulletin 670BA-36-016 did not include instructions for removing the insulation blankets that were inadvertently removed by some operators. Endeavor Air therefore concluded that the operators or their maintenance provider did not correctly follow the instructions in Bombardier Service Bulletin 670BA- 36-016. Endeavor Air stated that it does not agree that the incorrect accomplishment of Bombardier Service Bulletin 670BA-36-016 by some operators should require all affected operators to perform the blanket inspections without a clear explanation why this problem could plausibly exist for all operators.
We agree that clarification is necessary. Bombardier has the service history and data showing a potential widespread problem, and TCCA concurred. Bombardier developed Bombardier Service Bulletin 670BA- 57-024 with a different effectivity than that of Bombardier Service Bulletin 670BA-36-016 in order to give credit to
[[Page 33365]]
airplanes on which the original blankets were not removed when Bombardier Service Bulletin 670BA-36-016 was incorporated. We have added an option to paragraph (g) of this AD to allow operators to do a records review in lieu of the inspection.
Request To Review Compliance Method
Endeavor Air requested the we review the last sentence in paragraph (g)(2) of the proposed AD. Endeavor Air stated that because the corrective action is to restore an already approved configuration by reinstalling insulation blankets, it believes that the corrective action using ``a method acceptable to the Manager, New York Aircraft Certification Office,'' rather than ``a method approved by the Manager, New York Aircraft Certification Office,'' would suffice.
We disagree with the commenter. The word ``approved'' is part of our standard language for describing methods of compliance in ADs. For a method to be ``acceptable,'' it must have FAA approval. We have not changed this AD is this regard.
Conclusion
We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting this AD with the changes described previously and minor editorial changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and
Do not add any additional burden upon the public than was already proposed in the NPRM.
Related Service Information Under 1 CFR Part 51
We reviewed Bombardier Service Bulletin 670BA-57-024, dated July 23, 2014. This service information describes procedures for an inspection of the insulation blankets in the upper wing box area to find if the blankets are installed, and replacement of missing insulation blankets. 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.
Costs of Compliance
We estimate that this AD affects 470 airplanes of U.S. registry.
We also estimate that it would 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 would cost about $0 per product. Based on these figures, we estimate the cost of this AD on U.S. operators to be $159,800, or $340 per product.
In addition, we estimate that any necessary follow-on actions would take up to 70 work-hours and require parts costing up to $665, for a cost of up to $6,615 per product. We have no way of determining the number of aircraft that might need this action.
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.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.