AD 2021-03-10

This AD is effective March 31, 2021.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of March 31, 2021.

For service information identified in this final rule, contact Bombardier, Inc., 200 Côte Vertu Road West, Dorval, Québec H4S 2A3, Canada; North America toll-free telephone 1-866-538-1247 or direct-dial telephone 1-514-855-2999; email ac.yul@aero.bombardier.com; internet https://www.bombardier.com. You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. It is also available on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-0859.

Siddeeq Bacchus, Aerospace Engineer, Mechanical Systems and Administrative Services Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7362; fax 516-794-5531; email 9-avs-nyaco-cos@faa.gov.

Transport Canada Civil Aviation (TCCA), which is the aviation authority for Canada, has issued TCCA AD CF-2020-12, dated April 17, 2020 (TCCA AD CF-2020-12) (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for certain Bombardier, Inc., Model BD-100-1A10 airplanes. You may examine the MCAI in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-0859.

The FAA 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 BD-100-1A10 airplanes. The NPRM published in the Federal Register on October 1, 2020 (85 FR 61881). The NPRM was prompted by reports of failure of a certain FIREX control unit. The NPRM proposed to require replacing FIREX control units having a certain part number. The FAA is issuing this AD to address the failure of a FIREX control unit, which could result in the loss of the ability to detect a fire. See the MCAI for additional background information.

The FAA gave the public the opportunity to participate in developing this final rule. The following presents the comment received on the NPRM and the FAA's response to that comment.

NetJets requested that paragraph (i) of the proposed AD be revised to allow operators to review airplane maintenance records to determine the part number of the FIREX control unit installed on an airplane. The commenter stated that for the airplane having serial number (S/N) 20662 the logbook delivery document specifies that the -3 FIREX control unit is installed. The commenter explained that there is not a signoff sheet for Bombardier Service Bulletin 350-26-001, but that the serialized parts list clearly indicates that the -3 FIREX control unit is installed.

The FAA disagrees with the commenter's request because this AD does not mandate the method an operator must use to determine what FIREX control unit part number is installed on an airplane. As specified in paragraph (c) of this AD, this AD is only applicable to Bombardier, Inc., Model BD-100-1A10 airplanes fitted with FIREX control unit part number (P/N) 474112-2. If an operator is able to confirm that FIREX control unit P/N 474112-3 is installed on an airplane the requirements of this AD are not applicable to that airplane. This AD requires operators to remove FIREX P/N 474112-2 and install P/N 474112-3. The FAA has not changed this AD in regard to this issue.

The FAA reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting this final rule as proposed, except for minor editorial changes. The FAA has determined that these minor changes:

• Are consistent with the intent that was proposed in the NPRM for addressing the unsafe condition; and

• Do not add any additional burden upon the public than was already proposed in the NPRM.

Bombardier has issued Service Bulletin 100-26-01, Revision 01, dated December 5, 2019; and Service Bulletin 350-26-001, Revision 01, dated December 5, 2019. This service information describes procedures for replacing FIREX control units having P/N 474112-2 with units having P/N 474112-3. These documents are distinct since they apply to different airplane configurations. 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.

The FAA estimates that this AD affects 223 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:

According to the manufacturer, some or all of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected operators. The FAA does not control warranty coverage for affected operators. As a result, the FAA has included all known costs in the cost estimate.

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.

The FAA is 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.

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) Will not affect intrastate aviation in Alaska, 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.

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 airworthiness directive: