DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0030; Project Identifier MCAI-2020-01395-T]
RIN 2120-AA64

Airworthiness Directives; Bombardier, Inc., Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Bombardier, Inc., Model BD-700-1A10 airplanes. This
proposed AD was prompted by a report indicating that during
installation, a fuel pipe bracket assembly on the intermediate rib in
the center fuel tank was mislocated, resulting in an offset between the
fitting assembly and the refuel/defuel tube assembly. This proposed AD
would require modification of the fuel pipe bracket assembly, including
all related investigative actions and corrective actions, if necessary;
and performing an operational test of the refuel and defuel system. The
FAA is proposing this AD to address the unsafe condition on these
products.

DATES: The FAA must receive comments on this proposed AD by April 12, 2021.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:

Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow
the instructions for submitting comments.

Fax: 202-493-2251.

Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.

Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this NPRM, contact
Bombardier, Inc., 400 Cote-Vertu Road West, Dorval, Quebec
H4S 1Y9, Canada; telephone 514-855-5000; fax 514-855-7401; email
thd.crj@aero.bombardier.com; internet http://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.

Examining the AD Docket

You may examine the AD docket on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2021-
0030; or in person at Docket Operations between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays. The AD docket contains
this NPRM, any comments received, and other information. The street
address for Docket Operations is listed above. Comments will be
available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: 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.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include "Docket No. FAA-2021-0030; Project Identifier
MCAI-2020-01395-T" at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend the
proposal because of those comments.

Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
https://www.regulations.gov, including any personal information you
provide. The agency will also post a report summarizing each
substantive verbal contact received about this proposed AD.

Confidential Business Information

CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as "PROPIN." The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to
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. Any commentary that the FAA
receives which is not specifically designated as CBI will be placed in
the public docket for this rulemaking.

Discussion

Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued TCCA AD CF-2020-37, dated October 9,
2020 (referred to after this as the Mandatory Continuing Airworthiness
Information, or the MCAI), to correct an unsafe condition for certain
Bombardier, Inc., Model BD-700-1A10 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-2021-0030.

This proposed AD was prompted by a report indicating that during
installation, a fuel pipe bracket assembly on the intermediate rib in
the center fuel tank was mislocated, resulting in an offset between the
fitting assembly and the refuel/defuel tube assembly. The FAA is
proposing this AD to address the offset, which could cause a preload on
the fuel pipes and reduce their ability to absorb shock or vibration-
induced loads, making the tube and clamp more prone to stress corrosion
cracking. This could lead to failure of the coupling and the bracket
and p-clamp assembly, resulting in fuel leakage and loss of electrical
bonding between fuel pipes, and lightning-induced sparking that could
induce fuel ignition. See the MCAI for additional background
information.

Related Service Information Under 1 CFR Part 51

Bombardier has issued Service Bulletin 700-28-6006, dated June 1,
2020. This service information describes procedures for a modification
of the fuel pipe bracket assembly, including investigative actions (a
detailed visual inspection of the fuel pipe assembly for any damaged
paint, permanent deformation, corrosion, cracking, gouges, dents, or
deep scratches); installation of certain new parts; replacement of the
fuel pipe and fuel pipe bracket assembly, if necessary; and an
operational test of the refuel and defuel system. 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.

FAA's Determination

This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to the FAA's bilateral agreement with the State of Design Authority,
the FAA has been notified of the unsafe condition described in the MCAI
and service information referenced above. The FAA is proposing this AD
because the FAA evaluated all the relevant information and determined
the unsafe condition described previously is likely to exist or develop
on other products of the same type design.

Proposed Requirements of This NPRM

This proposed AD would require accomplishing the actions specified
in the service information described previously.

Costs of Compliance

The FAA estimates that this proposed AD affects 51 airplanes of
U.S. registry. The FAA estimates the following costs to comply with
this proposed AD:

Estimated Costs for Required Actions

The FAA estimates the following costs to do any necessary on-
condition action that would be required based on the results of any
required actions. The FAA has no way of determining the number of
aircraft that might need this on-condition action:

Estimated Costs of On-Condition Actions

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

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.

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.

Regulatory Findings

The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:

(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.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Proposed Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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 airworthiness
directive: