DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0725; Project Identifier MCAI-2020-01402-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 supersede Airworthiness Directive (AD)
2017-22-06, which applies to certain Bombardier, Inc., Model CL-600-
2B16 (601-3A, 601-3R, and 604 Variants) airplanes. AD 2017-22-06
requires repetitive inspections for fuel leakage at the engine and
auxiliary power unit (APU) fuel pumps, and related investigative and
corrective actions if necessary. Since the FAA issued AD 2017-22-06,
terminating actions have been developed and additional airplanes have
been determined to be affected by the unsafe condition. This proposed
AD would retain the requirements of AD 2017-22-06, and require an
inspection of the APU, repair if necessary, and modification of the
engine electrical fuel pump (EFP) installation. This proposed AD would
also add airplanes to the applicability. 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 October 25, 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., 200 C[ocirc]te-Vertu Road West, Dorval, Qu[eacute]bec
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.

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-
0725; 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.

FOR FURTHER INFORMATION CONTACT: Steven Dzierzynski, Aerospace
Engineer, Avionics and Electrical Systems Section, FAA, New York ACO
Branch, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone
516-228-7367; 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-2021-0725; Project Identifier
MCAI-2020-01402-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
Steven Dzierzynski, Aerospace Engineer, Avionics and Electrical Systems
Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; telephone 516-228-7367; 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.

Background

The FAA issued AD 2017-22-06, Amendment 39-19086 (82 FR 49498,
October 26, 2017) (AD 2017-22-06), for certain Bombardier, Inc., Model
CL-600-2B16 (601-3A, 601-3R, and 604 Variants) airplanes. AD 2017-22-06
requires repetitive inspections for fuel leakage at the engine and APU
fuel pumps, and related investigative and corrective actions if
necessary. AD 2017-22-06 resulted from reports of fuel leaks in the
engine and APU EFP cartridge/canister electrical connectors and
conduits. The FAA issued AD 2017-22-06 to address fuel leaks in certain
fuel pumps to remove a potential fuel ignition hazard. FAA AD 2017-22-
06 corresponds to AD CF-2016-32R1, dated October 12, 2016, issued by
Transport Canada Civil Aviation (TCCA), which is the aviation authority
for Canada.

Actions Since AD 2017-22-06 Was Issued

The preamble to AD 2017-22-06 explains that the FAA considered the
requirements "interim action" and was considering further rulemaking.
The FAA has now determined that further rulemaking is indeed necessary,
and this proposed AD follows from that determination.

Since the FAA issued AD 2017-22-06, a general visual inspection of
the APU and a modification of the engine EFP installation have been
developed to address the root cause of the fuel leaks and provide
terminating action for the repetitive general visual inspections and
rectifications of fuel leaks from the engine and APU EFP electrical
wiring conduit outlets. In addition, it was determined that additional
airplanes are affected by the unsafe condition.

TCCA has issued TCCA AD CF-2016-32R4, dated October 13, 2020 (TCCA
AD CF-2016-32R4); and TCCA AD CF-2020-38, dated October 13, 2020 (TCCA
AD CF-2020-38); to correct an unsafe condition for certain Bombardier,
Inc., Model CL-600-2B16 (601-3A, 601-3R, and 604 Variants) airplanes.
This proposed AD refers to the TCCA ADs as the Mandatory Continuing
Airworthiness Information, or the MCAI. 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-2021-0725.

This proposed AD was prompted by reports of fuel leaks from the
electrical connectors and conduits of the engine and APU EFP cartridge/
canister, and additional actions have been developed to address the
root cause of the fuel leaks. The FAA is proposing this AD to address
the potential for a fire hazard as a result of fuel leak from the APU
EFP electrical conduit in the hot landing light compartment. See the
TCCA ADs for additional background information.

Related Service Information Under 1 CFR Part 51

Bombardier has issued the following service information, which
describes procedures for repetitive general visual inspections and
rectifications for any fuel leak from the engine and APU EFP electrical
wiring conduit outlets. These documents are distinct since they apply
to different airplane serial numbers.

Bombardier Service Bulletin 604-28-022, Revision 3, dated August 31, 2018.

Bombardier Service Bulletin 605-28-010, Revision 3, dated August 31, 2018.

Bombardier Service Bulletin 650-28-001, Revision 3, dated January 3, 2019.

Bombardier has also issued the following service information, which
describes procedures for a detailed visual inspection of the APU for
any damage or deformations (e.g., cut wires and a broken harness
assembly of the fuel boost pump connector), modifying
the engine EFP installation, and repair if necessary. These documents
are distinct since they apply to different airplane serial numbers.

Bombardier Service Bulletin 604-28-024, dated June 16, 2020.

Bombardier Service Bulletin 650-28-002, dated June 16, 2020.

Bombardier Service Bulletin 605-28-012, dated June 16, 2020.

This proposed AD would also require Bombardier Service Bulletin
604-28-022, dated October 19, 2015, and Bombardier Service Bulletin
605-28-010, dated October 19, 2015, which the Director of the Federal
Register approved for incorporation by reference as of November 30,
2017 (82 FR 49498, October 26, 2017).

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 retain all of the requirements of AD 2017-
22-06 and require accomplishing the actions specified in the service
information described previously, except as discussed under
"Difference Between this Proposed AD and the MCAI.

Difference Between This Proposed AD and the MCAI

Paragraph E.1. of TCCA AD CF-2016-32R4, for airplane serial numbers
6125 through 6163, requires inspecting for fuel leaks within 600 hours
or 12 months, whichever occurs first after "the date of aeroplane
entry in-service." Paragraph (i) of this proposed AD, however, would
require compliance for those airplanes within 600 flight hours or 12
months, whichever occurs first after "the effective date of this [FAA]
AD." Paragraph D.1. of TCCA AD CF-2016-32R4 requires compliance for
this action for other serial numbers within 600 flight hours or 12
months after the effective date of the AD. The FAA has determined that
the risk is not higher for serial numbers 6125 through 6163 compared
with the other identified airplanes required to accomplish the same
inspection. Therefore, for this AD, the compliance time is the same for
all airplanes that are required to inspect for fuel leaks.

Costs of Compliance

The FAA estimates that this proposed AD affects 128 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 repair
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 repair:

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 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.

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 has 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) Would not affect intrastate aviation in Alaska, and

(3) Would 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:

a. Removing Airworthiness Directive (AD) 2017-22-06, Amendment 39-19086
(82 FR 49498, October 26, 2017), and

b. Adding the following new AD: