DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0141; Project Identifier MCAI-2021-01052-T]
RIN 2120-AA64

Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate
Previously Held by Bombardier, Inc.) Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (SNPRM).

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SUMMARY: The FAA is revising a notice of proposed rulemaking (NPRM)
that would have applied to all MHI RJ Aviation ULC Model CL-600-2B19
(Regional Jet Series 100 & 440) airplanes. This action revises the NPRM
by proposing to require an inspection for correct installation of the
flexible lamp assembly; trimming and reidentifying a bracket; and for
certain airplanes, an inspection for damage of
the wire harness assembly; and applicable corrective actions. The FAA
is proposing this airworthiness directive (AD) to address the unsafe
condition on these products. Since these actions would impose an
additional burden over those in the NPRM, the FAA is requesting
comments on this SNPRM.

DATES: The FAA must receive comments on this SNPRM by December 5, 2022.

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 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.
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2022-0141; or in person at Docket Operations between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD
docket contains the NPRM, this SNPRM, the mandatory continuing
airworthiness information (MCAI), any comments received, and other
information. The street address for Docket Operations is listed above.
Material Incorporated by Reference:
For service information identified in this SNPRM, contact
MHI RJ Aviation Group, Customer Response Center, 3655 Ave. des Grandes-
Tourelles, Suite 110, Boisbriand, Quebec J7H 0E2 Canada; North
America toll-free telephone 833-990-7272 or direct-dial telephone 450-
990-7272; fax 514-855-8501; email thd.crj@mhirj.com; website mhirj.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.

FOR FURTHER INFORMATION CONTACT: Gabriel Kim, Aerospace Engineer,
Avionics and Electrical Systems Section, FAA, New York ACO Branch, 1600
Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300;
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-2022-0141; Project Identifier
MCAI-2021-01052-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
this 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
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this SNPRM.

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 SNPRM 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 SNPRM, 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 SNPRM. Submissions containing CBI should
be sent to Gabriel Kim, Aerospace Engineer, Avionics and Electrical
Systems Section, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite
410, Westbury, NY 11590; telephone 516-228-7300; 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 an NPRM to amend 14 CFR part 39 by adding an AD that
would apply to all MHI RJ Aviation ULC Model CL-600-2B19 (Regional Jet
Series 100 & 440). The NPRM published in the Federal Register on
February 25, 2022 (87 FR 10752). The NPRM was prompted by AD CF-2021-
32, dated September 17, 2021, issued by Transport Canada Civil Aviation
(TCCA), which is the aviation authority for Canada (referred to after
this as the MCAI). The MCAI states that an oxygen-fed ground fire event
was potentially caused by electrical arcing from a faulty surround
light wire on the third crew member's (observer) oxygen mask. An
investigation determined that the oxygen supply hose connecting to the
rear of the observer oxygen mask box assembly could be subject to
chafing damage.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2022-0141.
In the NPRM, the FAA proposed to require an inspection for
discrepancies of the observer's oxygen mask stowage box and storage
compartment, oxygen hose connections and routing, and the associated
electrical harness, and corrective actions if necessary; and modifying
the oxygen mask flexible lamp harness, mounting plate, and compartment
panel, including rerouting the electrical harness and applying
protective sealant.

Actions Since the NPRM Was Issued

Since the FAA issued the NPRM, an operator reported a fouling
condition between the power feed wires for the stowage box light strip
and an existing aluminum bracket in the mask stowage compartment of the
entrance monument. MHI RJ determined that additional actions were
needed to further address the unsafe condition. TCCA subsequently
issued AD CF-2021-32R1, dated July 25, 2022, to require an additional
inspection for correct installation of the flexible lamp assembly;
trimming and reidentifying a bracket; and for certain airplanes, an
inspection for damage of the wire harness assembly; and applicable
corrective actions to address the fouling condition. The FAA is
proposing this AD to address possible damage to the observer oxygen
mask supply hoses and a potential for an oxygen-fed fire in the
vicinity of the observer oxygen mask storage compartment.

Comments

The FAA received comments from MHI RJ Aviation and Air Wisconsin.
The following presents the comments received on the NPRM and the FAA's
response to each comment.

Request To Incorporate Revised Service Information

MHI RJ Aviation and Air Wisconsin requested that the FAA
incorporate new service information into this proposed AD. MHI RJ noted
that when an operator performed the actions specified in the proposed AD, it
resulted in an unforeseen new potential fouling condition with the
existing bracket. MHI RJ stated that it had asked operators to not
complete the actions until revised service information, including
instructions to ensure clearance between the bracket and harness, was
available. Air Wisconsin requested that the proposed AD be revised to
include the new service information and additional work.
The FAA agrees and has revised this proposed AD to refer to Service
Bulletin 601R-35-022, Revision B, dated April 21, 2022, as the
appropriate source of service information to accomplish the required
actions. This service information includes additional work to address
the potential fouling condition.

Related Service Information Under 1 CFR Part 51

The FAA reviewed MHI RJ Service Bulletin 601R-35-022, Revision B,
dated April 21, 2022. This service information specifies procedures for
doing a general visual inspection for discrepancies, including elbow
fitting clocking (rotation), sealing tape installed in a certain
location, wire damage (e.g., cuts, nicks, kinks, insulation damage) of
the observer's oxygen mask stowage box and storage compartment, the
observer's mask oxygen hose connections, the hose routing, and the
associated electrical harness, and applicable corrective actions; and
modifying the oxygen mask flexible lamp harness, mounting plate, and
compartment panel, including rerouting the electrical harness and
applying protective sealant. Corrective actions include re-positioning
the elbow fitting, removing sealing tape, and repairing wiring. This
service information also specifies procedures for an inspection for
correct installation of the flexible lamp assembly; trimming and
reidentifying a bracket; and for certain airplanes, an inspection for
damage of the wire harness assembly; and applicable corrective actions.
Corrective actions include correcting flexible lamp assembly
installations and repair.
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 and Requirements of This SNPRM

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, it
has notified the FAA of the unsafe condition described in the MCAI and
service information referenced above. The FAA is issuing this SNPRM
after determining that the unsafe condition described previously is
likely to exist or develop on other products of the same type design.
Certain changes described above expand the scope of the NPRM. As a
result, it is necessary to reopen the comment period to provide
additional opportunity for the public to comment on this SNPRM.

Proposed AD Requirements in This SNPRM

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

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 407 airplanes of U.S. registry. The FAA estimates the following
costs to comply with this proposed AD:

Estimated Costs for Required Actions

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) 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 adding the following new airworthiness
directive: