DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0911; Product Identifier 2020-NM-075-AD]
RIN 2120-AA64

Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate
Previously Held by 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 all MHI RJ Aviation ULC Model CL-600-2C10 (Regional Jet Series 700,
701 & 702) airplanes; Model CL-600-2C11 (Regional Jet Series 550)
airplanes; Model CL-600-2D15 (Regional Jet Series 705) airplanes; Model
CL-600-2D24 (Regional Jet Series 900) airplanes; and Model CL-600-2E25
(Regional Jet Series 1000) airplanes. This proposed AD was prompted by
a determination that a new or more restrictive airworthiness limitation
is necessary. This proposed AD would require revising the existing
maintenance or inspection program, as applicable, to incorporate a new
or more restrictive airworthiness limitation. 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 November
27, 2020.

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 MHI RJ
Aviation ULC, 12655 Henri-Fabre Blvd., Mirabel, Quebec J7N 1E1,
Canada; Widebody Customer Response Center North America toll-free
telephone +1-844-272-2720 or direct-dial telephone +1-514-855-8500; fax
+1-514-855-8501; email thd.crj@mhirj.com; internet https://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.

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-2020-0911;
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 participate in this rulemaking by submitting
written comments, data, or views about this proposal. The most helpful
comments reference a specific portion of the proposal, explain the reason
for any recommended change, and include supporting data. To ensure the
docket does not contain duplicate comments, commenters should send only
one copy of written comments, or if comments are filed electronically,
commenters should submit only one time. Send your comments to an
address listed under the ADDRESSES section. Include "Docket No. FAA-
2020-0911; Product Identifier 2020-NM-075-AD" at the beginning of your
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, as well
as a report summarizing each substantive public contact with FAA
personnel concerning this proposed rulemaking. Before acting on this
proposal, the FAA will consider all comments received by the closing
date for comments. The FAA will consider comments filed after the
comment period has closed if it is possible to do so without incurring
expense or delay. The FAA may change this NPRM because of those
comments.

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 the
person identified in the FOR FURTHER INFORMATION CONTACT section. 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 Canadian AD CF-2020-08, dated April 6,
2020 (referred to after this as the Mandatory Continuing Airworthiness
Information, or "the MCAI"), to correct an unsafe condition for all
MHI RJ Aviation ULC Model CL-600-2C10 (Regional Jet Series 700, 701 &
702) airplanes; Model CL-600-2C11 (Regional Jet Series 550) airplanes;
Model CL-600-2D15 (Regional Jet Series 705) airplanes; Model CL-600-
2D24 (Regional Jet Series 900) airplanes; and Model CL-600-2E25
(Regional Jet Series 1000) 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-2020-0911.

This proposed AD was prompted by a determination that a new or more
restrictive airworthiness limitation is necessary. This determination
follows a report that during maintenance, several telescopic ducts were
found jammed, and, in some cases, disconnected. Some of the failures
resulted in a slat fail message being posted on the engine indicating
and crew alerting system (EICAS).The telescopic duct slat attachment
movement during normal operation, combined with excessive friction
within the duct sliding joints, contributes to increased stress loads
on the duct, causing damage. The FAA is proposing this AD to address
failed telescopic ducts in the wing anti-ice system, which could result
in loss of the wing anti-ice system function, slat skew, slat jam,
structural damage to the slat panel, and loss of the slat panel,
possibly resulting in reduced control of the airplane. See the MCAI for
additional background information.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Bombardier Temporary Revision ALI-0721, dated
December 20, 2019. This service information describes safe life
limitation task 30-11-10-701 that specifies the life limitation for the
telescopic duct.

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 revising the existing maintenance or
inspection program, as applicable, to incorporate a new or more
restrictive airworthiness limitation.

This proposed AD would require revisions to certain operator
maintenance documents to include new actions (e.g., inspections).
Compliance with these actions is required by 14 CFR 91.403(c). For
airplanes that have been previously modified, altered, or repaired in
the areas addressed by this proposed AD, the operator may not be able
to accomplish the actions described in the revisions. In this
situation, to comply with 14 CFR 91.403(c), the operator must request
approval for an alternative method of compliance according to paragraph
(i)(1) of this proposed AD.

Explanation of Change to Manufacturer's Name Specified in This NPRM

The FAA has revised references to the manufacturer's name specified
throughout this NPRM to identify the manufacturer name as published in
the most recent type certificate data sheet for the affected models.

Costs of Compliance

The FAA estimates that this proposed AD affects 577 airplanes of
U.S. registry. The FAA estimates the following costs to comply with
this proposed AD.

The FAA has determined that revising the maintenance or inspection
program takes an average of 90 work-hours per operator, although the
agency recognizes that this number may vary from operator to operator.
In the past, the agency has estimated that this action takes 1 work-
hour per airplane. Since operators incorporate maintenance or
inspection program changes for their affected fleet(s), the FAA has
determined that a per-operator estimate is more accurate than a per-
airplane estimate. Therefore, the agency estimates the average total
cost per operator to be $7,650 (90 work-hours x $85 per work-hour).

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 prac-
tices, 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 (AD):